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Ez-EFI 1. Question regarding PCV

Discussion in 'FAST Support Forum' started by Narler, Jan 2, 2016.

  1. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    I'm still hunting for the best tuning for my engine (427 FE, with Dual Quad Ez-EFI 1). Specifically relating to fuel consumption and A/F ratios.

    The question I have today is how does the Ez-EFI work out how much additional air is being drawn in by the PCV? I've done a search on the forum but not found any reference to PCV.

    My engine (when looking from the front) at the moment has breather on the left side valve cover. On the right side valve cover is the PCV connected to 3/8" hose that connects to the ford lowriser dual plane dual manifold. (in the middle of both throttle bodies).

    As this air is being drawn in below the throttle bodies the Ez-Efi has no ability to monitor this, until readings are taken by the o2 sensor, which then tries to correct.

    Fuel consumption of my engine seems very high and I'm wondering if the ECU is detecting a lean condition due to the additional air from the PCV and dumping more fuel in to compensate. On the hand held, at idle of 850rpm with the engine warm, it is showing 006 lb/hr for fuel. 1000rpm fuel rate goes to 012 lb/hr (A/F ratio currently set at 14.7 for idle and for cruise).

    Should I connect the PCV to one of the 3/8" vacuum ports on the throttle body? Would that provide any benefit to the ECU, or are those vacuum ports below the sensors anyway?

    Should I continue to use a PCV or remove it completely?

    Thanks for any thoughts / opinions or suggestions.
     
  2. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    You definitely need the PCV. It prevents oil contamination due to condensation and helps maintain a slightly negative pressure on the crankcase. When you setup the IAC you compensate for air that comes in via the PCV.

    A 14.7 A/F is the "ideal" A/F but most engines are not happy running at 14.7 and will not make good power or get good fuel economy at that A/F. What happens when you are that lean is that the engine makes less power and because of that you have to give the engine more throttle thus consuming more fuel than you would with a richer mixture.

    My engine runs at 13.6 at idle and 14.1 at cruise and 12.5 at WOT. Some engines will not be happy at 14.1 and will need an A/F in the mid to high 13's. The heads and cam are the major factors in determining how lean you can go and the newer unmodified engines will usually tolerate the leaner mixtures. If you lack power or throttle response or get surging your engine is probably too lean.

    At idle you will find the best mixture is where you have the greatest vacuum and using that as a starting point you can lean it out a little from that point for better exhaust emissions.
     
    Last edited: Jan 2, 2016
  3. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi Denis,

    Thanks for the reply. I was hoping to do a few more tests before replying but it's been raining so thought I'd reply now with my current findings.

    What I'm seeing with my engine doesn't match what people keep saying I should be seeing.

    First up the fuel economy. It's bad. Driving style is light on throttle and use no more than 20% throttle at any point. Averaging consumption over 7 tanks of fuel is 6.6 MPG (that is US gallon. worst 5.41MPG, best 9MPG). That equates to 36lt of fuel per 100km. ( I have a 85lt fuel tank ) So I set the A/F ration to 15.9 (max on the hand held) and run the car for another 7 tanks of fuel. The average was is 7.2MPG (worst 6.76MPG best 11MPG). That's an average of 32lt of fuel per 100km. I also set the Accel pump to -6. So some fuel saving benefits are clearly visible.

    With A/F at 14.7 the car runs fantastic. Instant throttle response, no lag, no delay, no bog. With the A/F at 15.9 the car is still great but there's a slightly lag if you tap the throttle quickly (say to pull out and overtake on the highway, but that could be due to -6 Accel pump), so it's not quite as responsive at higher rpm. It is also slightly harder to keep it running when dead cold, so takes a bit of throttle work for 10 seconds then it's fine, but other than that no problems. But fuel usage still feels way too high considering how I'm driving it. Driving at 80kmph only uses 3 or 4% throttle, so driving around town uses 2 - 3 % throttle.

    With the Vacuum. I'm not seeing on my gauges what you (or any other website that I've read researching this) state. I do not make my most vacuum at idle. At Idle (850rpm in neutral) the gauge jumps around 7 - 8 hg. At 1000rpm it makes 10 hg, tap the throttle and it makes 15 hg, 10% throttle and it makes 20hg. These values are duplicated while driving. So during throttle applications I've seen 25 hg. Yes vacuum goes UP when applying throttle. I've tested with 4 gauges and tried different vacuum ports just to rule out any possible faulty equipment. They all show the same. I should clarify this is throttle applications of less than 20%. That is where I spend most of my driving time.

    What I did then was to see what impact the PCV had, so I put a vacuum gauge inline (between manifold to PCV) then went for a drive. Now at idle the gauge reads 5 - 6 hg, at 1000rpm it reads 10hg. So while driving (3% throttle) gauge reads 13 hg, now I apply more throttle. the gauge drops to 9hg then after a second or two jumps to 15hg (or higher). Back off the throttle (from 3%) and vacuum goes up.

    So the difference between the vacuum gauge readings and then the vacuum gauge readings influenced by the PCV is that the PCV affects how many inches hg are available as it opens / closes. Has anyone else actually tested like this, to see what effect PCV has on their system?

    From what I can understand (and from reading the sticky post on the forum (from pbp1) vacuum is important for how the system calculates what to do, so if the PCV is altering that and the fact I'm not seeing readings that correspond to that sticky post, then I have no idea what my system is trying to do (learn) based on the values I'm seeing. Then there is the main question I ask about how the system works out the additional air induction from the PCV. Reading my vacuum gauges while driving I can see when the PCV is opening as the vacuum drops and it does that at throttle application, so at IDLE the PCV seems to make very little impact (~1hg), which means adjusting the idle to compensate for that increase in air is not going to equate to how much air it's actually drawing in at higher RPM and throttle usage (which has been ~9hg)

    The main thing I'm trying to work out is why there is so much fuel entering the system. Driving the other day sitting on 80kmph (3% throttle) and the hand held was showing -25% for the O2 correction constantly (AF set to 14.7, actual A/F was reported as 14.3). Wish this handheld could capture data! I'm going to set up a dash camera facing the gauges and handheld to record all the values but it's raining now.

    You did reply to one of my older threads, so I'll add the link here incase there's additional information in that which is helpful http://www.cpgnation.com/forum/threads/ez-efi1-dual-quad-voltage-and-fuel-usage-issue.25279/

    In case this is of additional interest (with PCV connected and my vacuum gauge inline). checking the MAP and LOAD values in relation to throttle (TPS). At idle (000 TPS), MAP and LOAD are both 71. at 001 TPS, MAP and LOAD are both at 66, at 002 TPS, MAP and LOAD are at 64, at 005 TPS MAP and LOAD are 59.

    A/F is set to 14.7. Now applying 35% throttle (035 TPS) MAP and LOAD are 90, A/F actual is 11.5, -25% O2 correction. Injectory duty 021 and 106 lb/hour fuel. (engine rpm at this time is 3,750). Mean while the car has launched hard and is proceeding to vaporise the rear tyres when shifting into second. (c6 auto)

    A/F is set to 14.7. constant cruise at 5% throttle (005 TPS), engine 2,100RPM, MAP and LOAD 58, A/F actual 14.2 A/F -05% O2, Inj DC % 003 lb/hour 014. My Vacuum gauge reads 11 hg. Also the longer I cruise at that 005 TPS, MAP and LOAD get lower. 30 seconds later they are 53.

    What is strange though is IAC is 045? Why does that move around while driving, I thought that was just for Idle management not when driving? at 005TPS it was reading 045, as I slow down for a corner 004 TPS IAC now reads 036, 002 TPS now is 022 IAC, 001 TPS now is 016 IAC, but I'm still doing 1950rpm, so not even close to idle and my road speed is 70kmph. When i re-apply the throttle to 004 TPS IAC goes back to 036. 006TPS and IAC is now 52 and Vacuum gauge reads 13 hg. Is this normal operation for the IAC? Sitting at the lights 000TPS, IAC is reading 177 - 180. While driving, and 000 TPS the IAC reads 005.

    In the setup the IAC calibration it is in the green / target box.

    The more data I collect the more questions I end up with as I can't seem to understand how these values translate into what should be happening and/or identify if those values are an indication of a problem or an issue?.

    Overall the Ez-EFI is fantastic, I just wish I could get a better understanding of the data values and how to interpret them to obtain the best tuning possible for my engine.

    Thanks.
     
  4. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    I am somewhat disappointed that you did not try a richer air fuel ratio as I suggested. There is a lot of information on the internet that lays claim to air fuel ratios of 15.4 to 15.6 or leaner for best fuel economy but that is primarily applicable to later model stock engines that have been designed to operate with a lean mixture.

    Your engine with the dual quad setup sounds like a performance engine and you probably have a hot cam and other goodies to make it go fast. You may never get really good mileage with it but you should do better than what you are currently getting. One thing for certain you need to try a richer cruise air fuel ratio like 14.1 for a starting point and see what happens to your mileage.

    How much spark advance are you running at light throttle cruise? I run 45 degrees total advance at light throttle cruise and get 18 to 20 mpg with an engine making around 500 hp. You should have 45 to 50 degrees of total advance at light throttle cruise. If fuel mileage is a concern you need vacuum advance on your distributor.

    The air coming in through the PCV valve is not an issue as your engine operates closed loop. The O2 sensor monitors the air fuel ratio and adjusts the amount of fuel being injected to meet the target air fuel ratio.

    Do not worry about the IAC moving around while you are driving as it is doing exactly what it is designed to do. While you are driving the IAC opens up to prevent stalling when you close the throttle. This feature is called the throttle follower and its function is to slowly close the throttle and reduce the idle speed to its target RPM so that the engine will not die.

    It is normal for an engine to make less vacuum at idle than when you start revving it. As the cam gets more aggressive the idle vacuum decreases. My engine idles at 52 kPa and then when I rev it to 1800 rpm the vacuum increases to 26 kPa. Because of your very lean settings for air fuel ratio targets your engine will make less vacuum than it would with a richer mixture. In fact I am surprised your engine will even run with an A/F of 15.9. However your actual A/F is richer than that because your O2 correction is -25% indicating that your ECU has not had sufficient operating time to learn and you actual A/F was richer than the 15.9. In my opinion it is unlikely that your car would be drivable with an A/F ratio of 15.9.

    After your ECU has had time to learn you will see the O2 correction numbers fall in to the range of +- 5% or better. Read the instructions in your help file for Adaptive Learning and it will give you more info on the learning process. +- 25% O2 correction is the maximum that your system can provide and as long as you are seeing numbers like that you have not driven it enough for it to learn. Additionally, every time you make a change your target A/F your system is going to have to relearn.
     
  5. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi Denis,

    Thanks for your reply. With the tests I've done I've made those based on what I'm currently seeing. When I first setup the Ez-EFI (which was mid 2013), I ran it at the stock A/F ratios. Car ran fine but use 42lt / 100km average. I thought that was pretty poor, so I then ran tests at a slightly leaner A/F of 14.7 that got me to 36lt / 100km, so I tried a full lean A/F of 15.9 to see the impact and I got 32lt / 100km. (each test as mentioned above was over numerous tanks of fuel, not just 5 minutes of driving.) I have no problem running another test at A/F 14.1 but as we know it takes time for the system to relearn at that ratio, so it will be a while before I can report back with how the car ran. (Plus I'm currently in the middle of running a PCV test, so I'll finish that first). This car is not my daily driver, so I don't clock up 100's of km's a day in it. If I did that would help speed up the testing process, but it's not practical for me to do. I also mentioned it's been raining for the last few days and this thread is only a couple of days old, so running another test at 14.1 in that time frame in the conditions reported is simply not practical. I also have to work during the week too, so that limits time during that period.

    Spark. I ran the car on a dyno to setup / curve the distributor. Maximum advance I could get without the engine pinging was 34 degrees. Distributor is Mallory Dual point as it is the only one that would fit the Genuine Ford alloy dual low riser manifold and give clearance for the throttle body. If anyone knows of a vacuum distributor that will fit, I'd welcome the information. (I can send photo if necessary). This engine was built in 2000, so maybe a larger range parts are available now.

    PCV. This is the part that I'm not sure about. You mention a closed loop, but the PCV is not. It's drawing air from the valve cover breather into the manifold. The EFI is closed loop but any air entering from the PCV is from outside the closed EFI loop and as the air enters below the throttle body there is no way the EFI sensors can calculate that quantity. It can only go by data returned from the o2, so if air is being drawn in from the PCV the o2 will detect a lean condition and the ECU would add more fuel, but as the PCV induction is not constant the ECU might be constantly adjusting?

    Thanks for the info on the IAC.

    Vacuum. Thanks for info about your engine. That's what I was curious about because that sticky post was focused on idle vs WOT and how that range is not sufficient if you make low vacuum at idle. The irony is, how many cars on the street spend their time from idle to WOT or even at WOT? I know my own driving habits and the roads I drive on and WOT is simply not possible. If driving is primarily spent at up to 20% throttle, then surely the vacuum range to that throttle position should be the key factor as that's where the ECU is spending all its time learning, not where it is at WOT which I rarely achieve. I did read a post (just can't recall the link now) where it mentioned "What you will find is that the more efficient the heads are the leaner you can run the mixtures.". I'm running Edelbrock Performer RPM heads (#6006) that have been worked.

    The -25% o2 correction was when I set the engine back to 14.7 and ran it (that was the first run after switching back from 15.9). When running at 15.9 the actual A/F was 15.9 on the handheld while cruising and the o2 correction was within the +/- 5% correction. By Cruise I mean fixed throttle position (ie 005 TPS) with no change for 1 or more minutes on flat road, then record the reading. (Oh I am at sea level too.)

    No time to learn? I did mention that I ran the car on 7 tanks of gas for each test. That totaled about 1,000 km of driving (per test). How much more is required before you would consider that "enough time". Of course driving distance doesn't cover all the time the car is sitting at lights, or creeping forward in slow traffic, so that would add up to quite a few additional hours of driving.

    What would you consider to be a good distance to run for each test to get accurate and stable averages for fuel economy?

    Regards
     
  6. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    Narler,
    Ok, sounds like you are doing everything right with regard to learning. As long as you are at or getting less O2 correction than +- 5% you are fine. I am surprised that your engine ran well at 15.9 A/F. Mine will not, even at 14.6 A/F with Air Flow Research heads I have serious heat issues and it surges and has poor throttle response. My headers got so hot with a 14.6 A/F that I turned them from a nice silver finish to a dull grey for the first foot or so from the flange. Hard to say how far you have to drive to get the ECU to completely self tune the fuel table because driving habits and road conditions vary so much. I suspect that where you are you can get the critical parts of the table filled in fairly fast as compared to here in the Mountains of Northern California.

    I understand that your engine wants 34 degrees advance at WOT. Mine did not ping but made max power on the dyno at 38 degrees advance. However at light throttle cruise you do need more spark advance to get maximum fuel economy. Do an internet search for "Spark Advance for Fuel Economy", and you will find a wealth of information. Maybe some of the Ford guys on the forum can suggest a distributor with vacuum advance might work on your engine. I got about 3 mpg improvement when I added vacuum advance. I have the FAST XFI, so it was fairly easy to create the equivalent of vacuum advance using the spark table that plots spark advance as a function of engine vacuum and RPM. In one article I read on the internet they claimed that vacuum advance could add a 10 to 30% mileage improvement, depending on engine and vehicle.

    You said,
    "PCV. This is the part that I'm not sure about. You mention a closed loop, but the PCV is not. It's drawing air from the valve cover breather into the manifold. The EFI is closed loop but any air entering from the PCV is from outside the closed EFI loop and as the air enters below the throttle body there is no way the EFI sensors can calculate that quantity. It can only go by data returned from the o2, so if air is being drawn in from the PCV the o2 will detect a lean condition and the ECU would add more fuel, but as the PCV induction is not constant the ECU might be constantly adjusting?"

    Do not worry about air coming into the engine via the PCV valve because it is constant , for a given vacuum the PCV valve will always flow the same amount of air. So, when the engine self tunes and builds the fuel table for your engine it takes manifold vacuum, throttle position, temperature and O2 correction into consideration. Your MAP sensor reads the manifold vacuum and because PCV air flow entering the intake is directly proportional to the vacuum, it is included in the self tuning equation for your engine. Your engine runs closed loop with the O2 sensor always monitoring and correcting the A/F and providing feedback to the ECU for the adaptive learn function. You have real time correction of the air fuel ratio so that actual A/F equals target A/F, regardless of the source of the intake air.
     
  7. sbcregal

    sbcregal New Member

    Joined:
    Mar 1, 2015
    To start with you must understand how an engine works before you can even attempt to tune it. The PCV(Positive crankcase Ventilation) system is closed or you would have a vacuum leak. There is no way to can see the valve open, it is constantly fluttering with very compression stroke, your seeing your butterfly's opening changing vacuum readings. If the PCV valve is not fluttering than replace it. The only way this can affect EFI is if you have excessive blow by. If you remove the PCV you will be asking for oil leaking from every gasket, just a warning.
     
    Last edited: Jan 8, 2016
  8. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Thanks for the replies Denis and sbcregal,

    sbcregal. Yes I'm familiar with what the PCV is and its benefits, but there was never any talk about what impact that had on a self learning efi system and as I'm trying to work out why my system uses so much fuel I thought maybe the the PCV had an influence. For the record my manifold (geniune ford alloy dual / dual plane low riser) has a factory crank case breather at the back of the rear throttle body. A large alloy tube, so the tests I ran with the PCV disconnected would not yield any bad positive crank case pressure.

    If anyone is interested the result. PCV did alter the vacuum. consistent minimum loss was 2 inches hg, maximum varied considerably depending on when it opened. worst reading was a loss of 9 inches hg (but only for a second or two, then stabilized back to the 2 inches hg). Vehicle definitely ran better without PCV, but after recording the handheld values on a dash camera between all the tests, then reviewing them side by side, the end result was what you mentioned Denis. The actual difference while cruising in the hand held values (a/f ratio, load, lb/hr etc) between PCV and without PCV was minimal to the point of insignificant. So now I can rule that out.

    In doing this, something else became evident though, so thought I would attach two pictures from the latest test. A/F target is set at 14.7 (yes sorry Denis, I will do a run at 14.1 soon now that I have finished my existing tests). The current test I have run about 250 km. Image reading-4tps.jpg was taken after 2 minutes of fixed throttle (4% tps), I maintained a constant 4% tps for 5 minutes (level road) and during that whole time the A/F ratio jumped between 13.9 and 15.7, yet what is really strange is the A/F target was showing 14.5, even though it is set to 14.7 and the a/f actual in this image is 15.4. That seems strange when it can clearly reach the 14.7 target due to the actual a/f ratio already being higher than the target, yet it was still taking fuel out with o2 being -2

    Now the curiosity is when you look at reading-0tps.jpg This is after that 5 minutes of constant 4% tps, I slowly reduce that down to 0% tps and the A/F ratio goes to 12.0, the A/F target is now showing 14.7 and the o2 correction is off the scale. The ECU has now dropped out of learning (light is off). So at 0% TPS the engine is using 12 lb/hr of fuel. Just to recap cruising at 4%tps, I just back off the throttle to 3%tps, 02 correction is -11, reduce to 2% tps, o2 correction is -16, reduce to 1% tps and o2 goes to -25 and the ECU drops out of learning (a/f ratio is now 13.3) and now tps at 0% and o2 correction is -28 and A/F ratio is 12.0.

    I can't work that out. Why does it have such a problem when i slowly decelerate?

    This was not an isolated incident. Reviewing the dash camera footage, every time I backed off the throttle it drops out of learning. One incident doing 1,800 rpm at 3%tps and reduced down to 0%tps and the A/F ratio dropped to 11.4 and stayed in the high 11's and low 12's for 20 seconds the whole time I was at 0% tps but the car is still moving, then I pulled up at an intersection where the a/f ratio then jumped to 15.9. While waiting at the intersection the a/f jumped around between 14.1 and 15.7 then the learning light came back on at 14.5, o2 correction was -5, then it when out again, it kept that whole cycle up while sitting there (about 25 seconds). The ECU seems to drop out of learning quite a lot.

    Everything seems so erratic. I can't make any sense out of the values.
     

    Attached Files:

  9. Steiner

    Steiner Member

    Joined:
    Aug 20, 2015
    Location:
    Lyman, SC
    What application is your PCV for? Stock 427FE?

    The way the PCV works is it tries to maintain the same negative crankcase pressure at all loads. It is more closed at light load high vac and opens up with high load low vac.
    -Idle or light load cruise, high engine vac, less chance for blowby, PCV gets sucked closed. This prevents TOO MUCH negative crankcase pressure which can be as bad as blow by without venting.
    -High load, low engine vac, more chance of blowby and crankcase pressure, PCV pintle spring is able to push the valve more open to help create some negative pressure. At wide open throttle you have the greatest chance of crankcase pressure but the least amount of manifold vacuum to deal with evacuating it so the answer is to let the valve crank all the way open.

    Now, because of that action you can imagine that there are a multitude of PCV's because one has to have the right characteristics for the application. For instance, you've got a low idle vac mean cammed 427FE that makes around 7" at idle if I read you right. If the PCV is one for a stock 390FE or 427FE that made say 15" of idle vac then what happens is at idle that PCV on the low vac engine is going to be a lot more open and more of a "vacuum leak" than it should be. That's going to affect your MAP signal and EFI system for sure.

    For low vac situations I've run the PCV spec'ed for the old Chevy solid lifter 302 and 327's as they were some of the lowest vac engines of the time other than the L88. I don't know what the Ford equivalent to this way of picking something would be, maybe the Boss 302?
     
  10. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    Good explanation of the PCV valve and how it operates. I was on another forum and found some additional information about PCV valves that you might find of interest. Here is a link to the info: http://www.nastyz28.com/forum/archive/index.php/t-126001.html

    In addition to finding a PCV valve that comes from an engine with similar vacuum at idle and off idle it would be good to find one from a similar displacement engine. The reason is that at wide open throttle with very low vacuum in the intake the PCV valve may offer some restriction to any blow by that is present if it made for a small cubic inch engine and you are using it on a big one.
     
    Last edited: Jan 26, 2016
  11. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi Steiner and Denis,

    Thanks for the replies. It seems quite challenging to get specifications about PCV's from any of the manufacturers (ie spring rates and operating vacuum ranges). I've been doing a fair bit of research and it looks as if the PCV on my engine is possibly from a Corvette. I used an engine builder that specialises in (and races) Ford FE's and the PCV was supplied with the engine.

    After researching and reading lots since my last post on the forum, I don't think my PCV is either operating correctly, or effectively.

    In my research I did find this company which looks like the best solution. A dual flow adjustable PCV. http://mewagner.com/ It's quite a bit of money to outlay but their website has some good information on it plus they give tuning information based cid and vacuum generated by the engine.

    What I've currently done is purchased 5 different PCV's from Summit and will run some tests with each one (all rated differently, some E's and some F's) to see what variation I notice, plus I chose PCV's from a range of different engines including a boss 302 after reading a heap of other forums and seeing which ones others had success with for low vac engines.

    One new thought I have is I wonder if the injectors are wired up correctly / accurately.. The Ez EFI operates in Bank to Bank and I read this post on the forum http://www.cpgnation.com/forum/threads/fast-classic-b2b-with-seq-harness.21194/#post-77092 which I think confused me a bit more than it helped. If I have 8 injectors and using the default wiring with the supplied splitter harness, I believe it results in 1-1 2-2 3-3 4-4 (as in injector 1 on throttle body 1 is harnessed to injector 1 on throttle body 2). So each bank would be 2 injectors from the two throttle bodies per sequence 1-1-2-2 then 3-3-4-4 is that correct? Or is it 1-1-4-4 then 2-2-3-3, or 1-1-3-3, 2-2-4-4. The reason why I ask that will become clear further down.

    What I'm wondering now though is how effective bank to bank firing is when running a dual plane manifold? I've read another post on the forum (which included a video from Engine Masters) where there was talk that Ez-Efi didn't run well on dual plane in their dyno testing.

    Could this be as a result of specific dual plane designs. Looking here http://www.mustangtek.com/FordIntake.html I see a range of different dual plain manifold designs for ford square bore. Some have 2 oval ports (front/rear), others have 4 circle ports and a couple are like mine which have 2 circle ports and a figure 8 cross over port? (back left to front right) for each 4v.

    From what I can understand the EZ-EFI has no way of identifying the firing order, so how does it know which bank to fire and when, and what is the bank sequence (as referenced a few paragraphs earlier). If the bank sequence fires into the circle ports only and not one of the cross over ports, I wonder what effect that has.

    The manual with the 304155 kit states the throttle bodies can be installed in either position on the manifold. The instructions with the main kit state injector 1 in the throttle body is driver side front (which in reality would be cylinder 7 on my engine). But the issue is that's if it was left hand drive! (pretty annoying orientation descriptions of drivers side / passenger side etc....) . So on right hand drive cars (like mine) I have to set the throttle body around the other way so now injector 1 would actually be on cylinder 4. (throttle linkage is on cylinder 1 side not cylinder 5 side of the engine).

    So should my throttle body be wired so that injector 1 is injector 1 on the throttle body, or is the position of injector 1 in relation to the engine more important, which would mean my injector 1 wire should now be connected to injector 4 on the throttle body? Would that make any difference?

    Also is the default wiring pattern the most optimum for my manifold. I've uploaded an image showing what my manifold looks like and how the throttle bodies are positioned. The main throttle body is at the rear (cylinders 3,4,7,8) and the 304155 throttle body is at the front (cylinders 1,2,5,6).

    I am wondering if a better orientation of the injector wiring would suit my engine better due to the dual plane design (ie the figure 8 port) and the bank 2 bank operation?

    Example if the default wiring references the injectors like this
    1 2
    3 4

    If the bank to bank sequence was 1-4 2-3 then based on my manifold layout that would have the first bank sequence fire into the two circle ports and the second sequence both fire into the figure 8 port. If I repositioned the wiring loom so it was
    1 4
    2 3

    Then it would be firing into 1 circle port and 1 figure 8 port per bank sequence. I don't know enough about the design logic of my manifold and how it differs internally from the other dual plane manifold designs to know what effect it would have.

    For reference in case it is beneficial the firing order of my engine is 15426378

    I have a feeling that the injectors are firing a bank into runners that don't directly feed into a cylinder that's expecting air/fuel. That could be causing the engine to scavenge and may be the cause as to why my readings are so erratic, not to mention possibly wasting fuel.

    A/F readings are never stable, not even at higher rpm. A/F is never constant even sitting on the highway at 3000rpm and a constant 5% TPS, the A/F ratio is so erratic it's almost hard to read and jumps anywhere from 13.5 to 15.5 (in the video I recorded, stepping frame by frame (at 25fps) here are the readings for each frame (so 1/25th of a second for each reading) 14.5 13.5 14.1 14.1 14.3 14.3 14.5 15.5 15.5 15.4 15.4 14.5 15.0 That equates to half a second! Readings were taken after at least 5+ minutes of constant driving at 5%TPS. Is that amount of variation considered normal? Does anyone else experience such a radical shift in A/F ratio in such a short period of time, especially when the engine RPM and throttle remain constant. (well engine rpm variation was +/- 50 rpm over those frames in the video). Many people indicate that changing their A/F target by just .1 or .2 they notice a difference, yet I'm seeing a shift of 2.0 when my target is fixed at 14.7, and rpm / throttle is constant.

    Thanks for any thoughts, suggestions or comments.
     

    Attached Files:

    Last edited: Feb 12, 2016
  12. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    Sounds like you are on the right track with your PCV valve issue. I like the adjustable one but it is definitely rather pricy. If one of the valves you got from Summit is for an engine with a similar vacuum characteristics as yours I would go with it as a lower cost solution.

    I agree that you may have a fuel distribution issue with your setup. However, bank to bank injector firing will always fire some of the injectors into a runner that has a closed valve while others will fire into a runner with an open valve. I am using a Mini Ram intake and with bank to bank injection some cylinders would run lean and othrs rich because of reversion in the intake. With the XFI system I am running sequential port injection and at low RPM the difference is substantial when I use injector retard to time the injectors to the opening of the valves. My engine idles at 650 RPM while the same engine with bank to bank needed to idle at 800 RPM. At wide open throttle there is little difference between bank to bank and sequential. With your setup I do not think the fuel distribution issue is anything you can change even if you rewired the injectors. With bank to bank injector timing there will always be injectors spraying into runners with open valves and others spraying into runners with closed valves.

    With regard to the A/F ratio bouncing around. I had a factory GM Tuned Port system and it did exactly what you are describing. I have an Innovate wide band O2 sensor and an on dash display so I can see in real time exactly what my system is doing. My current XFI system also bounces around even with my VE table tuned well but I have been playing with the closed loop gain which is table driven and have stabelized it some by reducing the gain. The more your system learns how much fuel to add to meet your target A/F the less variation you will see it the swings. Changing the target A/F should have no effect once the system has had ample time to learn.
     
  13. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi Denis,

    Thanks for the reply and the additional info.

    I've still not been able to find any specific information about the bank to bank firing sequence of the Ez-EFI 1 and/or Dual Ez-EFI1, so all I can do is experiment until I find a combination that works best. For now I'll continue to focus on the PCV as I still feel that is causing issues with my system.

    So that I have a constant baseline I'm leaving the A/F set at 14.7 for all tests.

    Currently I've been testing the PCV values I bought and thought I would post the results here in case it is beneficial to anyone else, or if someone has any comments or suggestions as to which one could be more suitable.

    I'll start with the one I'm going to run on the car for a while.

    ACDelco ADO-CV774C PCV Valve, 90 degree, Checker, Buick, Cadillac, Chevy, GMC, Oldsmobile, Pontiac. (Mfr. #: 06487779)
    Attached is a picture showing idle (900rpm) and at 1950rpm. The engine isn't fully warmed up, but the vacuum was the key focus of these tests. In car I run two vacuum gauges. One on the left shows influence on vacuum by PCV and the one on the right show actual manifold vacuum (not PCV influenced). At idle this PCV valve is "scavenging" (not sure if that is the best way to describe it, but it sounds the most accurate) 4 in/Hg, increase the RPM and the PCV closes down, yielding approx 2 in/HG scavenging.

    Here is the values I have worked out for the PCV's I've tested. This is by no means scientific, it's just from reading the gauges (from video recording) to see when they operate and when they vary from the known vacuum.

    ACDelco closes at 9 in/Hg. Below 9 in/Hg it scavenges 4 in/Hg, above 9 in/Hg it scavenges 2 in/Hg

    Fram FRM FV-181 closes at 8 in/Hg. Below 8 in/Hg it scavenges 4 in/Hg, above 8 in/Hg it scavenges 1.5 in/Hg

    Fram FRM FV-191 closes at 10 in/Hg. Below 10 in/Hg it scavenges 2 in/Hg, above 10 in/Hg it scavenges 1 in/Hg

    Fram FRM FV-202 closes at 9 in/Hg. (opens at 8 in/Hg). Below 8 in/Hg it scavenges 4 in/Hg, above 9 in/Hg it scavenges 2 in/Hg

    When I compare these PCV's to my original PCV, that doesn't open or close at all, it just provides a constant 2 in/Hg vacuum loss across the whole range, so either it's not functioning correctly, or it's vacuum operational range is in excess of 15 in/Hg. Either way I feel it is not suitable for my engine.

    Other changes. I'm running a large Morosso Oil Separator on the PCV line to ensure no oil mist enters the manifold. I've replaced tappet cover breathers with new K&N filters, all new 3/8" hoses for vacuum and all new grommets, so there shouldn't be any vacuum leaks.

    I still can't seem to fully understand how the EFI can learn based on vacuum (MAP) and make the judgement that low vacuum = high load. Just looking at the attached picture. Idle, engine makes 8 in/Hg, at 1950rpm engine makes 15 in/Hg. So why doesn't the EFI put more importance on the TPS than on the MAP because light to medium cruising my engine generates more vacuum than it does at idle, so surely throttle position would hold a higher priority than vacuum. From what I can see on my gauges, vacuum isn't a true indication of engine load? (not indicated in the attached picture but as discussed in my previous post), the EFI system always drops out of learning when I lift off the throttle (even if just lifting from 3%TPS to 1%TPS or to 0%TPS). How can the system learn the engine if it keeps dropping out of learning.

    Thanks.
     

    Attached Files:

  14. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    I think you are over simplifying what is happening in the ECU, Manifold vacuum, throttle position, engine RPM, Coolant Temp, Air Temp, fuel pressure, and injector size all play a role in determining how much fuel the ECU will give the engine.. As your engine learns it builds a table that determines how much fuel the engine needs at a given RPM and Load. Attached is the VE table from my FAST XFI system. The table uses vacuum to determine the load, combined with RPM to tell the ECU how much fuel is needed for a given point on the table and then all of the other factors mentioned above come into play in determining exactly how much fuel to inject.

    With regard to the PCV valve, it sounds like you are on the right track.
     

    Attached Files:

  15. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Well, correct me if wrong but it looks like the handheld is showing 100 fuel usage. I'm not that familiar with the new EZ 1 handheld, so that could be normal. If I'm right, this should be a return line fuel system. Be sure that fuel pressure is down to 43 PSI at both the throttle bodies. The fuel lbs. per hour is way off.
    Number two, this intake needs at least 1" open spacers between the throttle bodies and the intake - 2" would be better (fuel reversion with this intake, throttle body injection, and your 106 lobe center large duration cam is overpowering - and I don't trust any of your AF ratios to be correct).
    Number three, the TPS value should be more like .2 since any opening of one throttle body primary supplies twice the amount of primary throttle opening a single TBI would have - idle throttle opening should be equal at each throttle body (.4 TPS would be normal for a one throttle body system at the idle you've set).
    Number four, both throttle bodies fuel injectors should be wired in parallel.
    Number five, don't use a throttle body mounted MAP on this intake system - use the GM single bar style adapted to the manifold vacuum with a rubber vacuum hose, and only use the other sensors from one throttle body.
    Last, but not least, your set idle is too low for the cam you are running. MAP readings and load readings, for your EZ 1 to correctly build fuel maps, should be at least in the low 60's at idle. Raise that idle to get those readings in the low 60's. This will give an immense improvement.

    Once you have this done, do a full reset of the EZ EFI 1. Your readings should become much closer to what they should be showing on the handheld - and your fuel maps should become correct. Your PCV issue should also disappear - and you will be using a PCV for the 390 to 460 FE series Fords.

    EZ 1 ECU operation is very different from XFI ECU controls and what they can do.
     
    Last edited: Feb 28, 2016
  16. Denis

    Denis Member

    Joined:
    Dec 2, 2009
    Location:
    Mendocino County, Northern Calif
    AA, Good point about using a MAP sensor on the manifold rather than the throttle body. I am not sure that I understand your comments about the .2V TPS vs. the .4V TPS. From my understanding the TPS voltage in not what is important because when you go through the TPS calibration procedure you are defining whatever the voltage is with the throttle blades against the stop as 0% throttle and the voltage at wide open throttle as 100%. The TPS voltage at idle with the throttle against the stop and the IAC properly calibrated is going to vary from engine to engine depending on cam, idle speed, engine size and in this case the number of throttle bodies. The thing that concerns me is the fuel distribution in the manifold if the throttle bodies are not balanced and flowing exactly the same amount of air at idle and when the throttle linkage picks up. Additionally, what happens to the fuel distribution when the IAC operates on one of the throttle bodies?
     
  17. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi Denis and AA, Thanks for your replies.

    A A. The new hand held for EZ1 does show fuel pump, but the ECU has no ability to monitor the fuel pump. It can't regulate or monitor fuel pressure, so I'm not exactly sure why they included fuel pump value on the handheld. My system is setup and installed with fuel return line and I monitor the fuel pressure on both lines from in the car. I did include a link to a video in one of my posts (sorry I don't have the link handy).

    Fuel pressure is set using the supplied regulator and is set to 30psi as per the manual's recommendation for dual quad. When you say the lb/hr is way off, what should it be (for an average?). I'm hoping it should be less. If you check most of my posts the one key aspect I keep referencing is the insane amount of fuel the system uses. For example when accelerating, taking a snap shot of the values: At 16% TPS the system reports 58 lb/hour fuel usage. (A/F Target is now showing 13.3 and A/F Ratio is 10.5, yet the system is set to use 14.7), the system has dropped out of learning, MAP is 86, inj DC % is 11, TPS volts is 1.0, Vacuum gauge shows ~ 5 in/Hg. Now if I stay on the throttle a second or two longer and reach 31% TPS, the system reports 106 lb/hour fuel usage and inj DC % is 21. Vacuum gauge shows ~4 in/Hg. The car is moving pretty quick now though and the rear tyres are struggling, so it's not as if it isn't putting that fuel to good use, but it's a heck of a lot of fuel.

    2) I don't have the bonnet clearance for large spacers. I am running a 1/2" ported phenolic spacer. The AF target never seems to stay set. Even in the last picture you can see between the two tests it's 14.6 on one and 14.7 on the other (taken less than 20 seconds apart). Yet I set it to 14.7, so I really don't understand why the system doesn't honor the settings. Sometimes while just cruising the A/F Target will show 14.0 ! Under acceleration it could report anything (as listed in the above paragraph). Either this new handheld is rubbish for accuracy (the battery volts is wrong to begin with), or there's something else going on causing it to report crazy numbers and high fuel usage.

    3) Dual Quad setup only has one TPS, one IAC, one MAP on the main body. The second throttle body appears to be dumb with no sensors on it at all. It doesn't even have a vacuum port! I spent quite a bit of time to ensure the opening of both throttle bodies was as close and as accurate and balanced as I could get to ensure there was no A/F ratio differences between the two bodies (ie if one was opening slightly earlier that would draw in more air etc.) I've also utilized the services of some senior mechanics I know to check it as I was aware of how much impact that could have.

    4) The injectors are wired using the supplied splitter harness, so Body A injector 1 is wired with Body B injector 1; Body A injector 2 is wired with Body B injector 2. etc... Injector position is considered to be: cylinder 7 (inj 1), cylinder 3 (inj 2), cylinder 8 (inj 3), cylinder 4 (inj 4). That is for the main throttle body. The dual quad throttle body: cylinder 5 (inj 1), cylinder 1 (inj 2), cylinder 6 (inj 3), cylinder 2 (inj 4). There is not enough clearance to put the main throttle body at the front. It doesn't clear the distributor. The manual stated it didn't matter which position they were in (1st or 2nd) and I only had one option anyway.

    5) I've never heard of this part before. The system only has 1 MAP and that's on the primary throttle body. What I didn't like about the system as is, which could be playing a part, is I connected a vacuum gauge to a non ported vacuum outlet on the primary throttle body and the gauge nearly shook itself to pieces because it's only reading 4 of the 8 cylinders. If it's this bad for a mechanical gauge, how does the ECU cope with such radical fluctuation? Maybe it isn't? Is this the main reason why you recommend not using the Throttle Body mounted one? Because the TB mounted MAP can really only reference 4 of the 8 cylinders?

    Is this the item you are referring to http://www.fuelairspark.com/fas/1-bar-map-sensor-ls1-stylehtml/

    Or is it this one (this looks like it has a more traditional barb hose fitting). If this one is what you mean and/or is ok #307007, then I'll look at ordering one.

    http://www.fuelairspark.com/fas/1-bar-map-sensorhtml/

    6) Idle. I'll increase the idle and see how it goes.

    I thought the Ez EFI was suppose to have a "limp" mode so that if you drop a sensor it will keep you running? I wanted to check how the system coped with no MAP so I disconnected it. The ECU refused to start the car. Engine would just crank and never fire. Connect the MAP back up clear the error and bingo fired straight up. That was a bit concerning.

    If I use the #307007 MAP instead, is there a "bung" or something I can place in the TB mounted MAP so the plug doesn't get crap in it? What's the name of the fitting it uses?

    Thanks for all your input and suggestions I'll look at implementing them and report back once I'm able.
     
    Last edited: Feb 28, 2016
  18. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Guys, the data acquisition you are doing is good - but you are overlooking the obvious with all the details. This engine has a severe fuel reversion problem due to the intake design and the camshaft used with it. Just looking at the intake flange I can see the problem - it was specifically designed for carburetor venturi performance. From the supplied user data, the MAP sensor is dying or being corrupted with broken pieces of its seal in the throttle body, i.e. corrupted vacuum signal from all the fuel reversion going on (and no telling what kind of crazy vortices under/in the throttle bodies). The added user info further points this out.

    Because of the fueling issues due to this dual plane intake and the cam used, the EZ 1 ECU cannot build correct fuel maps. Currently, the high MAP readings are making adaptive learning impossible. This engine needs idle and cruise ratios in the 13.0-13.7 F/A range, but the fueling is so corrupted it requires otherwise. If not repaired, severe engine damage is going to occur - if some valve damage hasn't occurred already.

    This engine needs a single plane intake without any doubt - one to two inch open spacers are just a stop gap measure in an attempt to use the dual plane with TBI. There would also be a huge benefit using a camshaft actually using some numbers tailored for fuel injection. For now, the MAP sensor needs to be replaced with FAST adapter #308031 and FAST MAP #307007. The replacement MAP may allow some of the adaptive learning to start again, If the MAP reading is lowered enough, but it won't repair the main issues with the intake that is being used or the current camshaft.

    Limp Mode

    "I thought the Ez EFI was suppose to have a "limp" mode so that if you drop a sensor it will keep you running?"

    Limp mode only occurs when the MAP sensor has completely failed. The reading will be 65 when the sensor is completely failed with the key on and the engine off. Disconnecting the MAP will prevent injector firing.

    TBI MAP Replacement

    You just use the original TBI MAP to seal the TBI MAP port. It won't matter if anything enters it since you will be using a manifold vacuum port with the new #307007 MAP.

    Narler, your additional info again confirms the MAP, intake, and cam problems. It sounds like you have the other issues covered. A higher idle will help, and the TBI throttles must be balanced as Dennis and I have stated.
     
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014

    Dennis the .2 - .4 TPS just pointed out the amount of throttle opening being used for this engine to idle. It is excessive even in relation to the more normal looking IAC reading - if the primary throttle positions are the same.

    IAC only used at one TBI in a dual TBI system is nominal and should not adversely affect idle in normal circumstances. With this intake it is a problem.
     
    Last edited: Feb 28, 2016
  20. Narler

    Narler New Member

    Joined:
    Jul 17, 2013
    Location:
    Australia
    Hi A A,

    Thanks for the reply and additional information.

    To recap those parts first. I couldn't find #308031 on the FAST website, but it is listed on Summit (no pictures though). http://www.summitracing.com/int/parts/fst-308031

    I'm not sure what it looks like. There is a #308029 listed on FAST website http://www.fuelairspark.com/fas/map-sensor-adapter-harness-early-to-late-gmhtml/ Is this an indication of what #308031 would look like?

    So just to get it clear in my head (as I have not found a picture of the #308031). Disconnect MAP from TBI, plug #308031 into that MAP plug (from harness), connect other end into new #307007 MAP, Mount #307007 somewhere, connect vacuum line from manifold to #307007. My manifold only has 3/8" vacuum lines. The details for 307007 don't mention hose size, but it looks pretty small in the picture.

    This would then leave the MAP plug on the TBI open / unused. You mention to use the original TBI MAP to seal? I'm not visualising that? I have the MAP female on the TBI and I have the MAP Male in the harness, I assume MAP Male goes into #308031 (or possibly directly into #307007 which is female), leaving nothing to seal TBI MAP female? Or does #308031 have a dummy MAP male on it as well?

    Would the MAP Male plug from the harness plug directly into #307007, or does it use a different connector, hence the need for #308031?

    I just want to double check, so that I order everything I need. including probably stepping down from 3/8" to maybe 5/16". If manufacturers could list all specs for parts that would be helpful.

    "Just looking at the intake flange I can see the problem - it was specifically designed for carburetor venturi performance."
    "This engine needs a single plane intake without any doubt"
    "There would also be a huge benefit using a camshaft actually using some numbers tailored for fuel injection."


    All those three points you mentioned are good ones and clearly very relevant, however the part which bugs me the most is the clear fact that the Ez-EFI was advertised and marketed as a direct Carburetor replacement. The brochure I got when I first started researching parts in 2012, before I purchased, I'm looking at right now and it clearly states :

    "Works on your Engine - No Manifold or Extra Parts Needed

    Regardless of your brand or size, this system bolts on easily to any carbureted engine making up to 650 HP – NO manifold replacement is needed. In addition to matching any carbureted manifold, the EZ-EFI Self Tuning Fuel Injection...


    The next paragraph in the brochure states this:

    An EZ Solution For Any Setup.
    For more aggressive applications, the EZ-EFI Dual Quad Upgrade Kit is capable of supporting 1200+ horsepower engines with dual quad carburetor type manifolds.


    Now I know there have been a whole load of engine designs over the years, but the way it is worded in their brochure is pretty blatant. "regardless" and "any" and "NO".

    So it's clearly disappointing to spend all this money and find out that it's simply not true and/or I've been completely misled. If I wanted to replace manifolds and cams I would have gone for a completely different setup and not use TBI at all, even though my engine does have a geniune ford dual plane 8V alloy manifold.

    I'll double measure the amount of clearance I have to the hood and see if I can get away with a 1" open phenolic spacer and give that a try. I thought having an open spacer on this style of manifold (4 round ports) would cause interference as it would leave edges to interfere with the mixture? (eg. mixture leaves the TBI which itself is square bore, enters into the open spacer void then collides with the top sharp edges of the manifold as it tries to enter a runner?)

    Thanks
     

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