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Rough running EZ EFI 1.0

Discussion in 'FAST Support Forum' started by Yadkin, Aug 23, 2016.

  1. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I installed my new fuel sytem and EZ EFI about 6 months ago. I've had other engine issues in the interim but have that all ironed out and am focusing now on fine tuning. This is a 64 TBird with a rebuilt 390. Decked, balanced. Lunati hydraulic roller cam and lifter set, mild lift and duration for best idle and low end torque. Compression ratio is 9.7:1 and I use premium gas. PQ adjustable roller rockers. My goal is smooth operation, easy starts, good fuel economy.

    The engine starts a little hard when cold, a little worse when warm. Idle is good but not perfect. Power is good. No knocks at all. The biggest problem is that cruising power is not smooth. It feels like an ignition issue but I have done everything that I could to tune that. My best description is that it feels like one or more of the cylinders are not firing completely. Fuel mileage is terrible- around 8 or 9 and I should get around 16.

    The ignition is a FAST E6/ E92 with a new Pertronix distributor. Ignition timing is 16 BTDC initial, increases to 34 between 1500-3400 RPM. I have the vacuum advance connected to the throttle body above the throttle plates. I double-checked all the E6 wiring so that it is exactly per the instructions. Large red directly to the battery- no fuse. Large black directly to the block ground. FAST recommends consider grounding both heads to the block, and I have all ARP engine bolts so was concerned about this, but I measure zero resistance between the block and heads. Spark plugs are Autocraft copper, brand new, gap set to 0.039. Wires are MSD Street Fire.

    Note- Earlier I had a set of Autolite plugs and Taylor Street Thunder wires and the car ran terrible. The wire boots were too long on the plugs and it was difficult to get a "snap" when installing. I trimmed the length of the boots and that made the assembly only marginally better. After a 100 mile run I found #8 plug black and #3 broken insulator. I gave up on that combination completely for the Autocraft / MSD combination and the connector fit to the plugs are much better.

    I also double checked the wiring on the EZ EFI 1.0. Red is to the battery + post, fused. Black to the battery - post. My fuel system consists of a Tanks Inc pump inside the gas tank. Tank is vented. I have an Aeromotive AFS 12308 filter and AFS 13129 bypass pressure regulator set at 43 psi. 3/8" steel supply and 1/4" steel return. Hose connections are all 3/8" Russell hose and AN connectors.

    When I turn the engine off the fuel pressure immediately leaks down to zero. I suspected that I might have some crud keeping an injector open so I replaced all four. When I did, I inspected the fittings in the throttle body carefully and found that the casting was porous. I'm not sure if this is the problem or not- I suspect not. Pictures of each 4 are attached.

    LFc.jpg LRc.jpg RFc.jpg RRc.jpg
     
    Last edited: Aug 23, 2016
  2. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    My local mechanic suggest that my original cast iron intake manifold may be the culprit. It was designed for a four barrel carburetor with vacuum secondaries. At cruise only the two front barrells would be operating but with the EFI all four are. I don't know if this is the problem or not.
     
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    The factory intake is a dual plane. Switching to a single plane intake will make a world of difference with throttle body injection - as will running the correct heat range sparkplug with the single plane intake.
     
  4. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Seriously? What manifold would you recommend for this application so I don't have to cut a hole in my hood? Remember that this is a big heavy car that I want to idle and run smoothly with good economy. The engine will rarely see 3500 RPM
     
    Last edited: Aug 23, 2016
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Seriously. Everyone is experiencing much improved all around performance and increased power from idle up using the single plane. The dual plane works great with a carburetor for its different fuel metering characteristics. But, the dual plane does not work well with TBI systems - even for those who thought it was. I'm one of those who found out after running a dual plane that seemed fine and made good power - for over a year in my TA. Swapping to a Victor Jr. made a dramatic difference for the better throughout the entire power band in my TA - and I was also able to lower my idle from 950 to 750 (with my XE hydraulic roller), after a more efficient tune the dual plane would never allow. Fuel distribution using a single plane dramatically improves fuel distribution to all cylinders.

    Any single plane intake you can find for your 390 will be a big improvement. You'll have to look around to find one with a low rise that fits your vehicle. You can ignore the suggested power band for the single plane intakes when using TBI. Deeper single plane intake plenums also improve performance for engines experiencing fuel reversion.
     
    Last edited: Aug 23, 2016
  6. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
  7. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    What if I disconnected the rear throttle linkage along with the two rear injector connections? Basically running a two barrel set up. Could I expect smooth running at idle and cruise?
     
  8. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Well, it does bolt on easily, and supports up to 650 HP - even with a dual plane. The issue concerning dual plane intakes wasn't realized until later. Some mask the problem better than others.

    "What if I disconnected the rear throttle linkage along with the two rear injector connections? Basically running a two barrel set up. Could I expect smooth running at idle and cruise?"

    Nope.

    Short of changing the intake to a single plane, there is always the handheld upgrade option. The new handheld provides more fuel options for starting. Unfortunately, a single plane intake is still needed to have best performance.

    http://www.fuelairspark.com/fas/fas...pgrades-first-generation-ez-efir-systemshtml/
     
  9. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    "The issue concerning dual plane intakes wasn't realized until later."

    "NO manifold replacement is needed." Is from the current website.

    I need to fix this. I've spent a lot of time and money and not received what was promised. Will the manufacturer work with me to trade in parts of my current system for a cost effective upgrade? Remember that my throttle body casting is porous- pictures above prove that.

    Looking at their online catalog, I assume that I'm going to need an intake manifold 303390 under a throttle body 307603. The manifold gives me 8 injector ports (I have 8 injectors). The body has a TPS and IAC (which I already have, so don't need). Not sure where to mount my air temperature and MAP sensor (does the manifold have ports?) and of course my ECU, O2 sensor and all the wiring is all neatly installed so I'd like to leave as is. Can I splice in wiring for the extra injectors, one each on the four existing wires (black-yellow-green-brown)?

    I think it reasonable that I purchase the manifold, and trade in my stripped throttle body for the new one. I need to know heights of each though because that's not described on their site.
     
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I'm not a FAST employee. I can't say what FAST will do. You need to discuss all of this with them on their tech line.
     
  11. RussellB

    RussellB Member

    Joined:
    May 28, 2016
    Swapping from dual plane to single will make a difference, check your plugs - good chance 4 of them are off. When i had dual plane it "worked" but not as good as when i changed it over for a single plane.

    Yes its annoying, yes you shouldn't have to do it, but it does make it run better.
     
  12. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    What manifold did you swap out?
     
  13. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I just sent Tech a long email describing the problem and asking for a solution. Thanks for your help.
     
  14. RussellB

    RussellB Member

    Joined:
    May 28, 2016
    I swapped a factory 4 barrel for a Weiland Xcellerator, my engine is a 302 Cleveland. I did not go port injection as you are proposing.
     
  15. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    They don't make one for a big block Ford.

    Still waiting on tech support to answer my email. I'll probably have to call them and read it to them.
     
  16. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Tech support got back to me and made two suggestions.
    1. An aftermarket single plane manifold, or try a simple 1" open spacer.
    2. Don't use the vacuum advance.

    My current (original) spacer is a four-hole wedge, 1-3/8" at the front and 7/8" at the back, water cooled. I have a Moroso wedge plus a Jegs 1/2" phenolic on order, both square bore. I'll try that first before changing out the intake. An Edelbrock Victor is $700 and 6.5" tall. I'm almost certain that it will give me hood clearance issues.

    Easy enough to plug the vacuum.
     
  17. CWPottenger

    CWPottenger Member

    Joined:
    Nov 25, 2014
    As far as your pressure leak down when off, this is normal for aftermarket EFI bypass regulators. Not an issue as long as it holds pressure across operating range when engine/ pump on. OEM regulators must hold pressure when off due to emission regulations

    The gains and losses of single vs dual plane vary greatly depending on the combination of parts. I also changed from dual to single not because I had any real issues, but because everything I read and was told that TBI EFI just prefers single. I have had some minor improvements mostly in lower idle and a decrease idle temperature(probably due to lower idle rpm's) and allowed me to lower my idle AFR slightly. As for power I have not had it on a dyno before or after switch, but honestly it doesn't feel different(but again not scientific answers).

    The 1" open spacer will make a difference by reducing the "dual plane effect" felt by the TBI.
     
    Yadkin likes this.
  18. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Offenhauser makes single plane models for less, but you will need to check it is the 4150 base style - Offy 5774 " Equa Flow 360"

    Port O Sonic https://www.summitracing.com/parts/ofy-6148/overview/make/ford - for Quadrajet, will require an adapter to 4150

    With Offy, you have to be careful not to get the 4500 carb base or you will need to find an adapter to 4150.
    Offy 5960 dominator intake
     
    Last edited: Aug 29, 2016
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Sorry to hear you haven't noticed a larger difference. At least your statement does show something you haven't realized. Being able to lower your idle further relates to marked improvement in low RPM fueling. What happened was the improved cylinder fueling increased low RPM torque which allowed the lower idle. The lower engine temp just confirms you have better cylinder fueling now. This also allowed the leaner mixture you referred to - without increasing engine temp. All of this points to you're now having better fuel mileage - even if only slightly better. With every thing dialed in, your track ET should improve .1 to .2 or better in the quarter. On the track is where you will see the improvement in numbers. (Scientifically);)
     
  20. RussellB

    RussellB Member

    Joined:
    May 28, 2016
    Let me know how much difference unplugging the vac advance has - mine is still connected up for now to manifold vac, should try with it disconnected too i guess..
     

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