Welcome to CPGNation.com! Log in or Sign up to interact with the CPGNation community.

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
    This confirms what I suspected- I went up too fast on the idle AF. I'll set it to 13.6, enrichment at 0 and try again.
     
  2. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    You'll want to pay attention to what idle A/F does to both cold and warm engine cranking. Cold engine cranking will likely be the most noticeable as you lean A/F, and is especially so with high overlap cams (which shouldn't be a problem with your cam). The right idle A/F will make the initial cold cranking RPMs stabilize more quickly to the ECU set cold start RPM. The bad thing is you only get about one shot at this a day - only after the engine has cooled completely and any remaining fuel has evaporated from the intake. I set cold start after seeing how the engine cold starts over a number of days while watching the RPMs closely at start.

    You want to achieve a balance using the idle A/F first, and then the handheld start enrichment, for best cold and warm start cranking. You'll see a pattern emerge.

    It wouldn't be this difficult, but the ECU uses the warm engine set A/F maps to adjust its internal cranking maps (adding or subtracting from the initial cranking fuel squirt). So, the ECU has to learn each new warm A/F. Go slow, and you should hit optimum settings in a few days time. The color handheld only "fine tunes" the initial ECU crank settings.
     
  3. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Here's an added piece of information on cold start. When you do the cold start, let it idle and shut the engine off before it warms more than a minute or two - and check a few plugs right away. If you see any raw fuel on them, lean the idle A/F another tenth until you see no more raw fuel. The cold start should continue to be easy - maybe even better. I found one of my engines liked 14.3 sitting at warm idle in gear and didn't show any signs of gas fouling with cold start at 14.3 with zero crank enrichment. I then set the start enrichment for best warm starts. Before I did it this way, the engine appeared to like a much richer idle A/F.
     
  4. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Been a while and I've been busy with other things but now I have something to report on the ignition issue.

    Over the 4th Holiday my son was here visiting and we hooked up the oscilloscope, first on the coil wire. We determined that the Second Spark unit does nothing. Set at 1,2,3, or any number up to 9 registers the same on the scope and setting to zero, which the manufacturer states turns the second strike off. Disconnected the engine does not run so it is basically a very expensive tach signal for the EFI unit.

    The shape of the signal is consistent and basically text book. It's more of a buzz than a snap, meaning that the spark is fairly long in duration.

    Next we read each spark plug wire. I found out that I was getting stray signals from the adjoining leads, per the firing order. My theory is that the signals are getting picked up inside the cap, causing misfires and possibly cylinders working against each other. This is a small diameter cap, not a large diameter as per later years when high energy ignitions were introduced. Apparently the reason why the more modern caps are bigger is to space out the rotor contacts for less interference.

    I did screen shots of each so can post if anyone's interested.

    So I bought an OE replacement coil. I haven't scoped it but it should be around 10k volts instead of 45k. Anyway, the car runs a lt better. Still not perfect (probably the cam). But a lot smoother, quieter.
     
  5. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
  6. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Thanks, I read that thread before I saw your post. My firmware version is 2.37 with tune 005. I'm unsure if 2.37 makes a difference here.

    Two weeks ago I contacted Pertonix by phone and Fank Van Es was stumped, said he'd discuss with engineering then got back to me by email. Engineering was confused about all the cross talk in my scope traces, and they suggested that I install a new set of plugs, new cap and rotor. So I did that, took a photo of my old plugs lined up from the driver's view (next to two new ones). Then I did more scope traces. This is a link to a google drive so you can see the full resolution photograph and traces. https://drive.google.com/open?id=0BybYBHsfnIw_V0UwckhsMDFXd1E

    For these scope runs I figured out that I needed to shield the bare metal sensor clamp, because that seems to be the cause of the cross-talk. Here's what the clamp looks like: https://ae01.alicdn.com/kf/HTB12768...0000-pico-scope-FREE-SHIPPING.jpg_640x640.jpg.

    So to make a shield I cut the top and bottom off of a Coke can, insulated the interior with duct tape, positioned it over the clamp, used a test wire to ground it, and lo and behold it removed most of the cross talk. The Google drive link above has pdfs of each cylinder (bottom blue) along with the coil wire (top purple).

    The cylinder 1 trace is fairly representative so I'll post the picture here then comment further in the next post.

    cyl1_001.jpg
     
    Last edited: Aug 7, 2017
  7. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    The trace in my last post shows three complete spark cycles. Note that the spike from the 4th pulse after cylinder #1 (from #6) causes a spike in #1. The #1 wire routes between the #2 and #6 posts so it looks to be getting some pulse from that if #6 has a big spike like shown. Since it's 180 degrees off though that would have no effect on performance. More of concern is why #6 spiked like that.

    The other issue with this trace, and this is consistent with all cylinders, is the sloping shape after the spike on the individual cylinder. I emailed this to Frank and asked him to respond about that specifically. It's been a week and no response.

    Research that I have done points to high resistance in the circuit. That, along with the loss of energy between the coil trace and cylinder trace (note the different scales so the cylinder traces shows up), this is leading me back to the large gap between the rotor and cap. This may also explain why Pertronix is choosing to ignore me.

    In any event, I'm using the excuse of my 58th birthday to buy myself a new ignition system. Last night I ordered from Jegs, a new MSD Ready to Run Distributor, part number 8595. It has a separate tach signal wire (square wave) that I hope to use for the EFI, since I plan on eliminating the Petronix Second Strike box altogether. In that same order I have a new bronze distributor gear, in case my old one doesn't fit for some reason, a new blaster 3 coil, in case my OE type coil isn't working well with the new distributor, and a new MSD 6A box, in case the distributor tach signal does not work with the EFI. As you can see, I have little patience with trying something, then waiting for a delivery to try again sort of thing. What I plan to do is take a day off from work, remove all the old Pertonix stuff, try the new distributor by itself then work upwards from there all on the same day. Any box that I don't need to open I'll send back.
     
    Last edited: Aug 7, 2017
  8. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    I would make a point of having FAST reflash that ECU to 2.38 005. It's possible you have an issue with the Pertronix, but you've spent a small fortune trying to get your FAST EZ EFI 1.0 system perfect. Sure, you've corrected a lot of problems, but to find out the ECU firmware could now be one of them is outrageous. I don't want to see you have any more problems. You have really worked hard and deserve better.

    Some people seem having bad experiences with the MSD 8595. If you go with it, be sure to use the # 84211 phasing rotor.
     
  9. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I don't see how the EFI firmware could cause the spark trace to behave like that.

    This is the first I've heard of a phasing rotor. Why isn't one available with the Pertronix? Maybe that's what is causing the issue.

    By the way I forgot to say in my earlier posts that I had gone through all of the voltage and resistance tests that Pertronix has published. For instance they want less than 0.2 ohms between the distributor plate and the battery negative. Mine was 2.0. Some of that was in the battery post and ground connections, already clean and tight now even more so, but I eventually found 1.0 ohms in the new battery negale cable itself. I ran a new ground and got the required resistance down to 0. No change.

    Then Pertonix asked me to run a new ground from each head then to the battery. Done. No change.
     
  10. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Yes, the ECU software can cause those erratic spikes - by changes in fueling. Fueling, compression, and timing all affect the spark.

    You mentioned using the MSD distributor tach wire - best to leave that as it was designed for in RPM limiting. I believe I remember you also have a FAST ignition box - it gives a good square wave signal for the ECU, so do MSD ignition boxes. With the Pertronix distributor and Second Strike removed, I would put the FAST Hi6 or a MSD 6A in use.

    The phasing rotor may not be needed with the MSD 8595. It's usefulness increases depending on how much mechanical advance you have dialed in and where the rotor is in relation to the pickup and paddle position. Mechanical advance also affects where the rotor stays in relation to the cap contacts. It becomes very useful with locked rotor distributors such as I run with my EZ 2.0 systems. You'll be able to increase your initial timing much more with the MSD than the Pertronix allowed. The vacuum advance will also offer even more adjustment. Depending on design, vacuum advance can also affect rotor phasing.
     
  11. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    As far as the ECU causing the spikes, maybe. I don't want to wait 3-4 weeks during peak cruise-in season to ship it to and back from FAST. I'll wait until winter to do that.

    Besides, the roughness has always been there, and again the EFI doesn't explain the slope of the trace after the initial voltage spike. The only thing that would cause that is high resistance in the circuit. The large rotor gap explains that. I also has a Pertonix carbon button (center of the cap) disintegrate so maybe their manufacturing of that portion of the circuit is problematic. An out-of-phase rotor would as well, if it is occurring at zero mechanical advance. With that in mind I'm going to drill a view hole in the Pertonix cap and see if that is occurring.

    I found this video that helped me to understand what the phasing issue is all about and how to properly adjust the MSD rotor.
     
    Last edited: Aug 8, 2017
  12. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Regarding the MSD distributor PN 8595 tach wire, the install instructions describe the signal as a 12V square wave with a 20% duty cycle to provide "a clean tach signal to most tachometers and even some aftermarket fuel injection systems." The distributor is designed to be used without an ignition box, but will not provide a multiple spark. I'll be ding this install first without the box; we'll see if it works with the FAST EZ EFI 1.0 or not.
     
  13. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    Here's the video of the Pertronix distributor with an access hole cut into the cap next to the #1 cylinder. It appears that I've found the culprit.
     
  14. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    Good luck with the project. When you use the phasing rotor, be sure to tighten the adjustment locking screws using some Loctite. They aren't a snug fit and tend to come loose otherwise.
     
  15. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I installed the MSD distributor and removed the Second Strike box and the engine ran better. The distributor tach signal works with the FAST EFI. I then drilled a view hole in the cap and did the same exercise as my video in post 213. The non-adjustable rotor is phased properly at 18 degrees initial, and throughout the 18 degree mechanical advance.

    I then added the MSD Digital 6A box and then took a video of the spark pattern through the view hole. You can basically see all 12 strikes at idle. Plus, the sparks look hotter than with the distributor alone.

     
  16. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    I changed the rotor and cap then took a second test drive. First of all there is a noticeable improvement in starting with the box. The car runs better too.

    Next I switched the tach feed to the EFI from the distributor to the 6A box. Again an improvement. I was able to lower the idle speed from 750 to 675, and the idle AF from 13.8 to 14.2.

    Then I took a long drive, to three cruise-ins, basically about 120 miles. I'm still getting some roughness, but only a certain RPMs. I'm thinking that it may be the vacuum advance. It is connected to the high port of throttle body, per MSDs instructions. The vacuum advance curve is 1 degree at 6 inches of vacuum, linear to 16 degrees at 12 inches of vacuum. That seems pretty aggressive. I think that I'll disconnect the vacuum advance and see if the roughness goes away.

    No improvement in fuel mileage, still at 12 mpg.

    One thing I noticed during my long drive, not sure if it was like this with the distributor tach signal, but the rpm reading on my hand held (dash mount) is much more steady. The digital readout would always "hunt" for the number before, now it is steady.
     
  17. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    This all is a lot like I expected. There may be some slight adjustments needed for the timing as you noted (vacuum and mechanical). You've got everything you need now, including the knowledge, to get this focused. That roughness may also disappear with the ECU update, but be sure to get the timing all set first. After the ECU update, you may be able to lean the mixtures for better mileage.

    I can hear the difference in the two videos of your engine - less clatter in the MSD video.:)
     
    Yadkin likes this.
  18. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    After I got the ignition quieted down I found a slight exhaust leak in the passenger side head to header connection, cylinder 4. I know it wasn't leaking previously, so must have developed by pushing out a tiny bit of sealant sometime in the last 1000 miles or so. In any event, a slight pt pt pt sound, and I could feel the escaping gas when I put my hand close.

    With every gas escape there will be a corresponding fresh air in, and this causes the O2 sensor to see higher level of oxygen, which the ECU sees as a false lean. This explains my poor fuel mileage.

    Fixing involves raising the engine off its mounts, partially removing the headers (normally I only have about 1/8" clearance to the chassis), cleaning with snapper of a thin metal strip, solvent cleaning ten painstakingly applying a thin coat of RTV copper. Back on, finger tight, 24 hour cure, then torque down as tight as I could and still leaking, now two small areas. So I threw a hail Mary and squeezed in more RTV over the top and let that cure- holding for now.

    I drove the car twice today and it was noticeably smoother. So much so that my wife noticed it.
     
  19. A A

    A A Well-Known Member

    Joined:
    Jun 22, 2014
    If you have tube headers, you need to find a header specialty shop. They could modify your header to easily fix this by allowing the use of a standard exhaust gasket.

    If you have the factory cast exhaust manifolds, a machine shop can mill the header to stop the leak.

    Might be worthwhile checking into.

    At any rate, a ceramic header coating makes a better gasket.

    This one is good - http://www.virginiavettes.com/hot-stuff-manifold-dressing.html
     
    Last edited: Aug 25, 2017
  20. Yadkin

    Yadkin Member

    Joined:
    Jul 22, 2013
    Location:
    Yadkin Valley, NC
    These are Sanderson headers. They recommend using no more than a smear of RTV copper. I'm using a bit more than that. And honestly I don't think I have room for a gasket since the clearance on both sides is so tight. Thanks for the tip on using a header coating. If it leaks again I'll try that.
     

Share This Page