Starting problems - Gen3 conversion.

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PostPosted: Thu May 24, 2018 9:18 am
New issues - still trying to make BIR this weekend. Long post follows.....

Car finally started after several attempts. When it started, it idled at 2500 RPM so we killed it right away. Tried to start again and it wouldn't fire. Cycled power several times and got it to run again - all pressures looked good and the motor got warm but it was idling high and "surging" while idling. Shut it off after a couple of minutes. Tried to start again a few times - turns over just fine - but it would't fire. After a few more tries it would start, but one time it stopped on it's own. Now it won't start/fire at all.

Notes -

-It only starts/runs when the fuel pump cycles at power up. If the pump does not cycle at power up, it won't start.
-The fuel pump does not cycle every time at power up. However, the fuel pump runs EVERY time the manual button button is pressed.
-Manually running the fuel pump while cranking does not help
-There is no spark when the pump fails to cycle at power up.
-Swapping relays did not help
-When it runs, it idles high and surges a few hundred RPM

Other notes:

-Gen3 kit used for conversion is 1.5-2 years old. Kit was purchased with a Gen2 car.
-Fuel system build pressure just fine when manual button is pressed.
-The ECU light is steady (not flashing)
-Don't know much about the ECU software, but on a diagnostic page I could find no sensor errors (need to investigate further)
-The TPS has been calibrated.
-After I bought the car late last year, I had issues where the car would run for 10 minutes then sputter then die. At the end of the weekend it would not start at all.
-I used no Gen2 harnesses - I bought a Gen3 chassis harness. The only carryover Gen2 parts that I can think of are the fuel pump, master switch and throttle body/TPS.

Any ideas are welcome.

Ron
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PostPosted: Thu May 24, 2018 11:38 am
One of our common problems with our Gen3 conversions is the IAC valve located on the top of the throttle body. NAPA part no. 28940 or Echline 2-20238. Switch that out. You possibly will need a CSR on the phone to help you calibrate it. That part was a non issue on our Gen2's. Bad or non existent idle is symptomatic of that part of our throttle body.
The surging you experienced as it warms up is normal. RPM's cycle up and down. Weird part of our warmup on Gen3.
I am assuming you setup the fuel pressure correctly without the engine running. You need pressure assured at the fuel rail before starting.
Another note is to make sure you are up to date on the version of your ECU. Since your kit is several years old, you might have an older version. (v37?) I think is correct. Again, a CSR can walk you through downloading it into your ECU.

I am sure more help is coming here! Good luck!
Mark Fick

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PostPosted: Thu May 24, 2018 2:47 pm
markfick wrote:One of our common problems with our Gen3 conversions is the IAC valve located on the top of the throttle body. NAPA part no. 28940 or Echline 2-20238. Switch that out. You possibly will need a CSR on the phone to help you calibrate it. That part was a non issue on our Gen2's. Bad or non existent idle is symptomatic of that part of our throttle body.
The surging you experienced as it warms up is normal. RPM's cycle up and down. Weird part of our warmup on Gen3.
I am assuming you setup the fuel pressure correctly without the engine running. You need pressure assured at the fuel rail before starting.
Another note is to make sure you are up to date on the version of your ECU. Since your kit is several years old, you might have an older version. (v37?) I think is correct. Again, a CSR can walk you through downloading it into your ECU.

I am sure more help is coming here! Good luck!


Thanks a ton Mark - I'll check the IAC out. Hopefully that takes care of the idle when the car starts. Problem now is - it won;t start at all. When it did start, the fuel pump would cycle for 6 seconds first.
I think it's supposed to cycle at power up every time. What are your thoughts about the fuel pump not running at power up?
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PostPosted: Thu May 24, 2018 8:44 pm
If you wired up the fuel pump using the kit's connector, check it out. I had intermittent issues with mine to the point I took it out of the wiring and directly wired the fuel pump. I had a feeling it would fail when it was the least convenient.
The pump should run for a lot longer when you first hit the ignition switch than you mentioned....let us know what you find.
Mark Fick
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PostPosted: Fri May 25, 2018 10:45 am
Some of these were covered, but just to confirm a few things. I'm assuming you have access to a computer and are using the latest PE3 software during this process to check what's happening (e.g. check that fuel pressure is actually 45 psi and battery voltage is over 12.5 before starting. Make sure you download the sofware from the link on this page: https://www.scca-e.com/technical-information

Make sure that you can make a successful connection to the ECU using this software before you do anything else. Check that you're getting valid sensor readings (and steps below) before starting the car. You should get a warning if there's a difference between the ECU software version and the current PE3 software you're using. If so, you'll need to update the ECU through the PE3 software. I know we could do this before they password locked the ECU, so you may need a CSR to perform the update if this is process is password-protected.

1) Does the ECU light stay on after starting, or go out (it should go out?) You should not try to start the car until the ECU light goes out (I see guys having trouble starting when they get impatient and hit the starter button right after turning on the ignition switch). Wait a second after the fuel pump stops (if you can hear it) and try to start then. If the light blinks at any point check the manual for diagnostics.

2) Make sure you've calibrated the TPS before starting; on the PE3 it should read 0 when no throttle and 100 at full throttle (yes, I've tried to do it the other way around!) That can affect initial idle. This will show up in the PE3 software once you've powered on the ignition - check before starting. You can do this without the PE3 software (see manual), but recommend getting the PE3 sofware and ECU connections working first as that will help through the diagnostic cycle.

3) It's normal when first starting the car for the first time to go through an IAC calibration cycle. You need to let the car get up to full temperature (at least over 180, maybe more), without blipping or holding the throttle open, to allow the IAC calibrated properly. 2,500rpm and surging is normal part of the calibratoin process. Review the manual for the process if you're not sure. It should come down to a reasonable idle speed once this process is done.

As noted below, a bad IAC can be problematic. The usual symptom, though, it that the car won't idle at all. Guess it could also get stuck in the open position as well.

4) Charge your battery or connect another booster battery if you have starting issues. Some ECU's seem to be very voltage (or amperage) sensitive and if you've tried to start the car several times (especially with an older battery) it may contribute to a non-starting issue. I had fuel pump relay contribute to a starting issue since the draw from the starter was sufficient to cause the fuel pump relay to fail intermittently during the starting process. Diagnosed by swapping the two relays.
Bob Breton - SRF 51 - San Francisco Region

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PostPosted: Sun May 27, 2018 4:38 pm
I was going to comment with pretty much everything that Bob Breton wrote. When I first read the description of your problem, the idling part definitely sounded like an IAC issue to me. The part about the fuel pump not cycling is odd. It should cycle every time you hit the ignition switch. If the pump was installed using the SCCA Enterprises supplied Molex connector, you might want to check that to ensure you still have a good connection. If so, check all the other connections: master switch, ground wire to frame, ignition switch, relays, etc. As Bob said, maybe all of that is related to an old version of the ECU software.

One thing I would add from Bob's comments is that Mike Davies told me that the IAC has to calibrate itself. To do this, you need to start the car WITHOUT blipping the throttle at all during this process, letting the car get up to full temperature (Mike recommended 204 degrees, if your car will get that high). In the PE software, there's a diagnostic panel for the IAC. You can see it set to a calibration figure at some point after it reaches whatever temperature it takes to set it. I can't remember the figure range that Mike told me was normal. For my car, it seems to normally set somewhere around 195 degrees. But just make sure you let the car idle until it the IAC adjust figure changes. Mine normally 'idles' around 1400rpm until the IAC sets and it surges anywhere from 100 to 400 rpm until it sets. But then it settles down to a smooth idle around 1050rpm. If you need help with the diagnostic page in PE, let me know and I'll look it up. It's been so long since I've done it I can't remember how to get to the page or what it's called from memory. Better yet, reach out to Mike Davies and he can walk you through the procedure.

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PostPosted: Tue May 29, 2018 9:55 am
Update on my issue:

First off, a HUGE thank you to Mike Davies and Nikki (last name?) at Enterprises. The fuel pump issues was due to a corrupt ECU. We checked power on the middle pin of the ignition coil to verify the main relay was working. Then Mike had me check power on pin 34 of the large ECU connector to chassis ground - that was OK. As a last check we checked pin 34 to pin 18 on the ECU connector (ground) and that checked OK. Mike says the ECU was effed and had Nikki overnight me a new one.

Scheduled to leave for Brainerd Friday noon. Got everything loaded a prepped before Friday 10:30 am delivery of new ECU. Plugged it in and it fired right up! Finished P2 in the second race this weekend - and had an absolute ball. High idle was due to too tight throttle cable at the throttle body. once the car was running that was an easy fix.

ALSO - thanks to everyone on this forum, David Schaal and Brad at SRG Autosport, and Jim Nash and Steve Thomson who helped flog on the car with me this weekend. Looking forward to my next race!

Ron

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