rtagg

iTrader: (2)

I have an LS2 from an '07 Corvette with the original E38 ECU swapped into a Fox Mustang with a Current Performance wiring harness. Using HP Tuners, I've removed the two VATS patches, and the Starter Fault checks, done a Write All on the OS, and the motor fires right up and dies within a second. I have 60 PSI fuel pressure at the rail, I can hear the pump running right after the motor dies, and there is oil pressure when it's running. When the motor is running, it's at around 1500 RPM, and sound like its on all 8. I thought that maybe the voltage was dropping while cranking (old battery) and the ECU wasn't initializing but I just put in a new Johnson Controls 690CCA battery and it cranks faster but didn't fix the problem.

Have I missed something? I've attached a copy of the ECU read after I removed the VATS. I'd appreciate any help, this one has me stumped.

Thanks

SwapStang

I remember reading a while ago someone having a similar problem. It turned out while he had good oil pressure running (read with a mechanical gauge) his PCM needed to see the oil pressure sensor. They're pinned into the PCM unlike the gen3 that I have, those feed a gauge directly. I'd start there. Let us know.

cam

iTrader: (9)

Disable starter interlock

rtagg

iTrader: (2)

Swap,
I remember seeing that too, because at the time I had removed the factory electronic sensor in favor of a mechanical gauge. I replaced the factory sensor and ran my mechanical gauge to the oil cooler block off plate, so unless the factory sensor took a dump, that can't be the problem.
Just to be sure, I plan to remove the factory sensor this weekend and bench test it.

Cam,
Are you referring to the Starter Fault Checks option that is located in the OS section next to the VATS? If you are, I've done that, but if there is something located in another area please let me know, because I've missed it.

Thanks for your input.

cam

iTrader: (9)

I dont have my HP handy so I cant check your tune. I re-read your first post and see you commented on the interlock which I had missed. I believe there are two sections for Vats that both need to be disabled. Its also critical on the e38 that the ECM bat and ign feeds are correctly pinned

rtagg

iTrader: (2)

Cam,
If you can at some point take a look at my file I'd really appreciate it. The only VATS options I could find were VATS Patch1 and VATS Patch 2 which were located in the OS tab in HP. The first time around I disabled both along with Starter Fault Checks but only did a Write Tune Instead of Write All. After finding that mistake and doing a Write All, I read the ECU and it's showing both VATS patches and Starter Faults disabled. That ECU read is the file I've posted.

The wiring harness is a brand new one from Current Performance, but if the test on the oil pressure switch doesn't show anything wrong, I guess the next logical step will be to start checking wiring pin locations.

cam

iTrader: (9)

You should be able to set up a pid and log the oil pressure switch with the scan tool but I will see if I can dig out my gear and check that later

rtagg

iTrader: (2)

I'm fairly new to HP and haven't done any logging yet, but I'll check it out, thanks.

SwapStang

^^This^^
I was going to say just log it and see if it's actually seeing any oil pressure. I've done nothing with newer pcm so I don't know much about them. These starter fault checks you guys are talking about do what exactly? Is it more to check safeties to engage the starter or is it more for once the car is running?

rtagg

iTrader: (2)

Well I think I've found the problem. Today I stopped by a local tuner shop recommended by a friend, and the LS expert there took a look at my tune file and said that someone had started to set up the ECU for a boosted application and didn't finish it. In his words, "There is no way this motor would ever run with this tune." I have no idea how that happened, but I bought the motor and ECU from a Corvette recycler out of state, so I assume the original ECU was damaged and they just grabbed another Corvette E38 off the shelf to complete the package.Anyway, the tuner was nice enough to provide me with a stock tune for my E38 ECU to see if I can get it up and running, so my plan is to write the stock OS and tune into my ECU tonight and see what happens. I'll report back once I try it out.

Swap,
I have no idea what the starter fault checks are about, only that you need to disable them along with VATS to get a stand alone motor to run.

SwapStang

That's quite a strange situation but as long as the new file will clear it up I guess that's all that matters. BTW I know you said you were new to HPT but if you set up an account on their website and register your device you will have access to their tune repository. Can be helpful especially in this situation when all you needed was a stock tune. Can't wait to hear how it works out.

rtagg

iTrader: (2)

Well, a clean copy of a stock Corvette LS2 tune and OS fixed the problem. What I found was that even in the stock tune, if I opened the OS tab, there was a button in the "Code Modifications" area that said "Apply Code Modifications". As an experiment, I took a copy of the file and clicked on it and sure enough, the tables that were zeroed out in my tune, zeroed out in the new tune. So now I know what happened, just not when. I loaded a clean copy of the stock tune (had to do a "Write Entire") and it worked. The motor now fires right up and idles smooth. Now I just have to build the rest of the exhaust and the car will be ready for shake down.

Thanks to Cam and Swapstang for your input, I appreciate it.

SwapStang

That's awesome I'm glad that worked for you. Nice when you aren't chasing a gremlin for too long haha. I'd buy that tuner a case of beer for the help too!