2017 Camaro baby cam/headers 20% diff in fuel trims?

eb02z06 · 01-03-2022, 09:53 PM

Note-I've posted this is in the tuning section-but this doesn't seem to be a tuning a issue. And for the life of me and many others that have looked at the logs and tune-don't understand what is going on.

Here is what is going on:

I've been struggling with a 2017 Camaro I modded about a year ago. It's a 17 that came in for oil consumption, had around 187 000 miles on it. We took it apart and refreshed the motor. Customer wanted a mild Cam while it was a apart so we installed the smallest GPI cam since it still has a stock stall and TCM tune. So the mod list is a refreshed motor, GPI SS1 cam, Rotofab intake and Kooks headers. Dyno's 467 rwhp and went on its way. Fast forward 40 thousand miles later and it's back. Mild tick and running rough. Originally customer took it to the dealer and they swapped injectors. Still ticked and was running rough so he brought it to us. We found 1 rocker where the trunnion let go. Replaced it with a new rocker and no more tick. But it was still running rough. logging it Bank 2 is pulling around 18-20% more fuel than bank 1. So we installed new 02's-no difference-installed 02's from a good working car-no difference. Now the car wont even run longer than a few minutes after the Bank 2 starts pulling fuel. Low side is giving what the ecm is commanding as well as the hi side. Did a leak down test-all good, compression test all good. Swapped hi side pump, no diff, did a smoke test-nothing. Swapped injectors-nothing. At this point were completely lost. One thing that is weird is if you unplug the fuel pressure sensor at the rail the car will idle at 1500 rpm and then the fuel trims now be 30% lean on bank 1 and about 8% lean on bank 2 but it won't shut off now. Absolutely totally lost here. If anyone can help me solve this-I will pay you! Any input would be greatly appreciated. I am totally lost here. TIA!

Kerry · 01-03-2022, 10:08 PM

blocked cat

cmitchell17 · 01-05-2022, 07:44 PM

Whats the misfire counters showing? I know I have messed around before only to find out I did have a bad spark plug, these new irridium plug electrode tips are extremely sensitive to damage even if you just touch them with some metal, that's why I think they say not to adjust the gap yourself.

Also I thought I had the highest milage at 100k haha. Someone had to been straight up driving non-stop or either running drugs or something.

01-03-2022, 09:53 PM	#1
eb02z06 Drives: 19 Z06 Join Date: Dec 2018 Location: Elmira Posts: 13	2017 Camaro baby cam/headers 20% diff in fuel trims? Note-I've posted this is in the tuning section-but this doesn't seem to be a tuning a issue. And for the life of me and many others that have looked at the logs and tune-don't understand what is going on. Here is what is going on: I've been struggling with a 2017 Camaro I modded about a year ago. It's a 17 that came in for oil consumption, had around 187 000 miles on it. We took it apart and refreshed the motor. Customer wanted a mild Cam while it was a apart so we installed the smallest GPI cam since it still has a stock stall and TCM tune. So the mod list is a refreshed motor, GPI SS1 cam, Rotofab intake and Kooks headers. Dyno's 467 rwhp and went on its way. Fast forward 40 thousand miles later and it's back. Mild tick and running rough. Originally customer took it to the dealer and they swapped injectors. Still ticked and was running rough so he brought it to us. We found 1 rocker where the trunnion let go. Replaced it with a new rocker and no more tick. But it was still running rough. logging it Bank 2 is pulling around 18-20% more fuel than bank 1. So we installed new 02's-no difference-installed 02's from a good working car-no difference. Now the car wont even run longer than a few minutes after the Bank 2 starts pulling fuel. Low side is giving what the ecm is commanding as well as the hi side. Did a leak down test-all good, compression test all good. Swapped hi side pump, no diff, did a smoke test-nothing. Swapped injectors-nothing. At this point were completely lost. One thing that is weird is if you unplug the fuel pressure sensor at the rail the car will idle at 1500 rpm and then the fuel trims now be 30% lean on bank 1 and about 8% lean on bank 2 but it won't shut off now. Absolutely totally lost here. If anyone can help me solve this-I will pay you! Any input would be greatly appreciated. I am totally lost here. TIA!

01-03-2022, 10:08 PM	#2
Kerry Drives: 2019 2SS Camaro Join Date: Apr 2012 Location: Al Posts: 828	blocked cat

01-05-2022, 07:44 PM	#3
cmitchell17 Drives: 17 2SS, 8L90, Cam, Heads, E85 Join Date: Dec 2016 Location: US Posts: 1,204	Whats the misfire counters showing? I know I have messed around before only to find out I did have a bad spark plug, these new irridium plug electrode tips are extremely sensitive to damage even if you just touch them with some metal, that's why I think they say not to adjust the gap yourself. Also I thought I had the highest milage at 100k haha. Someone had to been straight up driving non-stop or either running drugs or something.

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