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On from one issue to the next, now if I let the car idle for a little while I will get a series of idle surges where it goes up and down in rpm...I had my scan tool on it while it did this and the IAC counts went up and down as well... I also threw a vacuum gauge on and when it does this vacuum goes from 20 to 15 and back and forth but then the idle corrects itself and idles fine. Car runs and drives pretty good it’s just once you let it idle for a little while it acts up.
Here are some scans from of what I have when it’s idling:
Block learn fuel trim at 108 is signaling a problem.
Integrator at 80 indicates ECM is completely out of ajustment range. Something is causing the engine (at least the driver side where the O2 is) to run very rich and the ECM is trying to pull fuel out.
Leaking injector? Too much fuel pressure? Bad ignition component? Faulty o2 or other sensor?
Fuel pressure is at stock spec of 43-44 with vac line unplugged. I’m not getting the nasty/smoky start ups of leaky injectors like I had before they were replaced. The entire ignition system was replaced over the last few years along with many sensors including O2. No check engine lights either.
Well I think I may have figured this out, on a hunch I swapped out the Delphi MAF for my OEM Bosch that I kept around. My data scan now reads much different than before and no idle issues.
Here is the new scan:
Notice the MAF readings are now back to spec and BLM and INT are also much improved I believe.
Good work. I looked at your original post and completely looked past the 9.94 on the maf so I didn't have any good input. That should have been a red flag for me. Glad you got it.
04-23-2021, 09:48 AM
