I have recently swapped an L36 into a Fiero and I think I am having some issue with the idle. It seems to fluctuate more than I expect it to. Is this normal for the 3800? It's my first one.
It's a 100% stock tune (99 Grand Prix). The car still has it's pre-cat O2 sensor, the EGR has been removed (not disabled via HPT yet).
Other than that, the motor is stock. Attached is a log of it idling as well as the tune. Any help is appreciated.
Is the EGR simply removed or replaced with a blocking plate?
Check before you consider tuning;
Is the MIL on? ANY leaks-vacuum, fluid or exhaust? Clogged filters? Old O2 or dirty MAF sensors? Dirty injectors, PCV or IAC passage? Correct the condition. Change the plugs & oil while you're at it. They need it anyway. Particular system giving you fits? Visually examine the related wiring first.
ZZP Block off plate.
Start with the easy and cheap stuff. Clean the MAF and IAC, then spray that cleaner around gaskets on the induction side during idle. If doing that produces a surge or stumble, you've found a leak. Don't forget the seal under that ZZP plate too.
If all that get's you nowhere, start looking closely at the wiring that goes to the TB.
Still nothing? Focus on the exhaust and the O2 fitting. Bad leaks there can cause surging too.
Check before you consider tuning;
Is the MIL on? ANY leaks-vacuum, fluid or exhaust? Clogged filters? Old O2 or dirty MAF sensors? Dirty injectors, PCV or IAC passage? Correct the condition. Change the plugs & oil while you're at it. They need it anyway. Particular system giving you fits? Visually examine the related wiring first.
Now that you mention it, it does leak at the beginning of the downpipe. The exhaust is temporarily poorly put together. I'll do some cleaning with the MAF and IAC. Starter fluid hasn't revealed any vacuum leaks, but I'll keep checking.
Thanks for the tips!
Use the scanner as well to check the tps on it to make sure its working properly. Seems if any moisture hits those at all they are at a high risk of crapping out, and it really goes haywire at idle
2000 Trans Am WS6
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