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Idling extremely rich, rough.

Old 11-26-2008, 01:56 PM
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Default Idling extremely rich, rough.

Posted this in the Emanage section but I thought i would try here.

My car had a recent engine rebuild. I replaced the rods and pistons with Belfabs. 78mm overbore on the pistons.

It was running fine, but stalling when coming to a stop when warm. That was a problem before the rebuild though. I was driving on surface streets and the car bucked and stalled, wouldn't start immediatly, then idled really rough once it did start. A mechanic did manage to get it running again temproarily. Same thing happend on the freeway. Aftermarket stuff I've checked were BEGi FPR, and reconnected my stock EMB cutters. I took it to my mechanic and he's replaced practically everything stock involved in fueling. Checked the AFM, fuel pump, coils, spark plug wires, and spark plugs. It ran again, temporarily, now it's back to doing the same thing, idling rough and rich, and stalling.

The only thing i can really think of to check next would be the O2 sensor/wiring (Bosch 4-wire), or maybe the Autotune/wiring and EMB/wiring, maybe even my Piersburg.

I just sent the wiring instructions for the Autotune to my mechanic.

Other than that, anything i could have missed?
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Old 11-26-2008, 02:04 PM
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Wish I could help. My only suggestion is to isolate the problem. IE-if it's a fuel pressure problem, a loss of spark problem, or a Emanage problem.

I'd put a fuel pressure gauge on it so you can monitor it at all times and see if there's a correlation between fuel pressure and running like ****.
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Old 11-27-2008, 01:00 AM
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have you reset your base idle?
Are you certain there is not a vac leak?
I second getting a fuel pressure gauge.
You've got an emanage, how about logging for awhile to see what might show itself?
Were your injectors cleaned?
Does it kick any CEL, and have you checked for codes even if it doesn't?
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Old 11-27-2008, 01:26 AM
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How is your master fuel and injector offset looking?
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Old 11-27-2008, 01:35 PM
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Thanks guys,

Turned out to be a whole bunch of things going wrong all at once. The 12v source for my 4-wire O2 sensor loose and shorted. Some of the cutters from my EMB harness were a bit loose as well. Apparently, the coils were also weak.

My injectors had recently been seviced an cleaned.

How is your master fuel and injector offset looking?
This, however, might need to be looked at. I've been having stalling problems going back at least 6 months that I have not been able to fix.

How do I check the master fuel and injector offset?
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