The issue is when I disengage the clutch to come to a stop, the RPM's begin to decrease but don't stop at the normal idle, they drop below and the car almost stalls. I want to say the car idles right around 500 RPM normally (Cobb AP Stage 2 93 Octane map). Mind you this is only at the begining of each session I drive. After minutes of driving it goes away. I thought it may be because the engine was cold, but it's happened after I've allowed the engine to reach normal operating temperature. It seems like the RPM's drop when a component starts up, I'm not sure what component that may be I'm not a mechanic. Any help would be great, it's starting to get sketchy, thanks.
What blow off valve do you have? This is common with cars having a blow to atmosphere blow off valve instead of recirculated.
I'm running the stock bov. Maybe there is a leak in the vacuum line? I installed an aftermarket boost gauge but my readings are still consistent with what they've been in the past.
Also do you have your vent dial set to defrost? I've noticed with mine set that way when rolling to a stop my rpms drop down more then normal but always come back up fine.
When the defroster or AC is on and the fans kick on, it WILL make the RPM's fluctuate/drop. But it shouldn't actually stall on you tho.
I figured that but it's annoying that its happening. It didn't do this last year while blasting AC or defrost in the winter. It literally feels like its going to stall and at the last minute it jumps back up to idle. I feel like it can run more smooth. I think it may have something to do with the map I'm running. Ill have to log it like Ronnie suggested and go from there.
I notice this at times, I thought it might a little bad gas or the defrosters kicking in. It goes away after it warms up tho.
I haven't dug into it any further. All I know for a fact is that it only happens when the defrost is on and it goes away after the engine gets to temp...
On my 05 STI when I turn it to defrost the A/C comes on and I then have to shut off the A/C. I have always wondered why the hell this happens.
Guys I work with ask me this all the time. "Hey Dave, what's wrong with my car? Every time I turn the defrost on, the light for my A/C comes on." It is something every car does. And its normal.
I'm laughing because the op felt he needed to let us know more info after he has been told the problem.
