I started my car up tonight and it had a rough idle right after startup, the car was shaking pretty bad and then it got progressively better as I let it sit for a moment. The shaking was most pronounced as the car immediately started up and went back to idle from ~2000 RPM. I heard no unusual noises from anywhere in the engine, but I did notice some black crap (looked like oil, but kind of powdery) that had literally been blown out of the tailpipes, it was sprayed in a fan shape on the garage floor and driveway. It initially starts up just fine and there's no CEL. Any ideas? This is just plain weird....
Idle problem again...?
- Thread starter pottsy
- Start date
Sounds like the IAC or could be the TPS
You say "again". What was the problem before? It's not so weird. My garage door has black circles out it from carbon ejected straight back to it from the exhaust pipes. The black powdery stuff is carbon, literally incompletely burned gas. A cold engine is run rich at startup. For some reason yours started richer than usual. I've had a couple of those kind of starts from time to time. They did not persist. I wrote it off as a glitch. Had it problem(?) continued I'd have probably cleaned the IAC.pottsy said:
Mhissticobra said:
Just because its the idle doesn't mean it has to be one of those two. It actually sounds like a bad O2 sensor.
SNAKEYE said:
It has done it once before, but it didn't do it again so I brushed it off. That seems to desrcribe what I thought it was, so if it doesn't do it again I won't worry about it. The IAC was replaced a few months ago, so I really doubt that is it. The 02 sensors were also replaced not even a month ago because I had a lean code (the 02 sensors fixed that).
My car did that once about a month or two ago. I started it and the car ran so rough it sounded like a cammed dragster and then it would die if I didn't keep feeding it fuel. It died three times and when I started the car the fourth time it ran as smooth as a baby's ass.
I kinda just wrote it off because it had never happened before and hasn't happened since... :shrug:
I kinda just wrote it off because it had never happened before and hasn't happened since... :shrug:
ProChargedSnake
Banned
Actually...it's in the computer. Mod Engine Cobra's are notorious for this. Can fix it with a computer tune(SCT,Diablo......)
ProChargedSnake said:
LOL, DAMN TUNES.
Mine has done this too, and it's "tuned"...maybe wrong...
I don't think it's a big deal, it doesn't happen often and goes away quickly. It's like a headache, you don't think about it till you get one and before you know it, it's gone!
ProChargedSnake
Banned
Seems like the more mods you do to these cars, the worse it gets. So far SCT has been the best to fix it, also depends on who tunes your ride!!
ProChargedSnake said:
Did you get the SCT Pro Kit (burner/chip/data logger/etc) and do it yourself? I REALLY want to do this but I imagine it takes some time to get setup and I have waaaayyy to much time already wrapped up in this Predator tune...
BUT, it would be really nice to lean out my idle!!! :nonono:
Mhissticobra said:
What is IAC and TPS, my car still has a rough idle after changing the plugs,wires,oil, and cleaning the imcr's and running sea foam through it. Could the IAC or TPS still cause my car to have a rough idlle.
96laserRedcobra said:
Change your fuel filter...
IAC = Idle Air Control (the culprit of MANY problems with our engine's idle)
TPS = Throttle Position Sensor (Last year my car was stalling out at idle and this was my problem - an easy $5 fix, hence why I mentioned it as a POSSIBLE problem to pottsy.
TPS = Throttle Position Sensor (Last year my car was stalling out at idle and this was my problem - an easy $5 fix, hence why I mentioned it as a POSSIBLE problem to pottsy.
96laserRedcobra said:
ProChargedSnake
Banned
TPS & IAC would be good to check. TPS needs to be as close as to.98 as possible. May have to drill out the screw holes a little. If you have a tune done....do it on the Dyno!!!! Much better driveability than a mail order tune.
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