Idle Dropping?
#1
Idle Dropping?
I've noticed lately something funny with my 01 CL Type S. Just FYI engine mods are CT headers and intake. I was watching my RPM's at idle yesterday and I noticed when I come to a stop the idle dropped slightly below 500 and then rose up quick to 750-800, which I believe is normal idle range. It did this a few times and I know generally this occurs if there is a problem with the IACV or there is a vacuum leak or possibly if you're in limp mode. But I'm getting no CEL's. I still need to check the vacuum lines. Any other ideas? Oh yea, I was in 2nd gear and I had revved the car to about 6k and then I let the car rev down quick b/c I had to turn into a road and as I turned onto the road my car died - not good b/c if someone pulled in I was getting rear-ended and it would have been my fault.
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#8
Audi S4 driver
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Weird, mine did it alot in the winter. Infact there were ALOT of threads during winter and alot of people reported that happening.
It was happening to me a few weeks ago after I put in the unichip. Little did I know, I had the switch on the unichip for the ECU turned to the OFF position. So everytime I shut the car off, the ECU dumped everything it learned on that drive.
Flipped the switch on, let it run through the idle learn procedure and havent had the problem since.
Hey have you disconnected your battery anytime lately? If you did and didnt let it run the idle learn procedure it could probably cause that. If not, just unplug the negative terminal for like 20 minutes then put it back on, start the car, and let the car idle for like 15 minutes. then drive. it might fix it.
It was happening to me a few weeks ago after I put in the unichip. Little did I know, I had the switch on the unichip for the ECU turned to the OFF position. So everytime I shut the car off, the ECU dumped everything it learned on that drive.
Flipped the switch on, let it run through the idle learn procedure and havent had the problem since.
Hey have you disconnected your battery anytime lately? If you did and didnt let it run the idle learn procedure it could probably cause that. If not, just unplug the negative terminal for like 20 minutes then put it back on, start the car, and let the car idle for like 15 minutes. then drive. it might fix it.
#9
Instructor
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I have the same problem and the car died on me a few times, but lately it has been fine, dont know the problem but I think it might be the spark plugs because I have only 85k miles and I have change the plugs 3 times already.
#10
Audi S4 driver
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Originally Posted by 916CL
I have the same problem and the car died on me a few times, but lately it has been fine, dont know the problem but I think it might be the spark plugs because I have only 85k miles and I have change the plugs 3 times already.
#11
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it happen to me acouple times before i got new plugs. the car would idle to around 500rpm for a second or two then back up to 750rpm when i'm at a red light. my advice would be to get new plugs.
#12
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Originally Posted by Excelerate
The problem though has not duplicated itself. And if it were the IAC Valve then I would have thrown a CEL so I can't see why it would be that.
I suspect it to be the IAC, just keep an eye on it.
#14
Oh...Behave!
Originally Posted by Excelerate
I tried duplicating this again and I found out it only happens when the A/C is on. ?
#15
HELLLLLLOOOOOO NURSE!!!!!
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I experienced the same problem about a week ago. Funny that I came across this thread. The thing w/ mine was my battery died on me and I only started noticing it after that. After I changed out my battery I haven't really noticed it doing it. I attributed the problem to the ECU just relearning. After about 100miles I haven't had the problem
#16
teh Senior Instigator
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Originally Posted by Excelerate
The problem though has not duplicated itself. And if it were the IAC Valve then I would have thrown a CEL so I can't see why it would be that.
not necessarily, my car did the same thing and it took about 3 months to finally throw a CEL. I just resetted it and it never came back but eventually replaced it.
#17
Problem with idle with intake
wassup guys i got an 01 clp and its been running pretty good till recently i got an intake and as soon as i drove it hard and to have fun with the intake the check engine blew up then the tcs light ???? then i tookit back to my mechanic and showed up misfire on 3 cylinders so he cleared it and changed the plugs and it was good for 2 days then it started again my friend said it might be going in limp mode now my check engine is on and the idle is rough what can i do to fix all this and keep my intake??
#18
Moderator Alumnus
This has happened to me before the knock sensor went out. The car was in limp mode forever until I got the sensor switched.
More than likely your car is in limp mode and CEL hasn't been thrown yet because the engine's problem isn't horrible right now.
More than likely your car is in limp mode and CEL hasn't been thrown yet because the engine's problem isn't horrible right now.
#19
Moderator Alumnus
Originally Posted by cubaknow
wassup guys i got an 01 clp and its been running pretty good till recently i got an intake and as soon as i drove it hard and to have fun with the intake the check engine blew up then the tcs light ???? then i tookit back to my mechanic and showed up misfire on 3 cylinders so he cleared it and changed the plugs and it was good for 2 days then it started again my friend said it might be going in limp mode now my check engine is on and the idle is rough what can i do to fix all this and keep my intake??
Check all of your sensors to see if any are broken and need to be replaced. Sometimes the coils will make the engine misfire too.
EDIT: Holy cow this thread is old.
#20
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Originally Posted by Excelerate
The problem though has not duplicated itself. And if it were the IAC Valve then I would have thrown a CEL so I can't see why it would be that.
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