Excelerate

iTrader: (1)

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.

Excelerate

iTrader: (1)

No ideas or similar experiences?

rbf351

my car does the same thing, but only when i have the AC on

N.O.6speed

^werd, same here also!

davo-cls

Idle control valve going R.I.P.

I'd have that checked out first.

Excelerate

iTrader: (1)

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.

Pure Adrenaline

iTrader: (2)

What was the weather like today? Hot and humid, maybe?

My car has a tendency to do that sometimes when it's hot and humid out. Just slight bogging is what that is.

blader

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.

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.

blader

You should really get that checked out. There is NO reason you should have to change the plugs 3 times in 85K miles on a naturally aspirated car. Infact I think the first scheduled change is 105K.

bigguyonbike

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.

scalbert

Not nessesarily. It may not throw a code at all for a sticking IAC. The signals are comeing back alright but the valve may not be reacting as it should.

I suspect it to be the IAC, just keep an eye on it.

Excelerate

iTrader: (1)

I tried duplicating this again and I found out it only happens when the A/C is on. I haven't changed my A/C filters at all but I do not think this is the problem. Is the A/C drawing too much current from the alternator and affecting the idle?

Ogolden1

Yeah, I recently noticed that mine is not increasing the RPM when you turn on the A/C like it used to! ...Would that be the Idle Sensor???

MethodRN

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

CLpower

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.

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??

BigLizard

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.

BigLizard

It's not always the plug or the wires when an engine misfires...remember to look outside the box.

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.

ghost_masterCL

not necesarrily. just because it doens't work right doens't mean you'll get a CEL.