SixSpeed

I need the some help from you guys...When I'm driving - every once in awhile when I push in the clutch I notice that my rpm's are only going down to 1,200-2,000. When I am sitting still with the clutch in it's the same thing, but since I'm stationary I can feel the car idling ruff as well. I reset the computer and 30 or 40 miles later it's starts doing it again.

Also when the AC is on is when I first started having this problem. Turn on AC and the car immediately drives like I'm only using 4 cylinders and runs really ruff and the idle problem above happens. Now the idle problem is happening without the AC on. It's not like anything is sticking because it's different rpm's every time.

This morning when I started her up the rpm's jumped to 2,500 !!! Then after about 30 seconds went to about 1,200 with ruff idle. After about a minute the rpm's returned to normal. So, I put it in gear and left. Took it out of reverse to put it in 1st and the idle problem was already back!!! WTF!!!

Can someone please help. I feel bad for my baby! Sorry this was so long!

Dave Carney

Check your EGR o-ring in the top of the intake. It sounds like a vacuum leak.

LightweightZ28

iTrader: (2)

Also could be the idle/air control sensor on the throttle body. I had that go out on my 98 Camaro and the idle acted just like yours is doing. Took 3 trips to the dealer for them to figure it out, but the last time I brought it in it was idling at 3700rpms so it was easy for them that time, lol. Good luck.

SixSpeed

Thanks guys, so could those be related to the AC problem as well! Sounds like it could!

highgear

Check for a stuck PCV or EGR. Mine went wacky yesterday after running just fine. Started it up after sitting for 2 hrs and it would not idle at all. After 2-3 restarts, it returned to normal. Maybe the computer went crazy for awhile. I dunno but it seems back to normal for now. Damn computer cars!

SixSpeed

Ok guys, I replaced the EGR O-ring. That didn't help a thing and the old one looked fine. So I went and bought an idle/air control sensor for 70 bucks and that didn't help anything either.

I found a cool guy in service at a local dealer but he can't figure anything out either. The problem with that is it NEVER acts up at the dealer. I've even driven it around for 45 minutes just to make it **** up so I can take it in. As soon as it starts going crazy I try to get back to the dealer, but by the time I get there it's only idleing at like 1900 so I don't take it in.

More symptoms: Ok, I though this was really odd. Like 6,000 miles ago I had the top end and injectors cleaned (I still had this problem before this but not as frequent). So last week we took the lid off and the throttle body was SOLID BLACK. WTF!!! And I mean Solid Black!!! The dealer sprayed it down and it drove like a new car for about 10 miles and now the problem is back. The only thing the dealer can think of is that I've got an injector going bad. What are your thoughts on this? This is driving me crazy!!!!

SixSpeed

Oh yeah, the car has never thrown any codes and the history was clear as well...WTF!!!

Vents

iTrader: (9)

does the car eat oil? might chevk the pcv setup. mine does this as well, but i've got a little more than a stock motor..

SixSpeed

Yeah you do, you lucky bastard!

Nope, Oil is fine. I also changed the fuel filter and PCV valve recently so that narrows down whats probably not a problem. What else is there to check on the PCV system?

Can an injector be "going bad" without throwing a code?

SixSpeed

Any thoughts?

I need to do a clutch swap and would like to get this problem taken care of first...Thanks!

SixSpeed

Anyone!!!?

LS1MONSTER

iTrader: (1)

hmmm...new pcv, egr is fine and a new IAC. And the dealer doesn't know whats wrong?? You need to visit another dealer. They need to take a scanner to the car, run a movie on it. Something has to be causing this. Only thing that comes to mind is the IAC. But you said you replaced that. How did you know the IAC was defective? Are there any other mods that you don't have listed? Double check everything..plugs wires connections etc. Items like the egr and iac can be tested to see if they are working properly. Your dealer should have checked all that out. My advice seek another dealer.

SixSpeed

The dealer probably would have checked it out better but he was doing it for free. He through a scanner on it and nothing was wrong...

The problem seems to happen more frequent when I have only a 1/4 tank of gas or less.

I'm think'n that it has something to do with my throttle body turning black so quick. I don't have any extra mods that aren't in the sig and I have never sprayed it.

I didn't know the IAC was defective and turns out it wasn't. I got it to narrow down the search and because the advice from this thread. Not knocking the thread. I've always recieved great advise. I just apparently have a unique problem that never happens when I take it to get checked out...

Someone else suggested the throttle position sensor but when the idle is acting up I definitely have a loss of power so to me that rules that out.

Any thoughts would be appreciated!!!

Derek98z

iTrader: (55)

Is your TB recently ported? Over porting will cause this. Also the idle air controller spot on the TB may be gunked with build up. Buy the specific TB cleaner. It worked on my car.

Derek98z

iTrader: (55)

Also, have you changed your fuel filter lately? Could get speratic line pressure.

SixSpeed

It's not ported but I have been thinking of doing so. The IAC really wasn't clogged or anything and I have change the fuel filter within the last 6,000 miles. I had the problem before that swap and still do.

It's almost like the EGR is throwing to much crap back and it can't burn it off or I've been told an injector can throw crap back up in there too.

I'm leaning towards injector because of the power loss...

There seems to not be very many things that can cause this so I guess I'll keep trying to take it to the dealer when it's acting up. Thanks though!