Hi
i have a camaro V6 2.8 it's hard to start when cold but that's not what i am worried about at the mow
when it does start it warms up ok and settles at 750 rpm but when it has been ran for 10 mins or so going to work it starts sticking at about 2000 rpm if i jab on my Throttle the rev's go up and then slowly down to 1000 rpm and then to 750 rpm but this does not always work
i have replaced the IAC but not change
any help please

Alex

 

Mine does this every so often. I haven't been able to track down what causes ir ro happen. There realy shouldn't a need to jab the gas. Just tap it and will go down. One day I was a stop light next to a cop. With out think I jabed the gas. Imagine look on my face when I looked to right see why there were red and blue lights flashing. Fortunetly he bought my story.



So now istead of jabing the gas I just tap it. Much less atention getting

 

Alex, you might just need to clean the throttle body, AND the IAC passageway. The IAC is a stepper motor, with a pintle; you've seen that bit. What the pintle does is plug up a little hole. That hole runs to the front of the throttle body, to the passenger side of the butterfly plate. You can see this by taking off the rubber intake hose from the front of the TB.

When you take your foot off the gas, the IAC motor retracts the pintle. This lets a controlled amount of air bypass the closed throttle plate, and keeps the motor from stalling. This IAC passageway can build up carbon inside it, which restricts it. The whole TB and Plenum also build up with carbon.

So go to the local Pep Boys/Autozone/Strauss/etc and go to the spray can area. Near the Carb/Choke Cleaners, you'll see "Throttle Body and Air Intake Cleaner for fuel injected engines"... this is the stuff you want.

With the car off and keys out of the ignition, remove the IAC valve. Remove the air intake hose. Spray the cleaner into the IAC hole (might have to probe the IAC opening with the spray can extension tube to find the hole). You'll see carbon flow out of the passenger side front of the TB. Keep spraying until the stream is clear.

If your new IAC's pintle has carbon on it, you can spray it, too. Hold the IAC motor so the connector points "up" and the pintle points "down"!! This keeps the cleaner from dripping inside the IAC motor- which could damage the windings. Hold the IAC in that position until the cleaner evaporates.

Then reinstall the IAC.

After reinstalling the IAC, follow the directions on the back of the can to clean the throttle body and plenum. Remember to use a "spray for 5 seconds as you work the throttle linkage, wait for 10 seconds" pattern. This prevents the catalytic convertor from overheating and destroying itself, and helps keep the oxygen sensor carbon-free. (Oxygen sensor is self cleaning as long as it doesn't get a shtload of carbon dumped on it all at once!)

 

Hi
First thanks for the help
Any way took the TB apart and cleaned it you could eat your dinner off it, it’s so clean put it back in and it's still sticking if any thing it's worst now sticking some times at 3000 rpm
Could some one tell me what controls the revs when it's cold and where it is?
Could that be getting stuck even when it is warm or if I have an air leek where should I look
Or tell me any thing that would cores this to happen

Wooo yes I just remembered that I hear a noise like I pop or ping in the dash or behind it very low I have to listen hard to hear it but when it goes the revs go up or down what could that be ?

Alex

 

This is the same problem that I am having. Can't pass smog because of it(See my post about needing help, pretty recent.) I cant get it to idle below ~850. If i sit for a while(at a red light) after the engine has warmed up the SES light comes on, then goes back off after getting up to speed(about 40mph). I can't figure out thte problem . It is starting to bother me since I can't get it to pass smog with a high idle here in California. I cleaned the IAC port, throttle body/plate, and plennum, but to no avail. Any solutions would be awsome. Also, since i cleaned everything, the throttle sticks shut and it takes a little extra force to get it to open, and won't snap shut again unless it snap it. Hopefully we'll both get an answer for this(and a cheap one at that).

 

I think i may have solved the problem. Go down to the local auto parts store and get some White Lithium Grease in a spary can. it cost me like 3 bucks. Spray it on every point of friction you can find in the throttle body. Do this when it's cold though. You don't want to be spraying something flammible like this onto a hot engine. Work the throttle back and forth until until it's smooth and it should work again. It seems that as the engine warms up, the throttle plate and shaft warp and expand ever so slightly because of the heat and make it so it doesn't close all the way. Besides, the car is approching 15 years old, and when was the last time you lubed your throttle body. It has moving parts just like the engine internals and needs the lube. Good Luck. Now my problem is that i can't get it to idle below ~850, even with the idle screw all the way back. Dunno how I'm gonna fix this.

 

I had a similar issue on my '87 Camaro. As simple as it seems, I overlooked it. The gas pedal arm was just barely rubbing the bracket, and it was just enough tension to keep the throttle blades from fully closing.