fly89gta

iTrader: (1)

OK guys, I'm going to give as much info as possible here.

Mods are in the sig, recently pulled off the intake to block off the EGR valve. While in there the TB was all cleaned out and the IAC was replaced with a new piece.

Now the idle is high and at times the car will drive itself. Also, if going anything over 60mph and you put it in neutral the rpm's won't drop, they stay at around 2K unless you blip the throttle a bit and it sometimes drops.

Now, I don't know all of the settings in the chip(previous owner burned it). My question is this. If he tuned the car with a gunked up TB and an IAC that "may" not have been 100% could the tune be off? One other theory that someone I trust says the regular ATI bypass valve sucks and that the boost is pushing through the throttle blade. Now in theory that makes sense but why would that happen now? Is it because everything at the TB And EGR are all tight and sealed?

No vacuum leaks, nothing out of the ordinary is visible.

I'm leaning towards the chip needing to be tweaked but I really don't know enough to argue. I don't want to drop $400 on a racegate if that's not the problem.

Any ideas or suggestions? The problems are intermittent but it's getting a bit worse, it seems like hitting the throttle for a second will bring the rpm's down...however it doesn't help it all the time. It also seems to do it more frequently after getting on the throttle/driving hard. Sometimes I really have to fight with the brakes to get the car to stop.

This is also posted in the power adder section. I figured I'd ask here as well in case anyone has experience with blown cars. I have access to a GM Tech1/Tech 2 here at work in case you guys need specific sensor readings.

****I AM NOT ASKING FOR SOMEONE TO BURN ME A CHIP, MERELY POINTERS ON WHAT TO LOOK FOR******

Thanks guys!

Big Dog Chevy

Check and recheck the throttle linkage to make sure it is not binding up and not returning to the closed position after it is opened. Add a small return spring to the thottle linkage first and see if that solves your problems. Remember check the little things first. When you say you blip the gas and it comes down that let's me to think something was stuck open.

fly89gta

iTrader: (1)

Well it figures that when I hooked up the Tech1 up at work the car was fine lol.

I really wanted to see what the TPS and IAC counts were at so I could see if it looked like it was either of them causing the problem

For anyone else, is there a chance the blower is now, all of a sudden, blowing the throttle blades open?

Big Dog Chevy

Add second return spring to see if that's it. Cheap and quick fix if it is.

fly89gta

iTrader: (1)

Thanks.

Also, if it helps....sometimes when the idle is high at idle(at a light) it'll suddenly drop back to normal like someone flipped a switch. Is it possible the new IAC is just getting hung up?

Orr89RocZ

iTrader: (20)

Could be IAC. Could be a sticking throttle at somepoint in the linkage to the pedal. Possibly a tune problem since you could tune car with a clogged up TB/IAC and then clean it and have things way off. Hasnt happened to me but i can see how that may happen.

The blower shouldnt be blowing the TB open at idle...not enough air flow there. To rule it all out, try disconnecting the blower output to the TB and let the car idle and see what happens now.

Let the IAC close and disconnect the sensor and see what happens. May show that the IAC is the culprit.