Is it possible? I mean it is electrical, so anything electrical could go bad. I ask because i have been having trouble with my cobalt for awhile now. It doesnt run right and idle is all over the place and stalling on its own.

Ok story time

I asked my girlfriends father to just take a look at the car and see what he thinks it could be, and yes hes a mechanic for cars and motorcycles and all that neat stuff. Well i tried everything new O2 sensors, new vacuum lines, cleaned everything especially the TB. Well he checked it out today and he was searching for vacuum leaks first and looked at the motor up and down for somethig stupid that could cause it but nothing. He then ran a diagnostics on it and realized my gas pedal wasnt working correctly or may be. Now it gives him question as about the TB and gas pedal. Is 13 to 18% too high for idle? And he would put the gas pedal to the floor and only get 80 to 88% open on the TB. He doesnt think thats normal, car was running and he would notice the TB was opening up all over the place and when hitting the gas pedal slightly it wouldnt change or would go high. He thinks the electronics in that pedal or maybe my TB could be the cause.

Question is has anyone ever heard one going bad and doig this?

 

most likely the tb but there is a switch for the pedal but i have yet to hear one go bad

 

May i must add i have those accessory pedals GM offers. Those alluminum bs ones

 

Im thinking TB as well

 

88% TPS is the max I ever see, my idle is usually 18% but I saw 13% with an LS4 TB.

 

So your saying my TB is at normal?

 

No idea, but those #s are consistent with what i have logged.

 

After all the headaxhe of trying to figure everything out i finally solved the mystery after 2 years, my MAF sensor was screwed up, i changed it yesterday and done!!! No more idle problem no more running super rich, no more stalling, no more clouds of black smoke. Shes back to normal again!!! Thank the lord i finally got it fixed.

 

how did you diagnose?

 

Throttle position sensor. Get a real tech to do a live plot of it on a Tech2 or equivalent scan tool and you might see dead spotting or all together cut outs.

 

My girlfriends father is a mechanic for cars and motorcycles and he scanned the computer and did compression tests and searched for leaks (vacuum). My O2 sensors werent working correctly he then realized my throttle was all over the place when the O2 sensors were dead rich and not sweeping like they are supposed to. He said its either my throttle body or MAF sensor. So he cleaned them both out and noticed the car ran somewhat better for a little while. Then he said replace them and see. I took the chance with the MAF sensor first since it was cheaper. I slapped that in and perfect. Car hasnt ran like this in years.