Idle and cruising acceleration problems.
Thread Starter
Race Director
Joined: Jul 2001
Posts: 13,710
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From: So Cal
Idle and cruising acceleration problems.
I have read and searched, but have come up with no real answers to what problems I am experiencing. I have a 94 LT1 auto with about 95k and it has been great until now. It starts and idles fine, and drives great until the engine gets to operating temps and then the problems start. Examples of the problems I am experiencing are, if I am cruising at any speed and give the accelerator more gas it seems to struggle to burn the gas and kind of chugs, but if I floor the pedal it seems to be fine and powers up with little problems. The other thing that is happening is when the engine is warm, and I stop at a light, the idle will start going crazy, from 500 rpm up to 2k with the brake on and the car in drive. If I put the car in neutral the idle seems to be ok. These problems only happen after the car is at full running temps, and after it has been driven over 15 - 20 minutes. I am not really sure where to start trouble shooting the problem, I am thinking it may be old hoses, and a vacuum leak because of it having to be hot, but the idle thing in gear with the brake on makes me worry that it is a tranny problem as well. It is scary having 300hp surging at a stop light with cars in front of you. Any info or help would be great, and thank you.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: Idle and cruising acceleration problems. (morphious)
I assume you are cruzin at relatively low rpm; next time out try pulling it into say 3rd gear and see if it still lags with light throttle.
If not, check out the TPS resistance as you slowly open the throttle from idle position.
If you see any jumpyness, replace the TSP.
If not pull the IAC and clean it.
If not, check out the TPS resistance as you slowly open the throttle from idle position.
If you see any jumpyness, replace the TSP.
If not pull the IAC and clean it.
Burning Brakes
Joined: Nov 2002
Posts: 807
Likes: 21
From: Los Altos CA
Re: Idle and cruising acceleration problems. (morphious)
It could be a problem with the Manifold air temperature sensor, perhaps the water temperature sensor. If the engine computer gets a bad temperature value, it can cause it to get the wrong fuel flow (injector pulse width).
Burning Brakes
Joined: May 2001
Posts: 790
Likes: 2
Re: Idle and cruising acceleration problems. (johnandblairspolovet)
It seems to be okay in nuetral, but not in gear? Think that's key. I know there is adjustment for the transmission and throttle. TV cable? and that transmission shift points are determined by this adjustment. I think you should start there. I'm going home shortly and will look in my factory manuals. I have a 92, but they are very similar.
Are you throwing any codes?
Are you throwing any codes?
