Engine running rough...fuel tank problem????
Thread Starter
Burning Brakes
Joined: Sep 2004
Posts: 843
Likes: 1
From: Carlisle PA
Engine running rough...fuel tank problem????
Our 99 coupe has recently started running rough when coming to at stop. Once stopped it will usually go back to normal idle. When accelerate again it will sometimes run rough for a few seconds then it will be fine again. It has never stalled out (yet).
I experimented and noticed that this occurred a lot more when the gas tank was 1/2 empty or more. I filled the tank with 93 octane and the problem diminished considerably.
That's what leads me to think it might have something to do with the gas tank/fuel system.
A couple of weeks ago I added a bottle of techron to the gas tank because of the infamous fuel gauge malfunction. Could that have damaged something in the gas tank? (sending unit or whatever)??
I saw that vettes actually have two tanks on either side of the car. Not sure how they work but I am thinking that somehow that might be a factor.
I am taking it to a mechanic this week and would like to have some "possible" causes of the problem to list of him so we don't waste time checking out things that are less likely to be the cause. At $75/hour labor that can get a little salty
Thanks
I experimented and noticed that this occurred a lot more when the gas tank was 1/2 empty or more. I filled the tank with 93 octane and the problem diminished considerably.
That's what leads me to think it might have something to do with the gas tank/fuel system.
A couple of weeks ago I added a bottle of techron to the gas tank because of the infamous fuel gauge malfunction. Could that have damaged something in the gas tank? (sending unit or whatever)??
I saw that vettes actually have two tanks on either side of the car. Not sure how they work but I am thinking that somehow that might be a factor.
I am taking it to a mechanic this week and would like to have some "possible" causes of the problem to list of him so we don't waste time checking out things that are less likely to be the cause. At $75/hour labor that can get a little salty
Thanks
Instructor
Joined: Oct 1999
Posts: 135
Likes: 0
From: San Diego, CA USA
most common cause is probably that the throttle body needs to be cleaned. Carbon build up causes the car to run rich and lowers the idle speed. The idle speed is then too low for the accessory load.
