1995 Gmc Topkick Gas Stalls On Decell

1995 topkick · December 9, 2007

well I purchased a very low mile very clean 50,000 gmc top kick flat bed tow truck and have had an interminnant problem with stalling on decellration like when taking an off ramp as soon as I let go of gas pedel turns off, will idle perfect all day just when I let go of gas on decell

truck has 366 gas tbi engine with 5spd manual trans,

I have already changed in order

fuel filter

fuel pump

fuel pump relay

rotor cap wires

igntion module

coil

at this spoint I gave up and brought it to my local chevy med duty truck dealer

they changed

ecm computer

oil pressure switch

they also told me I had a loose ground on fuel pump?? they fixed

I have spent over 2k trying to fix the truck and am very frustrated well I got it back two days ago and today it stated agian check engine light came on and trouble stated again only when letting go of gas dies interestingly when I shut it down the check engine light goes out and problem seems gone until light returns. any thoughts help please ow it already has freash gas and and lucas fuel stabilzer in it I am ready to hit with a hammer help does any one think it could be the throttle position switch? any ideas I am going broke over here???

tomcatinva · December 13, 2007

1995 TopKick

I'm no auto tech but this has worked on a Buick and a Ponitac that I personally know of and I am sure it has worked on other TBI engines. Try cleaning out the Throttle Body itself, I am sure that there are cleaners for it but I personally used gumout carb cleaner on the Ponitac (it was a Fiero). Mine was so dirty that when I looked at it the inside of the trottle body it was the color of the asphalt and when I had the defog on and had to decelerate the car would stall. The Buick would start to loose power after running for a while with the AC on then you would have to pull over let it sit awhile turn the AC off then restart the car leaving the AC off. With both vehicles after cleaning the throttle body they ran like champs. On the Pontiac I would clean the trottle body at least once a year just to stay on top of it. And by the way the dealer (nothing against them) told me it was the computer.

I hope that helps, Good Luck...

TomCat in VA...