The throttle body gasket may develop a vacuum leak which may result in a higher than normal engine idle. Failed gaskets will require replacement.
Average mileage: 155,956 (19,440–260,000)
Engines affected: 4.3L V6, 5.0L V8, 5.7L V8
28 people reported this problem
Had to drive 30 miles home after the truck was sitting for 8hrs.Sounded normal at start up idle. It's an automatic tranny.Well when I accelerated,the engine wouldn't shift from 1st to 2nd gear normally instead it shifted late and finally after high rpm's and whinning it would jolt into 2nd gear,felt like I was about to drop the drive shaft,the "check engine" light also came on.For the duration of the drive it repeated that huge jolt occurance from 1st to 2nd at every light. Got home and an hour later it drove normal and I didn't experience that problem again and that was 6 hrs ago.Go figure.Checked for T-fluid leaks ..none and the level was good too.Thought the tranny was in the 1st stages of going out but a mechanic friend said sounds like a vacuum leak or the vacuum actuator bad.I'll check all vacuum lines in the morning.Anyone's ideas or thoughts would be appreciated,thanks.
engine idles too fast, wasting fuel, and making it unsafe at slow speeds, because i have to have my foot on the brake. carb cleaner sprayed at the base of the throttle body, when idling, is sucked through, causing the enging to bog down for a short time. I suspect a gasket failure.
This problem has not been fixed yet.
I start my engine in the morning, idle goes down but in 5mins. it's back up and then shut down, after that it's hard to start and keep running,after lifting one of the injection wire to keep from flooding out, until it start,I do this for a few min. and then it may start correctly. i really don't know the real problem, but it's a serious problem now for me, now Tran don't want to back up.