1500 Pickup

Highter Than Normal Idle Due to Vacuum Leak on Chevrolet 1500 Pickup

Problem Description and Possible Solution

The throttle body gasket may develop a vacuum leak which may result in a higher than normal engine idle. Failed gaskets will require replacement.

Problem Data
RepairPal Verified
Average mileage: 160,549 (19,440–260,000)
Engines affected: 4.3L V6, 5.0L V8, 5.7L V8
8 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1997, 1998
61 people reported this problem
Viewing 1 - 12 of 12 comments
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.
It would start great no problem but when I hit the break it would die and even when I throw it in reverse it dies. I had about 4 guys look at it and they said its vacuum leak somewhere so I replaced it and it fixed my problem
Engine is hard to start,gotta pump the gas and then the idle will run up then down and stalls at times,replaced fuel filter and looked for vaccine leaks,still not fixed
Carbeureted so I need to hold the gas a bit to keep from stalling. Putting it on the scope soon.
Starts hard turns over slow and recently started randomly shutting off when I stop at a light or stop sign... Check engine is on code 32 33