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

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

RepairPal Verified
Average mileage: 173,500 (114,000–240,000)
Engines affected: 4.3L V6, 5.0L V8, 5.7L V8
8 model years affected: 1990, 1991, 1992, 1993, more1994, 1995, 1997, 1998
16 people reported this problem
6 people shared problem details
1994 Chevrolet 1500 Pickup- 4.3L V6194,000
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.
1991 Chevrolet 1500 Pickup- 5.0L V8148,000
higher than normal idle, just started looking for solution.
1994 Chevrolet 1500 Pickup- 5.7L V8195,000
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.
1990 Chevrolet 1500 Pickup- 5.7L V8114,000
Carbeureted so I need to hold the gas a bit to keep from stalling. Putting it on the scope soon.
1997 Chevrolet 1500 Pickup- 5.7L V8240,000
Idle at 2000 rpm.after warm, until come to a stop then it will idle down?
Related Items:
could it be under the throttle body,i have no coolant leaking.just a bad vacume leak
Truck runs great when driving down the road and idles smooth for a couple minutes after coming...
truck had no power in passing gear and a shudder in the shifting so i changed the transmission...
how do i know when the throttle body unit is not working well and when do i have to replace it...

Related Content