vacuum leak question
Thread Starter
Racer
Joined: Nov 2008
Posts: 252
Likes: 0
From: Morehead KY
vacuum leak question
Will a vacuum leak keep your car from idling? I mean I fire up my car it starts but dont stay started for maybe a second, then shuts off, unless I give it gas. I have an 89 vette 6 speed, which i pulled the runners and plenum on to put permatex on the intake manifold bolts cause of a coolant leak. I didnt remove the intake manifold itself just retorqued and applied the permatex to the threads of the bolts, so i didnt fool with the timing of the vehicle or anything like that. Cars been sitting for awhile because of this but looking to start working on it here in bout 2 weeks again.
Thread Starter
Racer
Joined: Nov 2008
Posts: 252
Likes: 0
From: Morehead KY
Also I have edelbrock hi flo runners and intake manifold, and do here a sucking noise but dont know where it comes from cause i have to give the car gas to keep it running. Also i have a zz4 crate engine in my car, not the original motor. TPI has always caused me problems, i may need to switch to mini just to get rid of this tpi crap.
Le Mans Master
Joined: Jan 2003
Posts: 5,858
Likes: 7
From: Santa Maria CA
Disconnect the IAC connector on the throttle body and start the car. It's the square plug on the bottom passanger side of the thottle body with 4 wires. Unplug it and start the car. The idle should be high and stay high with the IAC disconnected.
To find vacuum leaks get a can of carb cleaner or starter fluid. Both work well. Use the straw nozzle and go around doing short sprays around the areas you took apart. Spray it on vacuum hoses, on the runner to intake joints where the gasket is, the mating line between the heads and the intake, the plenum to runner joints, thottle body etc. Spray around all of those areas. If there's a vacuum leak the engine will suck in the spray and you'll hear the idle change. Then you'll know you found the right spot.
To find vacuum leaks get a can of carb cleaner or starter fluid. Both work well. Use the straw nozzle and go around doing short sprays around the areas you took apart. Spray it on vacuum hoses, on the runner to intake joints where the gasket is, the mating line between the heads and the intake, the plenum to runner joints, thottle body etc. Spray around all of those areas. If there's a vacuum leak the engine will suck in the spray and you'll hear the idle change. Then you'll know you found the right spot.
