Monday, October 24, 2011

Car doesn't idle, but drives perfectly. What do I do?

I have a Chevy 383 stroker with a Edelbrock 650cfm thunder series carb. MSD HEI distributer running proper spark plugs. I tuned in the car and it ran wonderfully for about a half hour. Sounded great, heard the cam in it and everything. Took it out for a drive and came home and it didn't idle worth a ****. So I ended up trying to retune it and that didn't help any. I asked on here and someone said I fouled my plugs. So I got new spark plugs and that didn't help any. So I changed my distributer cap and rotor, that didn't help. I rebuilt the carb since I was hearing a hissing sound that was louder than it used to be, that didn't help.



Now smaller details.



I have a manual choke, it runs fine with the choke about half way out. Sounds good and everything, so that's what is making me think it's a vacuum leak now.

If I leave the choke half way out and I start to accelerate, the car starts running like **** and sputtering and has no *** to it, push the choke back in and it gets it all back and it's acting like a turbo or something kicking in. It's more like it's getting the proper amount of air.

Now, I can get the car to idle but the rpm is in the 1700 range, before I had it about 900 when it was running smooth before the spark plug change. And with the idle at 1700, it sounds like **** too until I start giving it some throttle.



I attempted to change the vacuum advance canister today and that didn't work out since I couldn't figure out how to get the canister out. I got the 2 screws out that hold it in, but the little lever part wouldn't push down far enough since it was hitting the base of the distributer, not sure if there is soemthing else I have to take off, I only removed the cap and rotor to get to it.



I checked all hoses, replaced the PCV hose and the PCV valve itself. The seal that the valve goes into isn't tight against the valve cover but the hissing sound is coming from the passenger side of the car, somewhere near the back maybe. I sprayed carb cleaner at every sealing surface back there to listen for a idle change and I never heard one. And... it seems that when I leave the choke in, the car sometimes will idle fine at a traffic light or something, but then suddenly it just takes a **** and almost dies on me, I have to smack the gas pedal and pull the choke out part way if the light decides to take a while.



Has a thumpr series cam, 479 intake, 465 exhaust. And most people ask what car it's in, it's in a 94 Camaro, so that's not gonna help much but I told you anyway. So I know the car idles because it has idled before, the car still hauls *** and can kick the **** out of cars on the highway like it always has been able to, but it just won't idle reliably.Car doesn't idle, but drives perfectly. What do I do?since it gets better with the choke active, id bet that you have a lean mixture issue. take both mixture screws and turn them all the way in, now back them out 2 and a half turns, see if that does it.

because you also mention a hissing, look EVERY where for a vacuum line that is off, or a cracked intake even. i hate looking for a vacuum leak, it can be any thing. you just might try the old trick, with it running, spray carb cleaner around any point where you have a gasket on the intake, if the rpm picks up, note the location and replace that gasket. it could be a warped manifold too.Car doesn't idle, but drives perfectly. What do I do?sounds like your low speed jet, could be cloggedor restrictedCar doesn't idle, but drives perfectly. What do I do?ck basic compression , invest in a heat gun and see if all header tubes or manifold coming out of head are hot and same temp look for low temp you may have vacuum leak or other problem if temp is low , do with choke off and whatever is the lowest idle without dying .