grim0404

i just built this 350ci bored 60 over 400 crank with compcams extreme
torqer 2 edlebrock intake 750cfm edebrock performer carb the engine starts up at hhigh idle then when i let of the throttle the engine dies i thought it was spark so i installed a msd 6a now i get a better spark but still same problem pls help what r possbilities

swingline

sounds like maybe a vacuum leak or carb problem. hook up a vacuum gauge

bobss396

I agree with a vacuum leak. With the air cleaner off and the car at idle, put your hand over the top of the carb air horn. If the idle picks up, you have a vacuum leak.

Check all hoses, also for something open on the carb or manifold. If no luck, spray some carb cleaner around the base of the carb, all linkage and spacers if any. Next will be where the manifold meets the heads, try not to get the engine too hot or switch to a spray bottle of water. I'm not big on spraying volatile stuff on hot cylinder heads.

If it is the manifold, it could be as simple as a re-torque. If that doesn't do it, you'll have to pull the manifold, but try to isolate where the leak is. If you get that far, let us know and we'll be better equipped to come up with a solution.

Bob

grim0404

hey thanx guys i tryed that and come to findout it was the rockers where a little to tight now the thing runs like a monster a lot of power but what i did notice was that morning startup great oil pressure but once it warms up i lose pressure at idle while rpms are high great oil pressure tried replacing oil with 20 50 but still same added some synthetic after break in and same what could be???