been trying to get my car to run properly for a couple weeks now but no luck. i have an 85 z28 with a 305 in it as well as a crane cam (454/455 lift i think). ive checked for vacuum leaks and have sealed them off but the car still wont idle right. the car will act like its running fine but either a- will stop idling after awhile or b- once i get it down the road, it will die when i put the brakes on and let off the gas. Ive looked all over on the internet to try and remedy this and from the way it looks i need to replace the stock torque convertor to a higher stall one? Or if there is another place for a really bad vacuum leak that im not looking (sprayed the intake and carb with cleaner). this is my wife and I's second car so i need this fixed yesterday. if any of you guys have had this problem or have any input, it is much appreciated. thanks

 

Have you tried plugging the PCV and brake booster vac hoses?
Carb or fuel inj?

 

Carb. I think it might be the step-up springs in the carb. The manual says that a cam may cause erratic idling with the stock ones, so I'm going to get some stiffer springs.

 

How can u be sure u got all the vac leaks? Have u taken a reading with a vac gauge? I had an awful idle, my vac was at only 5. Couldn't find a leak anywhere. It turned out to be on the bottom end of the intake manifold, which carb cleaner won't tell you. Swapped the manifold, put new gaskets and now I'm pulling 24 to 25 hg.

 

I guess i cant be for sure that i dont have one, but i found the problem to be a combination of stupid mistakes. overlooked the obvious reason being that the aftermarket carb wont run right with the stock distributor. also, getting the vac hoses in the right place since i dont have the emission system on it.

 

Def need a dizzy with vac advance. That will solve your stalling issue hopefully since the timing isn't changing when throttling up. However it won't affect anything at idle. Def invest in a vac gauge and hook it up to manifold vac during idle if ur pulling less than 20 u have a leak. Gauge is like 10 bucks. It saved me a ton plus u can tune ur carb with it

 

i will have to invest in one. thanks!