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I am seeking possible repair advice. I do not know all the details of the build. Just what I have uncovered while working on the car. Its a 306, lunati high lift cam, ported e7 heads, edelbrock performer rpm intake mani, with a 650 edelbrock carb. has a MSD dist, msd 6 AL (I think), and a MSD blaster 3 coil.

Issue: the car started doing this about 2 months ago. I have owned it for 3 years and have not had this issue in the past. So the build is not the problem. Once the car warms up, if I give it a rev (either stationary or moving) once the RPM's drop it will die.

So, say I rev it while stationary to 2500-3k+ as soon as it revs down it will just stumble and die. Or , if I am on the interstate running @ 2300ish RPM's and take it out of gear to slow down, it will die. The only way to keep it alive is to feather the gas once you take it out of gear. Once you feather it for 3-5 seconds then it returns to idle and runs fine. It only does this when warm. When its cold it does not. Any ideas??

 

If the choke is working correctly, then the car sounds to be leaning out at idle once warm. The choke keeps it idling higher when cold.

So many times on carbed engines, one just needs to go back to basics and readjust all the tuneup settings. I never assume anything is set right. Start from the beginning as if the carb, distributor, and plugs are all new and ready to install. Set the properly and go from there.

 

Thanks for the reply.

I will give this a test tomorow and report back.

 

what is your timing at idle with the distributor vacuum disconnected and connected?

if it is less than 12 adv the dist to 12.

disconnect all vacuum to carb and intake. spray brake cleaner gently with long nozzle to look for leaks.

turn your fuel mix screws both ways equally until it reaches the highest idle.

reset idle speed. if the screws have no affect the idle circuit might be plugged.

check gas level in carb if it's a holley. it should be just below the inspection holes.

an idle dash pot will help.

 

As the gas gets crappier and has more ethanol, Things run leaner.
Also you may have just a little water collected in the float bowls.
Just a thought