Ok slowly but surely getting the old coronet back to great running condition, she runs good when im on the gas, but if i let off the gas at any stop she dies. It only does this when warm though, when its cold will idle just fine then i drive a block and she starts dying on me. I assume a vacuum leak but do not have a vacuum gauge to check right now. I wen through all the hoses and checked them for cracks or holes but most hoses are new and they all looked ok. I started messing with the choke and noticed its really touchy, just a millimeter change in the choke plate and it completely changes idle, seems a little too touchy? sound like choke problem or vacuum problem?

 

I'm thinking leak. If you take a spray can of brake cleaner or other flammable spray, small squirts where manifold meets head, or any suspected area, will draw it in ignite it and raise R.P.M.

 

does it have power brakes ?? Try blocking the vacuum line to the intake manifold

 

ok just spent the whole night resealing intake and cleaned out the carb. really well and now looks like shes idling again. thanks for the replies