I have a struggle. I have read a good bit on the vaccum canister and fuel issues, trying to determine what is going on with my engine. I have swapped in a 350 a couple years ago and am running a mechanical fuel pump, which is in an 85 z28. I have also removed the computer. The motor runs well, as I have been daily driving it for 2 years now. Last summer I had no issues with heat and the engine bogging down. Sometimes it is hard to start in the summer, after it has been driven for a bit, but once started it was fine. As it has warmed up this spring, I have started having an issue when the temperature 80 or above. The car is fine until it sits idling or is turned off. If idling it will eventually bog out. When I start driving it has no power for a bit, but after a bit the engine returns to normal and has the power it needs. I do have a non-metal spacer between the carb and the manifold, but it is only about 3/8 of an inch. I did replace all the vacuum lines in the engine bay when I did the swap. Thanks for any help or ideas.

 

One other note, I am running a Edelbrock 1406 carb.

 

Sounds pretty straightforward ordinary usual and expected.

The fuel reaching the carb is HOT at those times.

Insulate your fuel pump from the block. That's where the heat is coming from. Something as simple as, use 2 FP gaskets instead of just one. If you're not using a gasket at all (FP bolted straight up with just some RTV or something, no gasket at all) then that's the root cause.

You could even get yourself one of these. https://www.cantonracingproducts.com...ion&key=85-000 Probably not necessary, and kinda $$$$ besides, but just in case...

 

Thanks kingdom. I have a FP gasket on, think I will try the link. Will let you know.

 

Is your mechanical pump the type with a return line?

 

Yes mine has a return line. It runs down the passenger frame rail and I was able to move them a little further away from the header on that side.