Hi Guys,
I have a '65 Coupe that I dropped a performance 302 into. I'm having a weird issue with the car in that when I drive it now it runs like a top. But, once I shut it off, if it's hot it will not restart until it cools down. The engine will crank but it will not fire. I dropped a 4 core aluminum rad into it so the engine never really gets over about 170F. Has anyone experienced this or does anyone know the cause to this problem? I converted it to electronic ignition with the Accel Flamethrower coil and am wondering if they might be the issue? It just seems weird that it starts perfect when cold but acts up when hot??
Thanks

 

Is any part of the fuel line in contact with the block or transmission where it shouldn't be? Usually these kinds of issues are vapor lock related. However, a new or good starter makes a world of difference for hot starting. Mine used to be very temperamental, after a new starter it is much better but still has vapor lock. If you have room under your hood maybe consider a phenolic (non metal) carb spacer? Also, check your timing just to be sure. I was fiddling with my timing one day, thinking that I had it mastered, until I went to home depot and it wouldnt re start. Made a drive the next day after retarding the timing a bit and it was much better.

 

Nothing from the fuel system is in contact with the block or intake where it shouldn't be. I'm running an Edelbrock RPM Air Gap intake so that should also help with spacing from the heat. I do not have room to run a carb spacer as my air cleaner nut is mm away from rubbing the underside of the hood as it is. I can smell alot of gas when this happens so I know it's getting fuel and the starter cranks good the entire time so I'm pretty sure that is not the issue as well. It's definately a weird problem that I'd love to get to the bottom of because it's not much fun driving the car when I live in constant fear of it dying at a traffic light or me shutting it off at a bad location.

 

Actually this is not such a weird problem. Its probably caused by percolation of the fuel out of your fuel bowl and into the IM. Percolation is caused by the heat soak of the engine being passed into the carb housing which causes the fuel in the float bowl to boil over into the intake manifold. To diagnose it do the following:
next time you've driven the car for a fair piece and shut it down, let it sit for 5 minutes and then open the hood. Pull the air cleaner lid and look down the carb throat. If you smell a heavy raw fuel smell or see fuel burbling out of the vents or venturi - its percolating. Also look for a sticking choke plate as well. If it's indeed percolating, you can pull the top of the carb and adjust the float level but frankly in my experience, the only way to fix it is a non metallic spacer.

 

It dies at traffic lights? Like jlg said things can be done to make it better, but usually if you don't run a non metallic spacer its pretty hard to eliminate. Do you have a choke tube installed? Sometimes removing that helps

 

Thanks for the info jlg, I'll check that out next time it happens and see about fitting a spacer in there somewhere if need be. And guitarman it hasn't died at a traffic light yet but due to the hot starting issue I'm VERY paranoid about it happening now.