I have a 350 TPI in a rod, MAP, painless harness, some aftermarket adjustable regulator (accel?)- think that's the important info.

I do have SES illuminated atfer about 15 sec of running and it stays on, but no codes...

THE ISSUE- Rail pressure is 45psi with vacuum line off and plugged, about 40 running at idle. It holds pressure fine when it's cold, but as soon as it is warm, the pressure drops off immedately with the key on after the pump shuts off. So , WTF?

I need one of the great experts on here to give me some guidance. I can start it hot, just have to turn the key right to start, but I'd like to fix this and figure out what is going on....

Thanks

 

The regulator and fuel pump chedck valve are simple devices. It's unlikely that they would be affected by heat. the name ACCEL doesn't inspire confidence. You may want to look at the regulator to see if the diaphrap might be having issues. The simple way to test the regulator is to block the return line and see if the pressure still drops off. The injectors are precision instruments and are affected by many things. You may want to perform an injector balance test to find if one is leaking. Or look at your plugs and see if one or more is especially dark, perhaps getting too much fuel from a leaking injector.