I have a 1982 Z/28 with a 305 V8 with TBI(Crossfire). I am having an issue with the vehicle when the engine is hot. If the vehicle sits for 45 minutes to one hour after being driven, the vehicle will restart but I can barely keep it running. When the engine is cold the vehicle starts and runs just fine. If I let the hot engine cool for say 2 to 3 hours the vehicle again starts and runs just fine. Any thoughts or suggestions regarding this would be greatly appreciated.

 

Could be a number of things. It's hard to say. Could be your spark control module (if your car has one), Fuel injectors failing, bad battery cables.

 

could check the CTS-plugs on the original co-axial style plug are known to crumble and fall apart giving false coolant temp signal to ECM.Corroded electrical connections that increase resistance when cold is another possible cause(reducing volts to fuel pump,ETC.)