My 1990 chevy stepside 1500 with a 305, starts when cold then doesnt start when hot. I replaced the distributor cap and button, and plugs.
Do you have fuel injection and if so, what type in 1990? Carburetor? It may be the float needs to be replaced. It sounds like fuel starvation, and what happens when it is hot. Not enough fuel gets to the reserve or stays in the reserve when running then shut off. If it is an EFI, you may have a slight air leek somewhere and the electronic controls will not send a message to send spark when hot due to improper air/gas mixture. The system can be checked for leaks and fuel pressure if you need.
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