pwneal57

When car has been sitting in sun and temperature gauge is above 100F, the car cranks engine properly but some relay module is not firing the ignition. Normally, ignition fires after about 3 seconds when whatever module fires the ignition. Cranking the starter after this time period does not lead to ignition firing. I have changed the ignition module mounted on passenger side strut top previously. I can go all winter with no problem but summer in Florida is here and car interior temperature gauge shows140F.

motoxxxman

it's the #1 most common failure in 88-91 preludes: the main relay. it's under the dash on the driver's side. it powers the fuel pump, ecu, injectors, and coil. what you're experiencing is exactly what the symptoms of a bad main relay are.

P.S. parts stores typically call it the fuel pump relay.