I am having an unexplanible problem. Background: 730 ecm with 355, do my own tuning. Car ran and drove fine and gave me no trouble. Parked car and went to drive it three days later. Will not start.

Starter engages and turns rotating assembly. There is a 2 second prime before I engage starter. Fuel pressure goes to normal, than drops and fuel pump does not turn on untill I turn key back and then go to start it again, primes engine to correct psi, then turns off.

I get no spark when trying to turn engine over. I swapped to three different 70 ecms, no avail. There is gas in the tank. Everything is hooked up /wired correctly. No blown fuses. Changed ful pump relay out to a new one.

Could it be ignition module or the oil press sensor? Why is it doing this all of the sudden?

 

Could be ignition module or pickup coil. The ECM won't turn on the fuel pump until it receives reference pulses from the ignition module. If you cranked it long enough the oil pressure switch should eventually turn on the fuel pump.

 

It does sound like your ignition module....

 

It was the ignition coil module. I checked the resistance (ohm readings) on the pickup coil and all was well. Checked the voltage at the coil and it's resistance and all was well. Changed the module and it started right up. Scanner never picked up an RPM while cranking over.

I should have caught on to this earlier, gas mileage was out of the ordinary and it would "miss" for a second a few times a week. Nothing remotly serious happened untill today.