Note On Intermittents
Backprobe ECM terminal D9 with a voltmeter to ground. With key on, observe voltmeter. Voltmeter should read battery voltage for 2 seconds and drop to zero. If voltmeter stays at battery voltage for longer than 2 seconds, check for fuel pump relay contacts sticking. Repeat test several times.
Continue backprobing D9 to ground and crank engine. Voltage should drop immediately to zero when cranking stops. If not, check oil pressure switch for sticking contacts.