i rebuilt a 95 420a, have compression, spark and fuel, but the car will not fire this is the third time this has happened, the last time it was the cam key card that was faulty, no dice on this engine has spark on all 4 cylinders, even replaced the cam sensor seal what gives??? this has stumped 4 of my technicians and quite frankly myself if anyone can figure this out i will be ecstatic! please help folks!!!

Verify you're getting signal from the crank angle sensor - the car won't power the coil without it.

Fuel pump relay could also be a culprit - short the white red stripe wire in the ECU harness to ground - if the fuel pump does not run, it either has no power or the fuel pump relay is bad.

95's have known issues with the ECUs failing. Try a known good 95 ECU.

ecu was shot. it had fuel pressure and spark, but just wouldn't start and run.... changed the ecu and bam it ran! but why would the ecu be good coming in the shop, swap the motor and now it's bad? i removed it during the swap and reinstalled it after. i always ground the case when removing and out.

Originally posted by activeauto
but why would the ecu be good coming in the shop, swap the motor and now it's bad?

Murphy's Law.

I doubt it was anything you did. MAYBE the jousaling (sp?) or removal, but that's a long shot.

Or it could have been on its way out in the first place and some slight symptoms weren't noticed.