Ok I have tracked down the no start problem to the ecu (no start, spark etc checked icm, distributor, coil etc all good) bought a scanner innova 3140B connected up and couldn't communicate with ecu, also couldn't pull codes from ecu memory.
Had another ecu which when plugged in gave memory codes to the scanner (nothing relevant to ignition) and spark.when put back together got truck running again (1994 f150 4.9l 4x4)

So here is my question the number on the no good ecu in the truck is
F3TF-12A650-TB ANT1
The number on the ecu that works is
F5TF-12A650-ALA DOE0

Are these numbers critical/compatible or do I need to get another ecu with the right numbers and what are the differences?

Thanks in advance
Max

 

If the truck runs with it, use it.

 

That's perhaps a good recommendation if it's all he's got for an emergency road-side replacement, but it's certainly not optimal to run a PCM designed for a '95 460 in a '94 4.9. And yes, the DOE0 is for a 460.

Ideally you'd locate another ANT1, but any '94/5 4.9 donor with the same transmission type would be good enough. Note, if you've got a 5-speed, you can use a PCM from an automatic-equipped truck, but not vise-versa.

 

I would think a 460 computer wouldn't run a 4.9, but then again they are both batch fire. I wouldn't be so concerned with the numbers as long as it comes from a 4.9 truck with the same transmission.

 

Ok I had time to test drive the truck today (which is a 5 speed), not pulling properly from low revs or under load, have found another ecm with matching numbers so will have to wait for that to arrive down under via snail mail
Cheers
Max

 

Do yourself a favor and open it up before installing to make sure none of the 3 blue capacitors are leaking.

 

Ok ecu arrived today, opened it up as suggested and checked the caps, all is good, very clean inside. Fitted to truck and went for a drive, Happy to say I,ve got my good old workhorse back again running like a trooper
Thanks for the heads up on the ecu and the caps

Cheers
Max