93 454 TBI - no start after head gasket replacement

[LOTW29]

We have combed through forums for hours, we are at the end of what we can come up so any help is appreciated; but here's what we did.
Truck: 1993 K3500 454 TBI Automatic Trans
(Recently purchased from the third owner and have been doing updates, upgrades and improvements to get it to where we want to).

Bottom line up front: crank, spark, fuel, no alternating injector pulses during cranking.

Head gasket leak led to an overheat and it busted open the plastic side tank cooler of the radiator. It DID run afterwards as we had to move it around the yard and into he garage (briefly where it didn't get up to operating temp).

We figured out it was the head gasket so we pulled the heads, had them resurfaced and manually ported them nicely (enough) with a die grinder.
Replaced the radiator, and some other accessory parts.

Got everything buttoned up together. Cranked, spark, no fuel.
Turns out we were just low on fuel. Added 5 gallons, still no start.
We realize we weren't getting the alternating injector pulse when cranking but we get the initial shot when we turn the key to on.
Utilized injector light testers, no alternating light flashes. Replaced the oil pressure switch, no change in results.

So after we tested and checked grounds, we replaced the ICM on the distributor.
At one point we got very rapid and random firings of the injectors while NOT cranking.

Replaced the PCM utilizing the same PROM with jet performance chip. Replace the ICM with another one!
For the first time we cranked, saw alternating firing of injectors and paused to button everything up to hopefully fire off.
No dice....

We've tested continuity from the TPS, ICM, etc from there to the PCM(ECM). Utilized dielectric grease, checked connections, and yes of course we've checked fuses and the fuel relay. We have even hot wired the fuel pump to ensure the pump is running with it cranking.

Are we to believe the PROM is bad or fried from a short?

Thanks! (Please HALP)

 

[Cadillacmak]

Have you tested fuel pressure to make sure the regulator didn't die?

 

[LOTW29]

Have you tested fuel pressure to make sure the regulator didn't die?

No, but it's a new pump (within last 10 miles). Issue appears to be that the injectors aren't firing (led injector test light) not lighting except for initial pulse.

 

[Schurkey]

You HAVE spark, you have fuel pressure, but no injector pulse when checked with a 'noid light?

First Guess would be a popped injector fuse, but you say you've checked them. Do the injectors have system voltage when the key is turned to "Run"?

Connect a scan tool, make sure the TPS is reading correctly. If the TPS is somehow showing a WFO throttle signal, the computer will go into "clear flood" mode with little or no injector spray.

If that's OK, look for faulty wiring between the ground side of the injectors, and the computer.

 

[LOTW29]

They have voltage for that first few seconds when the initial pulse of the injectors fires for the pre-crank.
We've checked the new TPS and the voltage is correct in it's respective positions

 

[Schurkey]

Injectors are supposed to have power whenever the key is turned to "Run". They spray fuel when the computer grounds them.

If they don't have power except intermittently, you need to probe the power supply circuitry including the ignition switch.

 

[LOTW29]

Correction: 12v with key on at injectors. 9v at injectors whike cranking. Just no pulsing while cranking.

 

[Schurkey]

Correction: 12v with key on at injectors. 9v at injectors whike cranking. Just no pulsing while cranking.

look for faulty wiring between the ground side of the injectors, and the computer.

And...maybe...a faulty ignition module.

Does the scan tool show RPM when cranking?

 

[LOTW29]

ICM has been changed twice

 

[LOTW29]

OBDI. Not utilizing any scan tools