baffled

[landrea]

On my 95 tow truck we have been throwing parts at for 3 weeks now and it still won't run.Drove home one day,came out 2 hours later and it would only start and die.I put on a new PMD (always in stock in my garage)still no start,installed new inj. pump(always in stock in my garage) still no good installed new PCM (not stocked in my garage had to get from the dealer)still no start.I borrowed a 95 service book and performed the checks and was dumfounded.I was embarassed but had my tow truck towed to the dealer.After 2 days of checking we find no problem but it still won't start,now here's where it scares me, after installing yet another INJ pump we find no fuel comming out of the injector lines yet there's plenty of fuel and pressure comming in and the shut off solenoid is working.Even if electrical was hawire if the shut off sol. opens and the engine cranks shouldn't I get fuel out of the injector lines?

[markrinker]

Not sure on your question - I'll let someone that is answer it.

However, I think you are close to the source of your problem. Are fuses for your pump clean and good? My '94 fuseboxes/fuses are very problematic, corrosion, loose connectors, melted fuses have been the root cause of many mysterious no start situations.

[landrea]

All fuses are good and all grounds clean and tight.BAFFLED STILL #@*?

[rameye]

If it was mechanical I'd agree with you.. but this pump is all electric.....gotta gremlin..you get no fuel...pretty sure anyway.

I would start with the basics..

Is there fuel to the inj pump?...loosen the line and check.
Is fuel bypassing and going to the returns (Ithink this verifies the solenoid is open)

It has to be obvious...I always crew nyself and assume the big obvious things are OK. Usually after some head banging and knashing of teeth I see what I missed.

good luck

[charliepeterson]

Try disconnecting the PMD. Probe terminal "A" while cranking the engine. You're looking for 1.2 volts. If no, the circuit is nfg or the connection at the PCM is bad "BD13". This is the Fuel Inject Control circuit.
If yes, you're into the ground circuit. Probe terminal "B" at the PMD, with the test light on B+. If no the circuit is open or bad connection on "PD2" at the PCM, this is the closure circuit. If it lights than go to pin "C" with the test light grounded. If it lights then the IP is dead. If not the circuit is open going to the 20amp "fuel sol" fuse under the hood.

Over time the bulkhead connector under the A/C accumulator can give you trouble. Of course the tank level has been checked and the fuel filter too? The last off the wall thing to look at is a plugged fuel return circuit. One last thing, does the "SES" light come on when the key is turned on? The PCM needs this circuit to operate correctly.

This issue really sounds like an electrical problem.