OK, I've been reading these posts as I've been working on this van for the past few weeks. Now I'm asking for help...

1994 B250 5.2 purchased non-running seller says outta gas, I assumed it needed a fuel pump.

I installed a fuel pump, started intermittently and ran great once started.

Installed fuel pump relay, no change.

Noticed no CEL when I turned key but would flash and click the relay after a few minutes with the key on.
Installed a used ECM, ran perfect for 2-3 weeks.

Engine dies shortly after starting 2x and restarts. Next day no start, no fuel. Testing, I blow fuse-able link to ASD and Fuel relay (dont know which 1 it is so I make a new 1.) Drop tank to test for power to tank, tests good. plug it back in, runs great.

I'm guessing that I have a bad ground, van is fairly rusty underneath. Cannot find fuel pump ground, figure on running a new 1 and splicing it. If the pump is bad I'm thinking it'd not come and go?

Now the big thing. As I trouble shoot and am buttoning everything else up, I accidentally arc the + & - battery terminals. This was just for an instant, but now it won't start again. I did notice the CEL light once again does NOT light when the key is turned from the off to the run or start position.
What did I do? Fry the new ECM? Burn up something else? Fuses appear to be all good.

I'm generally pretty handy, this van is beating me up! Help???

 

I think you need to check all the fusible links again. The ecm on my '89 has it's own.

Also add an engine to frame ground strap/cable, and make sure the battery to engine and firewall straps are polished to silver and tight.

The ASD relay is activated switched by ground from the computer.

On my '89 the ecm gets it's ground at the foot of the Coil. See if wiggling the ECM wires with the ignition on causes the relays to click.

Good luck

 

Thanks,

I checked the 4 wires going into the ASD & fuel relays

Red constant power
Blue Keyed power
small blue w/ yellow keyed power
green wires No power

I believe the grn/Blk on the fuel relay goes to the pump
I'm unsure what the grn/org on the ASD does exactly???

No CEL when I turn key to on or start.
No spark
&
No fuel prime signal.

As far as testing the ECM/PCM either power or ground...
Anybody have a Wiring schematic or know which pins to check?
Is the grn/blk & grn/org the same at the pcm?

 

This BL/Y wire is supposed to be grounded by the PCM when the key is turned on. It sounds like the PCM isn't grounding the wire to energize the relay. The green wire is the relay output and goes to the pump.

 

I tried manually grounding the bl/y wire and this does cause the relays to click. Still no start & no CEL, what should I look for next?
Grounds, power to certain circuit of PCM, ???

What causes CEL to light up when starting? I know that before with a faulty PCM it had no CEL and nor did it start.

 

Did you inspect all of the fusible links as landyacht318 suggested?

 

I had thought that I did... So this time i took a lot of the electrical tape off of the wiring loom. I did find that the 1 fuse-able link ran the opposite direction, and appears to power the circuit I was having challenges with.

Van now runs, went to check 1 last time prior to reinstalling the fuel cell... no pump...
checked and have power at the relay...
Wiggle the plug and it runs, wiggle some more it cuts the pump.

I have the technology to replace the plug. Is this common with these vans? And is $35 the dealer wants for the plug within reason?

Thanks for the suggestions guys!