94 Explorer - died while driving, now crank no start, no fuel pump prime, no CEL on dash when trying to start

[JakeRenshaw89]

Hey all!

I’ve searched through the forum and can’t quite seem to find a solution here. Having an issue with my 1994 Ford Explorer. A week or so ago it just decided to die on me while driving. I got it to the side and tried to start it but did not hear the fuel pump prime. Checked the relay and it’s good (both the PCM and Fuel Pump Relay) so figured the fuel pump crapped out. Just finished changing the fuel pump and fuel filter and still no prime. Just cranks and no prime.

I also just noticed I’m also not getting a CEL when trying to start it where I think it should be there. So now I’m thinking maybe the PCM went bad?

What do you guys think? Thanks in advance!

 

[Project91Jp]

I'm going through the same thing right now. I think it's your crankshaft position sensor. But before buying one, check your inertia switch. It's on the passenger side near the hump. You might have to pull back some carpet to get to it.

Check this out in the mean time.

How to: - Ford Explorer Engine No Start Procedure

This procedure diagnoses a No Start engine problem. The procedure is based on information from the Ford Service Manual and my personal experience. The numbered steps should be performed in the order listed. 1. Does "THEFT" blink rapidly with ignition key in Off, On or Start? Yes: Verify key...

www.explorerforum.com

 

[JakeRenshaw89]

I'm going through the same thing right now. I think it's your crankshaft position sensor. But before buying one, check your inertia switch. It's on the passenger side near the hump. You might have to pull back some carpet to get to it.

Check this out in the mean time.

How to: - Ford Explorer Engine No Start Procedure

This procedure diagnoses a No Start engine problem. The procedure is based on information from the Ford Service Manual and my personal experience. The numbered steps should be performed in the order listed. 1. Does "THEFT" blink rapidly with ignition key in Off, On or Start? Yes: Verify key...

www.explorerforum.com

Thanks! I found that thread a day or so ago and still need to read through it a bit more. I did already check the inertia switch and I am getting the correct readings there. Would a CPS fail out of nowhere while driving? Would a PCM fail out of nowhere while driving? Seems odd to me but maybe.

 

[Project91Jp]

I can't say. This is my first rodeo. Did you test the pump before installing? I had a pump have a loose connection.

 

[JakeRenshaw89]

I can't say. This is my first rodeo. Did you test the pump before installing? I had a pump have a loose connection.

I admit to faults as I did not check the pump before installing! I suppose I could still go that route but my lack of a check engine light all of a sudden is what has got me thinking it’s something else and more PCM related. The car did not jerk/stutter when it died, it just all of a sudden died out of nowhere and now no CEL at all and no fuel pump prime but relays checked out good.

Thanks for your help man, much appreciated.

 

[massacre]

Check your ECM relay, in fuse box under hood pass side

 

[Josh P]

Check your ECM relay, in fuse box under hood pass side

I'm thinking the ecm lost power as well. I think there's a fuse or 2 that needs checked.

 

[massacre]

I'm thinking the ecm lost power as well. I think there's a fuse or 2 that needs checked.

I had this same issue, crank/no start, no fuel pump prime, no CEL while cranking. Truck died on me several times while running as well. I removed the fuel pump relay, and used a power probe to send 12v to the fuel pump. Fuel pump ran. Then looked into the circuit- fuel pump relay runs off ECM relay. Replaced ECM relay and CEL came back and truck has been running fine ever since.

 

[Josh P]

I had this same issue, crank/no start, no fuel pump prime, no CEL while cranking. Truck died on me several times while running as well. I removed the fuel pump relay, and used a power probe to send 12v to the fuel pump. Fuel pump ran. Then looked into the circuit- fuel pump relay runs off ECM relay. Replaced ECM relay and CEL came back and truck has been running fine ever since.

It's happened to my Aerostar van as well.

 

[410Fortune]

Sounds like


Eec fuse or
Eec relay

 

[JakeRenshaw89]

Sounds like


Eec fuse or
Eec relay

Just rechecked all the fuses and relays and they are good. I did not check the DIODE fuses, could that be an issue?

 

[Josh P]

Just rechecked all the fuses and relays and they are good. I did not check the DIODE fuses, could that be an issue?

do other circuits have power?

 

[JakeRenshaw89]

do other circuits have power?

Hey Josh P. I’m still coming up to speed on the electrical side of things with this car (all cars for that matter), which other circuits are you referring to?

 

[Josh P]

Hey Josh P. I’m still coming up to speed on the electrical side of things with this car (all cars for that matter), which other circuits are you referring to?

I'm just curious if anything else died at the same time, radio, any lights, power windows, locks, etc. As far as the ecm power diode if you turn your key on and if the ECM Power Relay clicks the Diode is good.

 

[410Fortune]

The pcm relay turns on with the ignition Switch in your steering column
The pcm relay energizes the pcm
Which then turns on (primes) the fuel
Pump via the fuel Pump Relay fuse and inertia switch.
You need to check for battery power and then switched ignition power at the eec relay as well as a good ground
This would
Rule out the ignition switch pcm fuse and relay as the issues

You can check for power at the pcm power feed wires from
Relay as well but we can get into that after these first checks are done

How did you “check” the relays? If the eec (pcm) relay does not “Click” when you turn the key then you have either a bad ignition switch or wiring to or from or a bad fuse or the pcm relay itself is bad

 

[JakeRenshaw89]

The pcm relay turns on with the ignition Switch in your steering column
The pcm relay energizes the pcm
Which then turns on (primes) the fuel
Pump via the fuel Pump Relay fuse and inertia switch.
You need to check for battery power and then switched ignition power at the eec relay as well as a good ground
This would
Rule out the ignition switch pcm fuse and relay as the issues

You can check for power at the pcm power feed wires from
Relay as well but we can get into that after these first checks are done

How did you “check” the relays? If the eec (pcm) relay does not “Click” when you turn the key then you have either a bad ignition switch or wiring to or from or a bad fuse or the pcm relay itself is bad

I checked the relays using alligator clips from a 12v battery and then took a multi meter to check for continuity. All relays clicked and were good to go.

Fresh battery and is reading 12.6 volts. I’ll have to wait for the wife to get home but I did have her turn the ignition on and I stood by the relays and did hear a click.

So maybe a bad ignition switch? How would you suggest testing for that?

 

[Josh P]

When you turn the ignition to the run position, do other accessories such as the radio turn on?

 

[JakeRenshaw89]

When you turn the ignition to the run position, do other accessories such as the radio turn on?

Yes sir, seems like all accessories work just fine.

 

[Josh P]

Yes sir, seems like all accessories work just fine.

That would indicate the ignition is functional. Seems like a power or ground issue to the ecm. Lottery odds the ecm decided to go tango uniform on you while driving, but not impossible.

 

[JakeRenshaw89]

That would indicate the ignition is functional. Seems like a power or ground issue to the ecm. Lottery odds the ecm decided to go tango uniform on you while driving, but not impossible.

That’s where my head is at that the PCM has taken a sh*t! Just odd to have it fail while driving, thanks again for your inputs. Standing by to see if 410Fortune agrees! (While I look at an 80 Series Land Cruiser!)