97 F-150 stall and won't start for hours after
Thread Starter
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Junior Member
Joined: Aug 2020
Posts: 5
Likes: 1
97 F-150 stall and won't start for hours after
I have a 97 F150 4.6 4x4 Itr great for 20 minutes then stalls out and won't restart for 8-12 hours. . Get no fuel and no spark. The PCM get very hot to the touch. I have a spareTspare PCM and switching themcthem changes nothing still 8-12 hours. engine light come on with ignition switch so PCM is getting power The OBD2 port has power but reads data link error and won't read codes. Once it restarts it reads fine and shows no codes.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
With a catastrophic outside initiated failure like you describe, the PCM cannot set any kind of code if it cannot do basic operation.
I say outside initiated because you have tried a second PCM with the same result.
My guess and only a guess I rarely offer is a harness or sensor issue.
The no spark no fuel is telling us the PCM cannot work because it controls both..
Begin at the Crank Sensor to look for an issue because it has to send pulses to the PCM for everything else to work.
Only time this Sensor is not used is at initial turn on when the PCM gets power and runs the fuel pump for about 4 seconds. You might check this and see if it runs.
Best I can offer at this point.
Good luck.
I say outside initiated because you have tried a second PCM with the same result.
My guess and only a guess I rarely offer is a harness or sensor issue.
The no spark no fuel is telling us the PCM cannot work because it controls both..
Begin at the Crank Sensor to look for an issue because it has to send pulses to the PCM for everything else to work.
Only time this Sensor is not used is at initial turn on when the PCM gets power and runs the fuel pump for about 4 seconds. You might check this and see if it runs.
Best I can offer at this point.
Good luck.
Last edited by Bluegrass; Aug 10, 2020 at 09:07 PM.
Thread Starter
|
Junior Member
Joined: Aug 2020
Posts: 5
Likes: 1
With a catastrophic outside initiated failure like you describe, the PCM cannot set any kind of code if it cannot do basic operation.
I say outside initiated because you have tried a second PCM with the same result.
My guess and only a guess I rarely offer is a harness or sensor issue.
The no spark no fuel is telling us the PCM cannot work because it controls both..
Begin at the Crank Sensor to look for an issue because it has to send pulses to the PCM for everything else to work.
Only time this Sensor is not used is at initial turn on when the PCM gets power and runs the fuel pump for about 4 seconds. You might check this and see if it runs.
Best I can offer at this point.
Good luck.
I say outside initiated because you have tried a second PCM with the same result.
My guess and only a guess I rarely offer is a harness or sensor issue.
The no spark no fuel is telling us the PCM cannot work because it controls both..
Begin at the Crank Sensor to look for an issue because it has to send pulses to the PCM for everything else to work.
Only time this Sensor is not used is at initial turn on when the PCM gets power and runs the fuel pump for about 4 seconds. You might check this and see if it runs.
Best I can offer at this point.
Good luck.
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
The issue calls for an in depth look at all areas.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
Thread Starter
|
Junior Member
Joined: Aug 2020
Posts: 5
Likes: 1
The issue calls for an in depth look at all areas.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
Thread Starter
|
Junior Member
Joined: Aug 2020
Posts: 5
Likes: 1
The issue calls for an in depth look at all areas.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
Start with fuse and relay seating.
Check the grounds behind the kick panel.
Are you sure there is no spark when cranking?
Have you tested for fuel pressure at cranking?
If you don't look under every stone, it will not be solved.
Good luck.
