1992 f150 4.9 was running fine and just died. . I have no spark and no fuel pressure. . No power to Inersia switch. . Jumped #2 and #6 on eec test switch and still no power to inersia switch thus no power to fuel pump.. no power to eec test strip at all tested with test light.. Thinking bad ECM.. would appreciate any ideas or input. . Thanks in advance..

 

When you jump pin #2 to pin #6 you are still running the ground through the ECM (PCM). Try grounding pin #6 with the key on and see if you have power then.
If still no power it is not the ECM (PCM).

Next would be to check for power with a loading test light at a red wire at any injector and the + (POS) side of the Ignition Coil with the key on.

If no power at any injector and the + (POS) side of the Ignition Coil with the key on then check the Ignition Switch and the yellow wires at the Starter Relay battery side.

If you have power at the injector and at the + (POS) side of the Ignition Coil with the key on does the Power relay click each time you turn on the key?
If not swap the horn relay with the power relay and if still no click check the body ground on the passenger fender.

 

Pulled the ecm and it is fried.. Just wondering now what caused it.. Don't want to spend the money installing a replacement only for it to fry right off the bat..

 

Something has fried the ecm.. watched a u tube video of someone with a similar problem and they got their advice from this forum.. I jumped pin #2 with pin #6 on the eec test strip with the key on just as they showed on the video but still no power at inersia switch. . Hope I didn't fry the ecm by jumping #2 with #6 on the eec test strip.. ?

 

No it would not hurt the computer by jumping pin #2 to pin #6.
Pin #2 is goes to ground through the computer to the body ground over on the passenger fender.
Pin #6 goes to the coil of the fuel pressure relay to pick that relay and also goes to pin #22 of the computer so the computer can ground this same wire and coil.
The other side of the fuel pump coil gets its power from a red wire coming from the power relay NO contact. The power relays NO contact closes with the Ignition key in the run or start position. The power relay Common contact gets its power from the a fuse link over at the starter relay on the passenger fender battery side.



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Thank You very much for your input.. Much appreciated. . I removed the ECM and opened it up and it it obviously has a burnt diode or capacitor of some sort.. Guess I'm gonna try and find a good used one and see what happens.. Don't want to take a chance on a reman in case it burns up again.. All my grounds r tight.. and can't find any shorts any where that may have caused the problem. .

 

Old dried up capacitors typically cause PCM failures including burned components.

 

Thanks everyone for all the input.. Gonna take a chance and put a remanufactured EEC module and see what happens.. Been a good truck and very dependable motor up until now.. Guessing the 284 thousand original miles may have something to do with the eec module going bad. That and all the heat and humidity that we have been having here in the Bootheel of Missouri. . Will post an update when and if I eventually get it back running.. Thanks again everyone..

 

Installed a remanufactured EEC today and it started right up.. Thanks again everyone for all the input and advice it was very helpful and greatly appreciated. ..

 

Driving down the road and engine died so switched tanks and continued on restarted in neutral rather than pulling to the shoulder of the road. Started right up. Continued just fine for a few miles and died again. Previously was having trouble engine would start fine but die shortly after. Can this be failed ecm?

 

Please start your own thread instead of tagging onto an old one.