My 1991 F350 w/ 351W (5.8L), was idling fine in the driveway when it just killed. I do not hear the fuel pump coming on now and I also have no spark.

On the spark issue, I have pulled the rotor cap to ensure there is normal distributor rotation, and there is power to the primary side of the coil.

On the fuel side, I have checked the inertial switch (it is fine) tried grounding the fuel pump circuit through the "test" port on the EEC computer plug...still no fuel pump.

Does any one have any ideas on what is a common thread between losing spark and losing the fuel pump? Thank you.

 

Did you turn the key "on" when you did the pump test thing?

Anyway sounds like total loss of power to system, check the fuse links at the starter relay. One you should pay particular attention to is brown, power to ignition.

 

Yes, I had the key turned to the "Run" position. I will look at the fusible link and see what is there. Thanks.

 

module on the dizzy ?

 

Well, I started out at the wrong end of the problem with my trouble shooting but thanks to an old post by SUBFORD I got back on track. There was a procedure in my manual for testing circuits on the EEC-IV processor, but that required removing the wiring harness from the computer (kind of a pain). When I got the processor out, I found I didn't know how the 60 pins were numbered. In my search for that info, I found SUBFORDS post on trouble shooting the EEC-IV system.

As I had no voltage at the wiring harness side of pins 37 and 57 (with key turned ON), it led me to the EEC relay. I checked for voltage coming into the relay (one hot all the time and one hot with key turned on) and found it to be correct. Therefore, EEC relay was not allowing power from the battery to the processor. $14.50 for a new relay and she started right up.

I hope my explanation is clear. So, if you have no spark and no fuel pump coming on, you might want to check the EEC relay first. For $14, I would try that BEFORE taking out the computer.