First post...I've had a mess of problems with my 88 Ranger FI 2.3. The latest was that it would run for about 9 minutes and then stall. Sometimes after it would stall the EEC power relay would start clicking. A friend helped me isolate the problem to pin 22 out of the EEC which goes to the fuel pump relay. When it goes high, no power to the pumps. But why? Unfortutately, we couldn't get any codes. Since I had already replaced the EEC it was suggested the problem might be with the ignition module. So I replaced that last week and nothing changed.

Since the EEC had a one year warranty I thought I'd try that again. (I've heard of people getting bad rebuilt computers.) Popped in the new computer, this time heard the fuel pump run continuously when turning the key to on. (It didn't run for a second and shut off like it's suppose to.) I tried starting it...ran for about a second and then quit. Now I'm back to square one, except that before it would go for 9 minutes. Any ideas?

 

...Welcome to Ford Truck Enthusiasts!
Stick around someone will be by shortly to answer your question.
We are happy you have chosen the best source for Fords!

Enjoy FTE....and
JOIN CLUB FTE -SUPPORT THE FORUMS!
…..See you on the boards.

 

Bueller? Bueller?

 

Bueller went for lunch.

I *think* that the ECM supplies Ground to the fuel pump relay. As in, the relay gets its 12v from the battery and then the ECM grounds the other side of the relay coil and the relay engages. This is an electronic design trick to limit the juice to be supplied by the ECM, instead, it just has to pass the juice back to the frame (ground).
I betchur ECM is not supplying the ground on pin 22. Seems the ECM may be defective.
It is a little late, but you should have checked the part number, build code, brain fade on the term but it is the emission "batch" level, as you may have gotten the wrong one from your supplier. I would also check the fuel relay amp draw by taking the ECM out of the circuit and supplying 12v and ground thru an ammeter. It shouldn't take many amps. And, it shouldn't get hot or smoke.
THe time thing to me indicates something is getting hot, (or was) and an electrical connection, perhaps a winding in a relay, was opening up and de-energizing your fool pump.
tom

 

Tom, thanks for the reply. Will have to try this out. I ordered the computer from Advance Auto. I'm thinking they ordered it based on make/model, engine size, EFI, and it being an automatic. How and where would you suggest getting the right computer if in fact it was the wrong one? Also, how would I keep a part, say a relay, from getting too hot? I'm think I'm getting in over my head. Thanks again for your help!

Wishing it was mechanical,
kacey

 

The word I was looking for is 'calibration'. As the model year progresses, the manufacturers may come up with some new whizbang combination of emission settings that will save the world and make sliced bread look old fashioned. This combo is called a calibration, thought that is not what the word originally means. If your engine was set for a specific calibration, then a one-size-fits-all ECM may not work correctly.
If you could re-install the old one, you might find that there is nothing wrong with it. Ford has a very good record for their ECMs, with few failures.
Any of the relays- fuel pump, ECM, headlight, trailer light, fan or whatever do not run hot when energized. They may be warm, such that you can hold them in your hand with no problem at all, but not hot.
I would watch the pin on the ECM that grounds the fuel pump relay. It should ground for about 3 seconds, then shut off. Your relay apparently is being grounded for a second, and it may be that it is drawing too much current. Check it as noted to see the draw of the relay itself, not what it is powering, though it would be a good thing to know how much the fuel pump(s) draw. They draw more amps as they age, apparently, and your pump may just be on the fringe of acceptable draw. That would not explain the relay functioning the way it does, though. If it had been me, I would have replaced the relay before the ECM... a lot less dough.
tom

 

you could always runa 12volt,, switch direct from the battery to the fuel pump ,,bypass the relay,i have done this no problem,just remember to shut off the pump,i use a 110v house switch they last forever,makes a good anti theft gizmo also