Oh yeah! I was using that just last night for the tester. I wasn't aware that it was called the EEC connector!



Ok, just so I don't blow fuses or do something stupid; I use a jumper wire to ground this (circled in red) pin to a chassis ground (with the key ON) and the fuel pumps (if working) should turn on?

Assuming they DON'T turn on; how do I tell if it's the PCM that's bad versus bad pumps? I assume that if the PCM is GOOD, the pumps will be getting 12v with this jumper in place and if the PCM is BAD they will not be getting 12v with this jumper in place?

Thanks again!

 

Well, I didn't do the jump to check the fuel pumps this evening because my battery has died once again (to be fair, I am using a very old battery that was already replaced from a friend's vehicle...just as a tester) so it's on the charger once more.

That said, I did get the new coil in, but alas, I won't be able to check for spark until she's charged up.

Additionally, I removed the PCM/ECM to check look for a burned board, but after looking at it, I don't see anything that really looks burned or even somewhat fried. Anyone else see anything that may look amiss? Is there a way to test this computer? I kind of doubt Autozone does it...

Here are the pics!

 

Jumping that bottom right pin on the EEC connector bypasses the computer. It directly turns the fuel pump relay on.

 

Fantastic. Thanks for the confirmation. As soon as I get that battery charged I'm going to check it out

 

Ok so tonight I was able to go out and perform this jumper test. The pumps didn't kick on though; all I could hear/feel was the relay clicking...what the heck does this tell me?

Thanks!

-Matt

 

It tells you either

A. The relay is bad
B. The fuel pumps are bad
C. The inertia switch is tripped/bad
D. The wiring between the fuel pump relay and fuel pumps is bad.

 

I know you are getting excellent advise here, as I have. You seem skilled enough and willing enough to get things done. So my advise is based on me and me alone. Buy the Haynes and Chilton Manuals for our trucks. They helped me understand from a different perspective so I could get forum help and by the book help. The pictures help also for identification purposes. Extra book help can help you converse with the experienced here for better faster help than someone like me. I think you will succeed if you don't get them and I know you will do it better faster and wiser with the manuals. I even bought the $20.00 CD Ford Manual and it's OK but slow to navigate and written in a totally different perspective than above. Good Luck. I really like your truck. Sandy

 

LH, thanks so much.

A. I'll buy a new relay just in case to rule this out
B. Thinking this could be possible - will be able to check this weekend with my buddy's assistance.
C. I know it's not tripped, but that certainly doesn't mean it's not bad...any way to check that switch other than replacing it?
D. Damn I hope that's not it...

Thanks Sandy! I actually just got my Haynes manual tonight. I know how invaluable they can be and I use them for my motorcycles and other vehicles as well. That said, I kind of wish they'd have broken this one down a bit better - it seems like it covers so many years that parsing out which section is applicable and which isn't for my model year is going to be rather challenging...that said, I *did* just get it tonight.

Thanks for the compliment! I want to spend some time cleaning her up, but not until I get her running again, which is proving more difficult than any vehicle I've yet tried to "resurrect"...

 

You're welcome. I noticed you posted another thread. The folks helping you don't like that and for good reasons. I thought I was doing the right thing by starting a new thread and found out different. <<<Just a heads up. Your help won't leave you and more will join in as you go along.

 

Thanks Sandy!

I waffled on the started the other thread but was hoping since it was more of a "PCM"-specific test question that I might be able to help future folks who were more certain that they had a PCM issue and were searching with that keyword. I certainly hope I won't be stepping on too many toes with threading faux pas

 

Before you rule out the fuel pump(s) are bad try switching the fuel tank selector to the other tank. Possible the fuel pump you tried jumping is inoperable and the other pump could work just fine.

When I went through this with the '89 I just bought I had an intermittent in tank pump issue. But the other tank worked just fine. Scratched my head for days trying to figure it out. Would run fine for 5 minutes to 2 hours then shut off. Mine has a frame mounted pump which yours does not.

Let us know what you find out. Also, are you trying it with the key on and grounding that pin?

 

Nova,

Total headslap there, but you're right, I didn't try switching the tank over...in fact, I'm going to go try that right now...too easy not to!

It is Key On, Engine Off when I ground it. Be right back, gonna try it!

 

Welp,

My test battery (which is old as sin) is on its last legs...that said I was able to flip the switch and try the other tank. Still just the clicking. I'm going to suck it up tomorrow and buy a new battery. I need to rule out that stupid battery as part of the problem as well.

 

I was really hoping for better results but it is what it is. When you are grounding the pin does the fuel pump relay click?

 

Did you ever check your ICM Ignition Control Module? If not, I would check it now and it is easy to do. How long did your truck sit before you bought it? Standard or Auto?