2.9 fuel pump problem

[Beef52751]

My 86 ranger 2.9 died the other day with no fuel pressure. I did some digging around but can't seem to pin it down. It will run if I ground the fuel pump port from the OBD connector but the ground seems good right above the computer? Where do I go next? I've searched a ton and almost every thread says ground the port and see if it runs.....but no one elaborates on what to do if it does run. Haha, thanks for any help you can offer.

 

[RonD]

Here is the pin out for EEC-IV (pre-'95 Rangers): http://www.auto-diagnostics.info/ford_eec_iv

Pin22 is the Ground for the fuel pump relay, it's wire is spliced in to the OBDI connector, the one you are grounding to get fuel pump working.

The EEC has several Ground pins, they are not all connected internally, so one loose ground could cause this, or it could be bad EEC circuit.

If you remove the EEC connector and test pin 22 on the connector that wire should have 12volts when key is on, if not then the splice is bad, ODBI connector wire is good but splice to EEC pin 22 is bad.

You can just leave the OBDI connector slot grounded, it won't hurt anything to drive the truck that way, the pump will shut off and come on with the key, and the inertia switch will still cut off fuel pump power if a roll over or accident should occur.

You could even install a Ground switch in the cab as an anti-theft device
Wired to the OBDI slot

 

[Beef52751]

Well I grounded the obd fuel pump port and the truck ran fine in th e garage so I thought I had it good to go. Buttoned up some other stuff and took it for a drive, made it about 1 mile before it died... fuel pumps still running but not starting. I guess there is another issue somewhere. Must not have spark now...

 

[Beef52751]

I got it running again. Swapped computers and it fired right up. I opened up the old one and a transistor had melted off.