Either the wiring is not stock or the computer you are putting in is also bad.

 

Thanks for the reminder. I'll look into it right now.

 

To be clear, when using a jumper from #6 to #2 in the test connector, I can hear the external pump running.

The ground to the battery is fine.

 

Where can I buy a new harness made for my 1985 F150 5.0 EFI with all connectors, etc.?

 

So without the jumper how does it act?

 

If you have the cash, an original 85' ECA may be another avenue......

 

Hi Vince -

So I have it to where it works the same as before. There's a 1 - 2 second time where the pump runs, it stops running and the engine starts - smooth running. However, there is still no current to the internal fuel pump. I just can't figure it out.

I suspect when it rains again, I'll have the same problem where the external pump runs forever until something happens that causes it to stop.

Plus, I still can't pull any codes, I think my wiring must be screwed up and I'm tired of trying to figure out where there's a break. Aside from that, I'm not schooled in how to really see if there's a break. I know I use both connectors at each end to check continuity but I don't think I'm doing it right.

I ordered a new harness from Ron Francis harnesses. It's actually a Cobra harness that will fit my Ford (so they say) and will be configured to work with the MAP system instead of the MAF system. Hopefully, the new harness with fresh connectors and new wiring will make the difference. What a job that will be!!!

How's the knee?

 

Use controlled rain ... Get the garden hose out!

As in only wet a little at a time.

-Enjoy
fh : )_~

 

Would ye know any Priest lad? Making a car wash might not be a bad idea………

Knee gets better every day!!

Can you get to the wires connected to the internal pump/sending unit?
“no current to the internal fuel pump” Do you mean “current” or Voltage? (current flows when relay is energized)

To troubleshoot yourself you will need to learn how to use a test lamp, but you can’t check everything that way. You need to learn to measure DC Voltage, DC Current & Resistance (Ohm’s). Without this knowledge, it will be very difficult for you to troubleshoot electrical & electronic issues with your truck.

No good ever comes to a non-stock cable replacement……. Do you really think you have a wire harness issue? “What a job that will be!!!” Or Mistake….

Are you positive you have the right version ECA/ECM in there??

 

Hi Vincent -

Glad to hear your knee is doing well!

I can get to the internal pump easily. I have a wooden bed and a panel that easily is removed to get to the tank. The pink wire seems to have no current coming through it. I used the positive connector to my voltmeter connected to the pink wire and ground the black wire to the frame. I had the voltmeter set to 200 Volts. I turned the ignition to the on position, but not the run position. It read 00.0. I could pull the pump to check the wires (it's a new pump) but if there's no voltage coming into the pump it seems pointless.

And, I still get 000 when I try to pull codes. That tells me there's something amiss. The black ground running from the battery negative cable to the ECM is grounded fine as far as I can tell. I didn't check that with the voltmeter, but I did cut the wire and sliced it to ensure it has no breaks in it.

The new harness is being crafted by Ron Francis Wiring. They seem to be reputable, but I, like you have concerns. The harness they can make for me is actually a Cobra harness for MAF. I have a MAP system so they'll have to change that. They'll also have to change the firing order. However, they stand by their product and tell me that they'll will ensure it's a perfect fit. Still, I have concerns and may cancel the order.

The ECM is the right ECM according to the calibration list Gary sent. And it is the same number as the one I replaced. It seems there wasn't an issue with the ECM to begin with, but I'll hold onto both at this point.

When I rebuilt the engine I took the harness off and put it back. I have everything where it's supposed to be. I know this because I had everything clearly marked and had corresponding connectors marked as well. Still, I can't help but think something isn't quite right due to the internal pump not kicking on. In fact, I can disconnect the connector to the internal fuel pump and the engine runs just fine. The external pump is doing all of the work.

IF they craft me a new harness with the right connectors and so forth, it'll should work fine.

Right now, I'm frustrated beyond belief. I'm not a mechanic by trade and not an electrician. When the thing starts it's as smooth as silk, has plenty of power, and pulls me back into the seat when I punch it. It's acceleration is remarkable. And if I wanted to, I could do donuts just like the boys on Fast and Loud. I confess I do punch it on the highway for kicks and do occasionally spin the tires and leave marks on the road. It runs so good, but I want it to be perfect. I'd like to leave it to my son when that time comes and I want to get it right so he doesn't have to mess with it.

 

Have you tried pulling codes with a test light? Maybe you already tried that and I just don't remember.

 

Yes. I get nothing. No blinks whatsoever. Somethings really amiss.

 

If you don't have power at the pump with the key in START, the next logical place to investigate would be at the fuel pump relay... is the relay being actuated, and is there power in the supply wire (the yellow wire, comes from the intertia switch) to even supply to the pump, should the relay actually do its job?

This is all easy to check for by using a voltmeter like you're doing at the pump, put the mater on the leads and have someone turn the key to START for you.

 

I will try that tomorrow. It's a good suggestion. The relay is new, but I'll test the wires.

Thanks!!

 

It is the *computer* that tells the relay to apply power to the pump... and you can't pull codes from your computer, that strongly suggests a problem at the computer.

Haven't we been down this path already? I've been following this thread for a long time now, and recent discussion is, you got a new computer that still behaves the same way? That would point you to wiring, or the wrong computer, or a defective computer, or....

Probably I left this thread alone and didn't participate so much because you've already got some really good guys helping you and I had nothing to add.

But, yeah, go check at the relay, anyway, but don't be surprised if you find the computer is NOT telling the relay to send power to the pump.