First EFI start attempt failure! Code 87??

[73bronco]

Well I got my fuel pumps today and installed them. I tried to prime the system before first start and it would not run the pumps. So I tried to crank it. Still didnt run the pumps. Now I am getting code 87 "Fuel pump primary circuit failure. When the FP relay was activated by the EEC, voltage was not detected on the control circuit". I jumped the wire and ran the pumps to fill the system. Then tried to start it...still no start. Any help??? I really want to get this thing going tonight!!

 

[ransil]

Did you connect the FPM ( Fuel pump monitor) pin on the computer to someplace on the fuel power circuit??
Does the pump cycle when you turn the key??

when you turn the key to start the computer grounds the FP replay which activated the Fuel pump, the FPM wire should be on the output of the relay or the inertia switch.

 

[73bronco]

I am a complete dumba$$!! I figured it out and now it is running!! I need a wire that is hot in run and start now......Which wire is it at the ign switch?

 

[Viperwolf1]

I am a complete dumba$$!! I figured it out and now it is running!! I need a wire that is hot in run and start now......Which wire is it at the ign switch?

No switch terminal is hot in start and run.

 

[lars]

No switch terminal is hot in start and run.

I didn't think so either, and I drove my Bronco with EFI for a few years on that assumption (it ran & continues to run fine). Then a local friend said that the coil & voltage regulator output pin on his ignition switch was in fact hot in crank & run. So I checked mine. Sure enough. It was/is. Original 1970 ignition switch. Factory wiring diagram for that year implies otherwise. Go figure.

 

[Viperwolf1]

I didn't think so either, and I drove my Bronco with EFI for a few years on that assumption (it ran & continues to run fine). Then a local friend said that the coil & voltage regulator output pin on his ignition switch was in fact hot in crank & run. So I checked mine. Sure enough. It was/is. Original 1970 ignition switch. Factory wiring diagram for that year implies otherwise. Go figure.

That's because the resistor bypass wire (brown) was attached to the "I" terminal of the starter solenoid and the RUN terminal of the ignition switch (through the resistor and coil+ wire). The switch itself doesn't have a physical connection.

 

[ransil]

Red Blue wire is Start
Red Green wire is run

 

[lars]

That's because the resistor bypass wire (brown) was attached to the "I" terminal of the starter solenoid and the RUN terminal of the ignition switch (through the resistor and coil+ wire). The switch itself doesn't have a physical connection.

No, it wasn't. When I checked the circuit I pulled the connector off the back and measured pin to pin on the switch. And in any case none of the original wiring exists on my Bronco. Centech harness, custom (built myself) EFI harness, original coil wiring architecture is long gone.

 

[Viperwolf1]

If that's true it would had to have been on the red-green and green-red wire terminal.

 

[lars]

If that's true it would had to have been on the red-green and green-red wire terminal.

Measured across the battery terminal (yellow wire in stock harness, if memory serves) and the voltage regulator terminal (green w/ red stripe in stock harness), using my trusty Fluke DVOM.

I use the starter motor terminal (red/blue in stock harness) for crank only.

As I wrote, I was surprised at the result, and checked it several times, since I was certain that it would not be so.

 

[Viperwolf1]

I have an old ignition switch somewhere. I'll have to dig it out an test it.

 

[lars]

I have an old ignition switch somewhere. I'll have to dig it out an test it.

Please do, report back. I suppose it could be like so many other things, where Ford had multiple suppliers and the parts weren't always identical, despite presumably being manufactured to the same spec. I've encountered that in other industries during the course of my career.

 

[Viperwolf1]

Please do, report back. I suppose it could be like so many other things, where Ford had multiple suppliers and the parts weren't always identical, despite presumably being manufactured to the same spec. I've encountered that in other industries during the course of my career.

You are right. Ignition terminal is hot in START and RUN (red-green and green-red). This was the old Motorcraft switch from my '74. Could have been original. Marked RBM on the side.