8404DOC

Need some help,
1990 F-150 351
Replaced the connector in the steering column from the ignition switch to the key tumbler, combo steering lock pot metal piece). Everything went back together fine and the key turns and the starter kicks over but I don't hear the fuel pump kicking on and it won't start. I replaced the ignition switch on the column and am wondering if I got the wrong switch or if there are different switches for fuel injection?
I was able to do the old screw driver trick at the starter solenoid prior to tearing it apart to get it into the garage.

OtherWeckta

If you could get it started using a screwdriver across the solenoids but not with just the key in the ignition is doesn't sound like it's a fuel pump issue... your pump would have had to be on in whatever position the key was in when you crossed the solenoid terminals in order for it to fire up

8404DOC

With the key in the on position I could hear the fuel pump run and it started with the screwdriver but that was prior to replacing the ignition switch. Now with the new switch it won't start at all, with the key or across the solenoid. I can remove the fuel pump relay and install a jumper to get the fuel pump to run but it still won't start. The old switch was thrown away so I can't compare old to new.

ymeski56

About 4 months ago, someone had a similar problem. The F/P relay actuated, but no power to the pump. Currently, another member, the PCM relay actuated, but no power to the PCM. In both cases, the wire connectors going into the bases for the relay's had corroded & lost contact w/ the relays when they were in place.

Is the small solenoid actuator wire from the ignition to the solenoid connected?

1987 F-150 XLT 4x4

There are two relays under the hood on the driver’s side fender well.

I copied & paste what ymeski56 said a while back:

Relay #1 is the PCM Relay (Brown)
It powers the EEC & allows the Fuel pump relay to energize.
If it isn't working, neither will the ECC nor allow the Fuel pump relay to energize itself.

Relay #2 is the Fuel Pump Relay (Green) located next to the ECC relay.
They appear the same, but aren’t and will not interchange.

---------------------------------------------------------------------

I copied & pasted what Nitehawkjr wrote a while back. (Quote)

The fuel pumps are controlled by the PCM when the engine is running.
This is how my manual explains it.

When the ignition switch is on, it turns on the EEC power relay on.
The EEC power relay supplies power to the power train control module (PCM)
and the control side of the fuel pump relay.

Power for the fuel pump(s) is supplied through a fuse link or high current fuse
attached to the starter solenoid (battery side).

From the fuse link or high current fuse power flows through the fuel pump relay,
inertia switch, selector switch to the fuel pump(s).

The fuel pump relay is controlled by the PCM.

When the ignition switch is turned on the fuel pump(s) will operate.

If the ignition switch is not turned to the start position
the PCM will shut the fuel pump(s) off after 1 second.

The PCM will operate the pump(s) when the ignition switch is turned to the start position
to provide fuel while cranking.

After the engine starts, the PCM will continue to operate the pump(s) until the engine stops,
drops below 120 RPM or the Inertia is tripped.

Check out the wiring coming from the PCM to the relay.

Check out the grounds also.

The pump pressure you should have is 35-45 psi.
Also it could be that the PCM is not sending a signal to the injectors to pulse. (Unquote)
---------------------------------------------------------------------

Attach a Fuel Pressure Gauge to the Schrader Valve
on the fuel rail to ensure you have fuel pressure there.

I don't think the problem is in the ignition switch or in the steering column.

Check out what ymeski56 said, that could be it...

Look at the pictures to see if they help any.

Let us know what the problem was!

ymeski56

Well done sir! You do us 87' F-150 owner's proud represent'in.

8404DOC

Alright I figured it out.
Replaced the fuel pump relay and the EEC relay but it still didn't start so I broke down and bought a Chiltons manual with a fairly good wiring diagram and started tracing with my test light. I started with the red/light green stripe wire coming out of the ignition switch. It had good power at the switch with the key in the on position so I moved to the EEC relay, I had good power at the wire going into the relay connector so I went to pull the relay off and the fuel pump relay kicked on!
I was able to make the relay go on and off by pulling and pushing the relay in and out so I knew I had a bad connection in the connector. I turned the key off, removed the relay, pryed off the red cover on the end of the connector. With a small flat screwdriver I released the terminal and slid the red/light green stripe wire out of the terminal. It had a small amount of corrosion inside so I cleaned it and replaced it in its original position, replaced the red cover and replaced the relay.
Problem fixed! I guess it was a coincidence it went bad while I was repairing the ignition switch but isn't that how it always goes. If anybody would like pictures let me know and I will try to take a few to describe the fix otherwise my son is taking the truck back to college on Sunday. Thanks everybody!

ymeski56

Corrosion at the relay base! Sounds like Deja vu, all over again. Thank for getting back to us w/ the cause & cure. Otherwise our suggestions remain educated guesses at best. No fun for us if we don't nail one once in a while.