02 expedition will not start

[theoldwizard]

Originally Posted by Dk's MS6

Well that's what I get for assuming. I read a note regarding the fuel pump relay stating the primary circuit was controlled by the PCM. It then stated the secondary circuit was linked directly to battery voltage from the ignition.

On a typical return fuel car this is true.

Do you think there should still be voltage at the fuel pump if there was an issue with the electronic regulator?

If the module is broke, you would probably get zero volts at the pump immediately after KOEO.

I checked the camshaft position sensor today. I was unable to get a voltage reading from the PCM on the wiring harness KOEO.

Both the crank and camshaft sensors are "voltage sources". That is they generate their own voltage (AC) when the engine is turning (a very small voltage when the engine is cranking), so you won't see anything on those pins if the engine is not spinning.

Someone else suggested simply disconnecting and reconnecting the crankshaft position sensor. This action actually "cleans" the contact (pins). A small amount of corrosion can prevent the signal from getting to the PCM. If the PCM gets no CPS it will not turn on the fuel pump, fire the injectors or the plugs.

[BroncoJoe19]

I have tested the fuel pressure at the fuel rail (there is none), the fuel pump fuse and relay (both work), and checked for voltage at the last connector to the fuel pump near the left rear tire (10.5v or so KOEO). I can not hear the fuel pump turn on with the KOEO at all
That voltage is a little low. Shouldn't it be the same as your battery voltage?
ALso did you check the ground?
If you are getting voltage to the pump, AND have a good ground it should turn on.
You may want to try running power and ground directly from the battery to test the pump to see if it will turn on.

If you need a wiring diagram, Autozone usually has them online in their troubleshooting section.

[BroncoJoe19]

The ground for the pump on a '99 is at the left front (driver's side) radiator support.

[theoldwizard]

Originally Posted by BroncoJoe19

I have tested the fuel pressure at the fuel rail (there is none), the fuel pump fuse and relay (both work), and checked for voltage at the last connector to the fuel pump near the left rear tire (10.5v or so KOEO). I can not hear the fuel pump turn on with the KOEO at all
That voltage is a little low. Shouldn't it be the same as your battery voltage?

The returnless fuel control module could drop the voltage.

You may want to try running power and ground directly from the battery to test the pump to see if it will turn on.

Good idea !

[Dk's MS6]

Originally Posted by theoldwizard

Both the crank and camshaft sensors are "voltage sources". That is they generate their own voltage (AC) when the engine is turning (a very small voltage when the engine is cranking), so you won't see anything on those pins if the engine is not spinning.

Someone else suggested simply disconnecting and reconnecting the crankshaft position sensor. This action actually "cleans" the contact (pins). A small amount of corrosion can prevent the signal from getting to the PCM. If the PCM gets no CPS it will not turn on the fuel pump, fire the injectors or the plugs.

That makes sense, I wasn't sure why a magnetic sensor with an AC output would have a DC input. I disconnected the sensor and plugged it back in, no luck. I used a little dielectric grease on the contacts when I reconnected it. I have tried to be religious about that with each one.

BroncoJoe19:
You know, my poor old dad was the one under the truck checking the voltage, it may have been higher, I didn't see the reading and just can't recall what it was.

I will run the power and ground lines this afternoon, I work 12 hour shifts on nights and should get a little sleep at some point here.

Thanks for the info about the autozone web site, they didn't have my year (02 expedition Eddie 2wd w/auto suspension). I have a wiring diagram here so I should be in pretty good shape.

[Dk's MS6]

Well I got it all buttoned up today. I checked the ground as suggested above. Looked to be OK, so I just dug right in. I used a motorcycle jack to support the fuel tank while I unbolted the straps. Came right down without a hitch. I bench tested the fuel pump after I got it out, Nada. It didn't do a darn thing. I wasn't able to use the autozone web site for a wiring diagram, but I was able to use it to source the new pump.

Total cost of the project:
$135.29 fuel pump and a new fuel strainer.
$43.09 Fuel pressure gauge.
$11.29 Fuel filter.
$7.37 Battery cleaning kit/anti corrosion goop.
$50.86 New Motorcraft spark plugs.
$8.71 dielectric grease and anti seize compound.
$57.87 K&N air filter.
Total cost:$314.48

I would suggest anyone having similar problems:

1) Check the sensors and the IAC before dropping the tank out of this thing. Take your time and double check each sensor, be sure to use dielectric grease on the fittings, Ford did not use a drop of it on this truck.

2) If you can, invest in a fuel pressure gauge. I could have eliminated $124.81 in air filter, spark plugs, and what not if I had the gauge in the first place.

3) Ask questions, there is a ton of knowledge on this forum, Thank you OldWizard and BroncoJoe19.

[theoldwizard]

Your Welcome ! Smart move to do the fuel filter also !!

Fuel pumps do fail, but I'll bet most that are replaced have a lot of life in them (same is true about batteries).

In general, fuel pumps announce their impending doom by MAKING A LOT OF NOISE or causing some kind of issue with the fuel pump relay.

[BroncoJoe19]

You're welcome, and thanks for posting back. It is nice to see an issue get resolved, and what it took to resolve it.
Be well,

[Dk's MS6]

BTW, I checked to see what my local dealer would have charged for the same diagnosis/work performed: $1682.92. Merry X-mas to me

[dirtroadplath]

so it was the fuel pressure regulator?