88yotadad

I was testing the wiring at the pump but have no reference to go by. There is 3 wires going into the pump. Wires are white/balck , yellow/blue and yellow/red.
With the ingition in the on position I have no power at any wires. When cranking I have between 3 and 4 volts between white/black and yellow/red.
The Hanyes manual I have does not have any info on testing these wires.
Any input would be great thanks Roger

eric-the-red

Looking at my manual the yellow/blue and yellow/red wires are for the sending unit for the fuel guage. The pump is powered by a solid blue wire, and the white/black is the ground. The sending unit uses a 5 volt circuit, from the instrument panel so that could explain the 3-4 volts you are getting.

Have a read through this, it's for an older model but may help. Even if it doesn't Roger Brown's site has lots of useful and interesting info.
http://www.4crawler.com/4x4/CheapTri...shtml#FuelPump

MSR

check the circuit opening relay in the right kick panel above the ecm make sure it is putting out batt voltage at the blue wire when cranking or when you hold open the airflow meter door with key on.

88yotadad

Thanks, I'll try again in the morning.

thook

Here's a fun little test.
http://personal.utulsa.edu/~nathan-b...87fuelpump.pdf
Bypasses the COR switch and VAM. If it the pumps runs at this point, you know it's either of the two.

88yotadad

Thanks for the info and links. The links where very helpful.

I found a broken wire. It is the power wire going into the tank. Not sure if it was broken or that I broke it trying to test. I ordered a new fuel pump bracket.(OUCH) I completed the circuit with my mullti-meter and The pump did not work and showed 0.08 of a volt passing thru.
Now that I have the pump out can I put 12V to bench test the pump?
Is 0.08 enough voltage to run the pump?
Thanks again Roger

thook

Not sure how much voltage you should be getting, but you can hardwire the pump to test it. That's essentially what you're doing when you run the test from the FSM manual. Which I would think would mean 12volts to the pump.

Speaking of which, I wasn't paying complete attention to your year of vehicle. I hope the procedure was applicable for you.

88yotadad

Yes the FP to +B jumper works. I printed off the pages but the pictures did not print.
Good info.

thook

Dandy....

88yotadad

I bench tested the pump and it ran. I nstalled the new pump bracket and pump. The pump will not pump and I assume it is not getting enough power.
I tested the wires at the pump and I only got 0.8 of a volt. I tested the power at the jumper wire and it is the same 0.8. I'm guessing that it must be a relay problem.

thook

The pump relay is easy to test:
http://personal.utulsa.edu/~nathan-b...96circuito.pdf

If it's faulty, an O'Reilly will have a good economic alternative to OEM......though, OEM would be nice.

WAIT!!! I have one used....Nippondenso. If you're interested, it's still in good working order. I'll retest it, of course, to make sure. Let me know and we can see if the part #'s the same.

88yotadad

I checked the open circuit relay and seems fine. What BI to get at or just even find.
where is the feul pump switch located.
Thanks again for help.

thook

The circuit opening relay is the fuel pump switch. And I agree...it's a *bleep*.

Sounds like you need to track down the wiring. I'll have to do a little homework before I can really be more help with that.

88yotadad

I guess I'll start following wires.
Thanks Roger

88yotadad

At my wits end as there must be a fuse or relay that I'm not finding. I tested the circuit opening relay and I test the EFI relay and I have tested the fuses in the box under the hood.
Is there a fuseable link in the wiring hareness?
Is there other relay that could stop the fuel pump?

Yodaforce

The only way to test a fuel pump is by fuel pressure. It can run fine out of the tank and electronically check out, but the true test is psi.

88yotadad

I'm not getting enough power to the pump to run the pump. I'm only getting 0.08 of a volt to the pump.

thook

There is a fusible link. Here's a wiring diagram from the FSM:
http://personal.utulsa.edu/~nathan-b...95efimainr.pdf

I know this doesn't actually show where it is or what it looks like...nor do I know where it is. I've never had to track it down. If you find it, I'd like to know. And, no...there's no other relay.

You said you tested the power at the jumper wire. Do you mean the jumper wire when installed at the diagnostic box?

88yotadad

Yes I tested the jumper wire and only had 0.08 of a volt. The same as at the pump.
What about the flow meter?

Yodaforce

A fuel pressure test guage available at most parts stores. All EFI motors have a test port. Get your power issue straight, then test your pressure.