abby356

I have a 1992 4runner 3.0 6cyl 3VZE that sat for 7 years with gas in tank and not strated during that time. It was running fine when parked, but needed a fan pulley bracket and I just did not deal with it until now. Put in new fan pulley bracket. I had 8 gallons of the 7 year old gas and added sea foam and filled tank reat of way with new gas.


Can get it to run fine with starting fluid, but not on its own. Emptied all the gas mixture I had made (old and new mix) by siphoning (got about all as siphoned 17.X gallons) and re-filled with new gas and another can of sea foam. Still runs fine w starting fluid, but not on its own.


Jumped the FP and +B and no pump sound. Disconnected cold start injector fuel line and no gas comes out when cranking, running using starting fluid or when fuel pump jumped at diagnostic terminal (FB +B). Went to fuel pump connector under passenger seat and got 12.2 volts. Pushed the AFM flap while key ON and heard relay click at each flap push.


Does all this mean my next step is to replace fuel pump? Are there other circuits that could cause pump not to run when have FP and +B jumped and have 12 volts at connector? For example, to get starter to engage I do have to wiggle shifter handle occasionally (very occasionally) to get neutral start switch to recognice (?) the car is in park, and have for years, but could the neutral start be interfering with fuel pump coming on?


If the good violtage to connector at tank means fuel pump is bad I am going to do the cheap trick of opening that access port up with tin snips or jig saw and getting at fuel pump that way. Any thoughts/answers before I do this? Got all my diagnostic ideas from this forum and I thank everyone!

wallytoo

iTrader: (1)

with the jumper connected and ignition on, tap or bang the pump access cover of the tank a few times. this might get the pump to start working. you might still replace it, but if it gets it to work, you'll know the pump was the issue.

muddpigg

iTrader: (1)

Did you replace fuel filter?? When you replace it run line from tank to filter to container. Try to start to see for getting fuel to filter. Unless your hearing is way better than mine (which is very probable) you won't hear a Denso fuel pump run, especially in tank. Also can try to hot wire pump to battery. Then if nothing yep pump. Or clogged line. I replace pump and turned out to be a damaged wire. Was getting voltage to harness but not enough. But 12.2 v should be good

wallytoo

iTrader: (1)

the running pump is audible, even the denso, with ig on engine off & test port jumpered.

scope103

FP goes straight to the fuel pump; the PNP (park-neutral) switch is not in the circuit. So unless you have a broken wire between FP and the pump, 12v on FP should make the pump run (and it should be audible is a reasonably quiet area).

The only way to check if FP is connected ALL the way to the pump is to pull out the pump, in which case you'll want to replace it anyway.

abby356

Thanks All! Still trying to make sure pump needs replacing or if some other electrical issue. So far I have done these things:


As per original post: Jumped the FP and +B and no pump sound. Disconnected cold start injector fuel line and no gas comes out when cranking, running using starting fluid or when fuel pump jumped at diagnostic terminal (FB +B). Went to fuel pump connector under passenger seat and got 12.2 volts. Pushed the AFM flap while key ON and heard relay click at each flap push.

Now I have also used a multimeter:
Fuel pump resistance is 1 ohm.
Negative side of pump connector to body ground is 0 ohms.
Positive side of pump connector to body ground is 1 ohm (same as pump resistance above).


Oh, and also ran jumper cables from battery to pump connector to power pump directly (for sure) and no pump sound and no fuel coming out of the disconnected cold start injector fuel pipe.


So in another post Hadmatt54 wrote that pump resistance should be around 37 ohms. Also wrote that the + and - pump leads to body ground should go to infinity...as you see above, I got 0 on negative pump lead and 1 ohm on positive lead.


So, considering scope103 reply (thanks!) seems like 12 volts to pump connector under seat and now these resistance readings mean pump is bad? Thanks

abby356

Oh, one last thought is that the positive wire on the pump side of the connector is grounded? But it sure looks like a short wire and like it goes straight into tank. I have probably revealed here that I am amateur w multimeter, I can test, but not always sure of meaning of results! That the check of pump's + lead to body ground gave 1 ohm means nothing to me...should it? The check of pump's negative lead to body was 0 and I was happy w that...right?

wallytoo

iTrader: (1)

did you try to tap/bang the cover with the ignition "on" and the Fp jumped? that can get a pump that is slightly frozen/stuck to release and start pumping, which would confirm that the issue is with the pump.

abby356

Yes, thanks.

rattlewagon

If you jump power directly to the pump, will it turn on?