1990 Q45 Fuel Pump O Ring...

[aliciaford]

Ok. We are replacing the fuel pump in my 1990 Q. The old fuel pump O Ring is approx 5.5" in diameter. It seems like its way too big... and also the pump did not come with a new gasket. Old one looks in good condition, just seems like its too big. Sound right to you guys?

[lino]

The fuel pump o-ring is sold separately and I believe it's part number 17342-01A00. It fits on a lot of different cars including the following model series:

A32 , CA33 , F31 , F50 , FGY33 , G50 , JPY32 , JR50 , P11 , S50 , V35 , Y34

[Rex]

If you have the time/means replace the O-ring now. If not you will likely have to replace it later when the smell of gas fumes arises .

[paranoidjack]

...and I believe it's part number 17342-01A00....

lino....was that from MEMORY????????

[Q451990]

You definitely want to replace it. Also, make sure you don't over tighten the screws that hold the assembly into the tank...

Good luck!

Heath

[elwesso]

agreed on all accounts. Tighten the screws JUST tight enough to be snug. They wont feel tight but by the time they do feel tight it will be too late and it will be stripped out.

You need to buy a new O ring, they are universal to nissan, head over to your nissan dealer and pick one up..

[maxnix]

Tighten in a star sequence per the FSM and Tangalora's excellent tutorial in IOM.

You must use a new O ring to avoid gas fumes, and you must not confuse old with new.

[Infinitiguy19]

I am suprised no one mentioned the fact that over time the rubber o-ring expands to fill any holes or space because of the fuel in the tank which causes rubber to expand.

I remmber when I had my 91 Q and my dad and I were installing a used pump (When I did'nt know what i know now) and we actually got the old one to fit some how. But we ended up going throught 10 o-rings till we finnally fixed thef fuel pump problem.

Basically when the fuel pump finnally "gave up" it was'nt the fuel pump that stopped running it was the Fuel Pump Control Unit (FPCU) that gave up (solder joints or the switch in there gave up). and we thought we bought a good pump so we installed it and no go. We took it back the guy grounded it and he showed us that it worked. So the FPCU was not grounding or providing enough power to the pump to run the specified fuel pressure when cranking. So we then grounded the pump our selves and skipped the whole FPCU. But the used pump out lived the car.

[Q45tech]

The 1997 and later has a large high wattage resistor in parallel*with FPCU so even if FPCU fails there is still some current following that allows the pump to reun at a slow speed.................takes a few amps off the FPCU so it should last even longer.

Consider the underhood resistor for AT solenoid as a possible suitable instrument to begin experimenting maybe 2 of them in parallel.

* Instead of jumping pump to ground jump it to ground thru a LARGE WATTAGE resistor.

[lino]

lino....was that from MEMORY????????

lol not quite . That would be Wes who has a memory like an elephant.

When I posted that part number I wasn't 100% sure it was the right one when I looked it up. I did verify it later though.

[greg_atlanta]

If not you will likely have to replace it later when the smell of gas fumes arises .

I've had that smell before, it's not pleasant. Replace it. (When pump was replaced by previous owner I think they used JB Weld instead of the O-ring).

[aliciaford]

Thanks. New Pump and Ring are in, and I should have replaced it sooner. It freakin rips. I forgot how much power it really had, I better order one for my 94 ASAP!!! It has 122,00 miles on it and I can feel a bit of hesitation and the acceleration is nothing like the 1990 now.

[elwesso]

amazing how the car runs when it gets enough "go-go juice"..