Replacing Fuel Pump

[Razor]

Hi
My car won\'t start
checked for spark thats good
checked battery
but no fuel spitting out of the new fuel filter when I crank the engine so I decided its the fuel pump
cant hear any noise coming from the fuel pump or engine when I put the key on the \"ON\" position or by cranking

Can anyone please walk me through replacing a fuel pump

I had  the tank cover off the one with 4 screws

now I can see round tank cover with multiple small screws and wires on it.

When I take the screws off do I just pry the round plate off to get to the fuel pump?
is there a proper way of doing it?
so just pull that off and how do I get access to the fuel pump?

I\'m short of cash so trying to do it myself for now....

I called up a local auto parts store and a replacement fuel pump cost AU$190

I called up a local wrecker/junkyard and they said I can have one for AU$45

Is it safe for me to replace the pump?
I checked the fuse and thats good

Please I need you advice

thanks

[vg30e_x2_200sx]

There is a known problem with the sending unit on these cars.

(the second plate with all the screws and the wires going through it)
 
The insulators fail and either the ground wire touches the cover plate and the pump stay runnig, or the posative touches and blowes the fuse.
 
I mension this because even though your fuse is good and you don\'t have either of these symptoms, disturbing that top plate to replace your pump could very well be the thing that is needed for it to happen.
 
I know that you won\'t want to hear this, but it would be VERY bennificial to replace that now and avoid having to do this twice.
 
Unfortunatly the only source for it is the dealer and you\'re looking at about $150.
 
You are corect in the assumption that removing the reamining screws will allow you access to the fuel pump. All you have to do is lift and manuver the sender/pump assembly out of the tank (not that difficult).
 
When you install the new one you will need a new o-ring. Make sure to clean out the ring land thoroughly. You will need some white lithium grease to apply it to the new o-ring to help it seal properly. It would also be a good idea to get all new screws for the top plate because they are aluminum and strip very easily.
 
If you don\'t use greae on the seal it won\'t seal properly and you\'re gonna be smelling gas all the time. (been there, done that)

[seishuku]

You know, I was thinking about that issue with the sender... Couldn\'t you (if it\'s still in decent condition) just put epoxy (marine grade?) around the terminals on both sides? So even if the insulators fail, it wouldn\'t matter since the epoxy will hold it in place.
:dontknow:

[Ron Amundson]

Nissan used a cheap elastomeric seal that goes around the feedthrough interconnet, in addition to another one that mechanically supports it. It often times disintegrates due to vibration, and long term exposure to fuel additive vapors which the S12 was never intended to run on.

It is possible that the center conductor might short to the cover plate, due to this elastomeric fitting, despite the top caps being covered with epoxy. If its inside the tank, no problem, sparks are no big deal there. It its external, and you have another one that is leaking fuel vapor, big bang is possible.

They also did not properly terminate the connections.... over time, the wires will corrode, and they may well break off inside the cover caps which were molded in place. Then again, the S12 is probably well past its design service life, so it probably was an acceptable compromise. Chances are, 20 years ago, vapor migration through molded on plastic was considered a minor problem, if it was even recognized outside of the military arena.

I machined new feedthroughs, made out of Delrin, and used nitrile orings for sealing. I also changed the terminations to prevent corrosion. Considering a new plate is only $150, its wasn\'t the most cost effective, but having had to replace these a few times, I decided to fix the problem once and for all.

I pulled my fuel pump notes, and made a pdf file. I intentionally left the design documents for the spacers, orings, and terminations off, as I don\'t want someone to make a mistake and have a fire. A minor error in dimensions, or material selection, could have serious consequences, and I want no part in that.

The document has also not been checked for accuracy, especially on the third page, as my intern put it back together for me, so I didn\'t get a chance to see if it was correct or not. I could just see him not following the directions, and it works.... I just don\'t know. However, you may find the operation specs and wiring to be helpful.

If you do still want to use epoxy, the marine stuff may or may not hold up to fuel vapors. The original, not the fast curing JB weld does. It also withstands gasoline in liquid form in one isolated long term test. It is not acceptable for pressurized sections. We could never get it to withstand more than 5 psi before leaking, unlike high dollar industrial epoxies. The other problem with an epoxy repaird, is its hard to properly prepare the surface, especially when you have a unknown plastic cap, and a likely corroded top cover. I don\'t recommend it.

Ron

[Razor]

this morning I replaced the fuel pump and the top cover (sender) but I tried to start the car but still wont start.
Asked someone start or put the key on the ON position and I listening if fuel pump is working but I dont hear any noise at all

I checked the fuse in the fuse box but that wasnt blown

Any more advice please....

Im stuck and no more ideas...

Cheers

[vg30e_x2_200sx]

There is a relay located at the back of the car behand the rear plastic panel. I believe it\'s brown, but don\'t quote me on that. That would be the next place I\'d look.

[Razor]

where specifically at the back of the car? right side near the sending unit\'s 2 plugs? under that plastic pocket?
or near the locking mechanism?
what does it look like? small square like headlight relays?

[vg30e_x2_200sx]

it\'s under the very rear panel that covers the tail lights on the passenger side. There are two relays there. I think it\'s the one towards the center of the car (closest to the liscence plate).

[Alex Frost]

it\'s under the very rear panel that covers the tail lights on the passenger side. There are two relays there. I think it\'s the one towards the center of the car (closest to the liscence plate).

The one closest to the licence plate is brown...

[Razor]

so is it outside the hatch or inside the hatch/boot?
its behind those plastic cover panel for the tail light?

[Alex Frost]

It is about 30-40 cm\'s from the inner edge of your driver\'s side rear taillight. It is hidden by the same cover that covers yout taillights; and licence plate lights...

[vg30e_x2_200sx]

It\'s inside under the plastic.

[Razor]

thanks I\'ll have a look at that

[Razor]

are pintara\'s fuel pump interchangeable with our cars?

[Razor]

are you gys sure there\'s a relay behind those plastic panel? in the hatch

cos I took everything off and I can see any relays