problem after changing fuel pump

[rahiel aziz]

my friend just changed fuel pump in his 92 q according to the instruction given here.everything went smoothly car starts but fuel gauge is stuck at empty "E" even he filled up gas tank but the gauge is still showing empty.according to him that what he did.1-took out fuel pump fuse and let engine run till it stopped.unhooked the battery.2-remove trunk partition.didn't need to reomve the back seat.than unscrew the two screw on the pump and five holding it to the tank.took out old pump checked the connection on module no crosion.put in new pump, reverse all steps and started the car.but gauge stuck at E.so what he overlooked

[Q451990]

There's a gauge sending mechanism that's connected to the pump assembly. Basically a float attached to a variable resistor if I remember correctly. Maybe he didn't get it re-installed correctly, broke it, or the electrical connection for it didn't get made. I've heard they're very delicate.

Heath

[landtodd]

It sounds like the in-tank float and/or sender. They're delicate, and it's really easy to bend something on the way in or out. Also, the float may have been punctured while it was out, now possibly full of fuel.

It's either mechanical damage or the sender isn't hooked up after all. An ohmmeter can tell whether or not the thing is making electrical connection inside the tank. He'll have to look up which terminals are which, where to disconnect them, and what resistance to expect. (Sorry, it's been a while since I've fooled with the fuel pump. Write if he needs more info.)

If he got the package shelf off without removing the back seat, his Q isn't assembled like most!

Car runs, right?

[911/Q45]

He probably damaged the float by bending it around to avoid taking out the back seat and package tray. That's the sort of thing I always do, short cut that turns out to be the long expensive way!

[suhailkhan]

hi, i am the person who changed the fuel pump in my 92 q45, i will explain what i did . First i took the back seat out and i saw that there was metal tray behind the seat and i had no idea how to take that out. So i went through the trunk. I took off two hoses first and then five screws which were there to hold the round cover. When i opened the cover , i took the part which had the fuel pump resided in it. There was this small plastic box which was attached to the bottom of the fuel pump, I'm not sure if i damaged that plastic part or not. Please help me out and let me know what could be the reason. Also, even if i broke that part how much am i looking to fix it, and if i could fix it by myself.

[suhailkhan]

and yes the car runs fine.

[911/Q45]

After you take out the rear seat cushions and the package tray you can remove the storage box under the package tray to access the fuel pump from above. That should allow you to pull the pump straight up without damage. You'll have to pull it out and look at it to determine repairability. I would consider repair to be possible, but unlikely. If something is bent you can straighten it, but if broken replacement is probably the answer. After you've gone to the trouble of replacing the pump, it would be a shame to have a nonfunctional fuel gauge.

[landtodd]

I will wager you lost the float, compete with arm, in the fuel tank, where it's probably still bobbing around. If you leave the tank in place (please leave the tank in place!), the following things must come out to look into the tank and see:

1. the rear seats2. the package shelf3. the plastic "box" under the package shelf

Fuel pump *assembly* (take the whole thing out!) goes straight up into the hole vacated by the plastic box in #3, wiggles out into the trunk.

You're going to have to take it apart at least this much to figure out what happened. You might want to read previous posts again. I trust you have the factory book so you can see what the fuel pump assembly is supposed to look like!

Extra tip: If you spill gas under the tank, it will smell like hell. Put some charcoal brickets in the car. They do a great job of soaking up the gas smell (voice of experience)!

[greg_atlanta]

My fuel sending unit goes crazy sometimes (predictable pattern now) but to be safe I fill up every 250 miles in the city and every 300-350 miles on the highway. I just reset the A trip odometer with each fill up.

The part is around $125.

[rover3l]

I wish I had seen this post before I changed my fuel pump as I have exactly the same problem. The fuel gauge is stuck at Empty. Did you every find out the cause. I realize I am going ot have to take the pump out again to find out

[rahiel aziz]

yes my friend finally fixed it after got tired of gussing how much gas left in the tank.did u take the back shelf out it very important otherwise u will bent the floater arm.do it again from the top.good luck

[rover3l]

Initially I did not take the rear shelf out and I tried to remove the pump soon realizing it would not come out this way. Then I remove the rear shelf and the compartment tray and lifted the pump out vertically into the passenger compartment. I may have bent the float unit. What did you specifically do to fix it.

Thanks

David

[tangalora]

> Initially I did not take the rear shelf > out and I tried to remove the pump > soon realizing it would not come out> this way. Then I remove the rear > shelf & the compartment tray & lifted > the pump vertically into the > passenger compartment. > I may have bent the float unit.

As tempting as it is to remove the fuel pump from the trunk room, you MUST also either remove the rear seats & package shelf & storage binacle; or you must drop the tank (most prefer the former).

While you can see all the parts and diagnose your fuel pump & fuel pump control unit problems simply by removing the 7 black #2 philips screws holding the flimsy fiberboard bulkhead between the rear seat back and the trunk ... this forum has clearly spoken that you should NOT REMOVE the fuel pump assembly from the trunk.

See the attached photo of my Infiniti Q45 original fuel pump (125K miles) squirming out of its cocoon through the foot-long rectangular opening left by the removal of the package binnacle (aka package basin).

[Trung1130]

Hi Rachel,

One last question regarding the fuel gauge meter arm with the plastic bubble thing attached to the fuel pump.

That arm was free swinging when I took it out of the gas tank but when i checked to see what was wrong with it i realized it was no longer free swinging. I thini that is the problem but how do i ge tthat arm to be free swinging again?

Thnx