Fuel Pump Replacement

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Aus94Q45
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Joined: Tue Jul 23, 2002 5:52 am
Car: 1994 Q45

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Heard minor intermittent buzzing in the area of the fuel pump behind the shield in the trunk. It was not there this morning, but I suspect that the fuel pump may be starting to act up. No performance or running issues at this time. I have 90K miles in this 1994 Q.

However, in anticipation of things to come, how hard is it to replace the fuel pump with the tank in the car. I recall a differnt thread here stating that the rear seat, rear deck panel and trunk shield must be removed. After those are out how hard is it to undo and reinstall? Hour estimate?

Also I know that any fuel tank job is dangerous. Beyond removing the battery and attempting to release all static electricity, any other precautions??? I don't smoke and do not plan to start here!!! Ha!


landtodd
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Taking the rear package shelf out (have to take the back seat out to do this) allows you to remove the pump with the tank in-place. The pump goes up through the hole vacated by the package-shelf binacle. You work from inside the trunk.

It's easy, but if you've never done it before and you're slow (like me), take an afternoon, save yourself a grand (over -my- dealer's prices).

Be sure to remove the gas cap! Otherwise you'll do what I did and get gasoline all over everything from vapor pressure. Took about a week driving around with charcoal in the back seat to get rid of the odor.

Good luck!

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DAEDALUS
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Pull the pump fuse while the engine is running to reduce the fuel system pressure. Crank the engine once or twice after it stalls. I would throw down some towels around the base of the tank just in case and keep some disposable buckets handy. I consider a fire extinguisher nearby a must anytime I expose fuel.

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DAEDALUS
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If static discharge is a problem in your area then consider getting an ESD wriststrap from a computer store. Costs only a couple bucks. Wear it around your wrist and clip the wire to the frame. It'll keep you grounded at all times.

landtodd
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I have become *way* too complacent about working with fuel. It comes from living on Florida's North Gulf Coast (the "Big Bend"), where humidity is almost always 70% or above. (Mold spore capital of the world. Seriously.) Static is a real novelty here, and that's absolutely no excuse -- I should be more careful, particularly if I ever migrate to a drier clime. Thank you for the safety reminder.

Aus94Q45
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Car: 1994 Q45

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Excellent feedback -- as ususal! Thanks! On the static issue, we do not get too much down here in Texas, with the exceptions of Jan. and Feb. on cold dry days. However, you cannot play it too safe when working on fuel related components. One tiny spark will do the trick, especially with the higher octane that we all run.

The buzzing was abesent today also. However, I am keeping a close gaurd. Any thoughts on how long or how many miles a Q fuel pump lasts? This one has had the filter changed on schedule and is at 90K. How long did yours last? Did it die abrutly or die a slow sputtering death? (The one on my boat simply conked without warning -- 9 mles from the dock!)

mccluredude
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Joined: Mon Oct 28, 2002 3:56 pm

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I've read the average life of these pumps is near 80k. Also have been told that a bad pump can affect the fuel controller module which is a much more expensive fix. From everything I've read, it sounds like the fuel pump problem should be attended to as soon as possible.

I'm picking up my 94 Q45t tonight. I heard that buzzing in the trunk as well and it's the first repair on my list. I am a new owner starting today!

From what I've gathered on this list, a bad fuel pump creates more heat and can melt the soldered connections in the Fuel Controller module. The connections get hot, melt, and give intermittant stalling problems. Then when they cool down the problem goes away.

I've also read that rebuilt pumps or aftermarket ones don't have the same reliability as the OEM part

Let us know if you run into any snags replacing your pump. I'll be doing mine in the next week or so.

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DAEDALUS
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Did the pump today. It took me about 2.5 hours, which is pretty good for me (but faster than the dealer, based on what they charge!). It's been humming for who-knows how long. I looked at the controller connectors but no signs of burning or melting. Haven't checked the fuel pressure yet, but there is definitely a bit more kick in the pants. The tires are back to spinning in 1st. Ahhh...no more humming. I did notice that the pump is making a quiet, fast clicking noise, kind of like it's clicking on each revolution. Anyone else notice this? I'm thinking it'll quiet down after it breaks in a little. I can only hear it with the trunk open and my head near the tank.Thanks to everyone who's posted and emailed about this job in the past. Because of all the precautionary measures, I only got a trickle of a leak when I removed the flare nuts and metal lines, and I was well prepared with towels in place to catch all the drips. I removed the rear seats and deck cover, and it made access a bit more convenient, but does anyone know if the job can be done without removing the rear cover? Seems the recessed tray would prevent removal of the pump.

Now I'll just ramble a bit. I finished sooner than I thought I would, so I took the opportunity to work on my 85 Firebird. This week, the alternator belt suddenly began making the worst, most horrible screeching noise I have ever heard a belt make. It was LOUD.I propped the hood open and stood there looking at the engine for a few minutes with my girlfriend. Neither one of us wanted to touch anything. We remembered when we first began doing work on the Q, and how everything seemed so complex and advanced and impossible then, unlike the Firebird's engine bay. Now, 15 months later, everything in the Q's engine bay makes sense, is very well designed, and just plain seems right; in comparison, the Firebird's engine seems so crude and archaic (not to mention dirty). Case in point: the belts don't have any tensioners! Each peripheral belt-driven component is held on with 2 bolts; 1 on which the item pivots, and another that's fastened through a concentric slot. I loosed the bolts and then I had to PRY the alternator away from the frame with a crowbar to induce tension in the belt, and then simultaneously tighten the bolts. WHAT? The designer's obviously didn't expect the car to last very long. The odometer will roll over at 100k, not 1M like on the Q. Only 2,000 miles to go, and I'll be happy if it actually gets there. The Q get's spoiled rotten. The Firebird get's Chevron oil maybe 2-3 times a year, regular gasoline in the tank, and very little else.

911/Q45
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The difference in engineering is why the Q cost about 3 times what the Firebird cost. I've always believed that Nissan subsidized the Q when it first came out to break into the market. I wonder what the real price should have been and what a similar quality car would cost now, as I don't think anyone makes one. The Q was probably built better than it needed to be and the manufacturers figured that out.

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greg_atlanta
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Car: 2008 G35 Journey Sedan, silver/black (no sunroof), 1992 Q45 (in a past life)

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DAEDALUS wrote:Did the pump today..... It's been humming for who-knows how long. I looked at the controller connectors but no signs of burning or melting.


That's good to know. My pump has been singing a little bit now and then. Just takes a full tank of gas to shut it up!

I'm convinced it's just another cold weather gremlin. I blame cold weather on everything..... my misbehaving CD changer, out of balance tires, driveshaft (better since replaced), suspension squeaks...

My Q is happiest above 60 deg F.

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RobHakari
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is there any certain procedure to taking out and replacing the fuel pump? would be good to know this so i can see if I can do it on my own instead of paying outrageous dealer costs.

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Touchdown038
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Taking out and replacing the fuel pump is one of the easier jobs I've done on my car. Unplug the neg. battery cable, go to the trunk, take off the inspection plate, unhook the connector and fuel lines, unscrew the pump assembly, and pull it right out. Unhook the pump, put the new one on, and screw it all back together, making sure you don't mix up the fuel return and send lines. (Putting the fuel lines back on was the biggest ***** of all, because there is very little space to work.) After that, plug in the neg cable and turn the key to On and listen for the hum of the fuel pump pressurizing the system. If you hear that, you're good to go :)

EDIT... This procedure was for my 240, I would assume it's close if not exactly the same on the Q.

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DAEDALUS
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The Q is a little harder. The seats and rear shelf need to be removed. Take out the bench first, and then unscrew the seat back and pull it forward to remove the shelf. The recessed compartment needs to come out to give enough room to remove the pump. The fuel pressure needs to be zeroed, and even then expect to have fuel gush out of the fittings when they're loosened, so be ready to clean it all up on the spot. Take whatever static precautions are prudent for your environment. Careful when pulling the pump--the entire assembly is kind of C-shaped, and needs to be turned as it's lifted to clear the tank.

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RobHakari
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hmm... ok... doesnt seem too bad. i think ill attempt it on my own... cause i cant wait, that humming was more persistent today.

how much does Scottsdale sell fuel pumps to NICO members for?

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Touchdown038
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You probably don't need to replace it for probably another 20k miles as long as it's working fine. Mine went at 148k, but if you wanna get it outta the way then go for it. The 91 procedure should be about the same as the 89 procedure I posted above. And one thing I forgot to mention: release the fuel pressure. Pull the pump fuse, start the car and let it die, then crank over a few more times. If you don't, you'll let the fuel pressure out when you pull the hose off the pump, and it'll shoot all over your tank and part of your trunk, and it'll make your car smell like gas for a few days. And the chicks don't like to smell the gas when you're cruising ;)

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DAEDALUS
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Pump is $235 from Scottsdale.

Q45tech
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Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl

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Have seen brand new fuel pumps destroyed in less than a year from dirty new gasoline or not cleaning the bottom of the tank.......be sure to do the job with less than 1/4 tank if possible so you can see the bottom cup where the strainer sits.

Always change you fuel filter ever 30,000 miles or 2 year.......every year is better.It doesn't take more than a spoonful of dirt to clog a filter. The aded resistance raises the pressure [work required] to push the gas thru the filter thus the pump draws more current and works harder.

This can be checked [proven] by measuring the current with a dirty filter then changing it out and watching the currrent draw drop. Never done by anyone but me since the warranty is only 12/12k so most last that long regardless of the stirred up dirt.

Aus94Q45
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Multi speed pump? That is what is in the Q, and it is computer controlled. I doubt that an after market in-line would work with the fuel control system.

Q45tech
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240 sx posts were deleted because on wrong forum

rrack
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Just wondering what are some other symptoms of a bad pump???? I know on Fords, they can sometimes work fine and sometimes not. Mine acts fine, except for the humming. Recently, the car has stalled while my wife was driving. She coasted to a stop and simply restarted it and said that it appeared fine after that. Does this maybe sound like a bad pump? I know it has been getting a little noisy back there...140K...

Just taking a poll before I roll some pennies to buy a new one... ;)

robert

Q45tech
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Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl

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Over and over the same thing: The worn pump draws more than expected current melting a solder connection in the pump speed controller when the ecu [or owner] shuts down the pump the solder solidifies and the process starts all over .......... usually happpens after a crank or an acceleration when the pump draws the most current.

Very Very common...........owners who put off changing the pump just stress and stress the controller till it too will fail permanently!

$550 now or $1100 later plus a $100 tow off the Interstate in a rain storm.

Hate to see people wait so long as the money could be better spent on real tires or a brake job or half an ac repair.

Qdog
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Car: 92 Q45

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160k Q45, I have no record of a fuel pump change. I can't hear it inside the car (except for high speed pressurize for 5 sec at at start-up), but I can hear a steady hum at idle with my head in the trunk. Is this normal ? Should I change it anyway with this mileage ? I'm about to do the plenum job, it would be a good time to do the pump too, if necessary. If there is visible crud in the fuel tank, what is the best way to clean it out ?

Qdog
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I never let the fuel go below 1/4 tank, I attribute my long fuel pump life to this (and good luck with clean gas). All gas in my area is 10% ethanol, the Q really runs well on Holiday 93 octane low sulfur. I'm curious how it would run on pure gasoline.

Q45tech
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Ethanol produces lower BTU than gasoline since it is already partially preburned [thus the oxygen in its formula]..........3.5 to 4.5% less heat will be produced in burning an equal volume of the 10% mixture.This could roughly translate to 3.5-4.5% less power at WOT.

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Jesda
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Took me two weeks to get the horrid gas odor out of my Q45. Leather reconditioner and vaccuuming helped, as well as a generous helping of Febreeze. Also left the car with all windows open overnight. Wish I knew about charcoal.

You could throw a box of kittens in the trunk to make them breathe in and convert the odors to something a little nicer when they breathe out, but you'd have to get another box of kittens after they died. (j/k)

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RobHakari
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Woohoo! Ordered my fuel pump from Joe today(woulda done it sooner but i called like 5 minutes too late on saturday).

If you read this Joe, thanks

rrack
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Just replaced the pump & filter. Thanks to Scottsdale once again! The dealer here wanted $600. Joe had it for $235! Jeez! I think it musta been the original filter too. I could barely blow through it. Anyway, it was a fairly easy job. You just have to make sure to remove the rear seat and deck cover to (easily) pull the pump out. Only took about an hour. I checked the module and everything looked fine in there...no burns or broken solder connections. I also tested for the 3 different module resistances. From what I could tell, it checked out.

I test drove it and now I have to listen real real hard to even hear the pump. It kinda sputtered for a second when I first took off. I'm hoping that it may have just been air in the lines. I'll see tomorrow on the way to work. If not, off to the diagnostic machine.

robert

p.s....still no receipt from T3...

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RobHakari
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argh. i forgot about a fuel filter. oh well... ill see how mine looks and then replace it in a few weeks if i need to(prolly will)

rrack
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AW CRUD! It stalled again! I drove it all over yesterday and it drove perfectly! My wife takes it to work this morning and it dies as she pulls into the drive where she works. She said that the A/C shut down then stalled. She said that she cranked it right up again and everything was a ok. She drives about 15 miles each way. Each time it has stalled right when she either gets to work or just about home. i.e. after thoroughly warmed up...I'm stumped. I wannat figure it out b4 I shell out more dinero for a diagnostic check here at the dealer.

I'm gonna do some intense service manual reading tonight to find some possible causes. I don't know if it still may be that pesky pump module. I thought I checked it out right. I may pull it back out and recheck the solders and resistance readings again. Oh well. Is this a symptom of a bad module?

Robert

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DAEDALUS
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I would think its possible...like Q45tech detailed, the solder melts after it heats up enough, causing problems, and then solidifies after shutdown. Can you swap cars? You can get a fuel pressure gauge for about $30, and 10' of fuel injection hose for another $30. Run the gauge to the windshield and see what happens when the car stalls.


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