Fuel pump replacement

[ceningolmo]

My fuel pump is noticeably humming. How big of a threat is it that the failing fuel pump will destroy the Control Unit? Is this type of a problem typically a short term failure (as in, within 2 weeks of hearing the pump), or do I have some time to drive the car while I order parts?

Also, do I need to go through the whole process of doing diagnostics on the various components of the fuel system?

I read this thread (zerothread?id=6268&page=2 ), but much of that was related to finding the actual problem for a Q that was not starting. If my Q is currently running and starting without problem, is it safe to assume that simply replacing the fuel pump is all the preventative maintenance that is necessary?

Finally, if I am replacing the fuel pump, is there a kit of parts that I need to order? The thread talks about some of the parts necessary for the Control unit.... I just want to make sure that I order everything I need. It sounds to me like the fuel pump and the o-ring are the only parts I need to order. Is that correct?

Again, thanks for the help.

[maxnix]

In a word, search first, please.

The definitive post is Tangalora's in Infiniti Mechanic Forum.

[ceningolmo]

You mean this one....

zer...age=2

I already quoted that link in my original post. If you are referring to another post by Tangalora regarding the fuel pump, I did not find it while doing a search.

I don't bother posting unless i have done some reading. Unfortunately, much of the readiing I have done is over my head. So, even though I spent an hour reading a variety of posts on the topic of fuel pump replacement, much of the information was beyond the scope of my experience or was not applicable to my particular situation.

Thus, why I posted my understanding of the situation coupled with a request for clarification.

[redmanfx]

If you drive to long with a humming fuel pump you WILL eventually fry your control unit. Control units are not cheap, so it's best that you replace your fuel pump as soon as you can with a new one.

NEVER EVER buy a used fuel pump under any circumstances!!

It's just one of those things you do not buy used. Most of us have driven with a humming fuel pump for a period of time, but drive to long and kiss $350 bucks goodbye for a new control unit to go along with a new fuel pump. You can get a good preowned control unit, but why if you simply change your fuel pump.

Here's a Hint to help the pump last as long as possible. Never drive with less than half a tank of gas. Keep that pump submerged.

You can order the pump from Joe at Everything Infiniti and it comes with what you need. It's not to expensive, but well worth getting rid of the noise.

red

[ceningolmo]

Well... I have been inadvertently keeping my tank on the top half. I didn't know this would help with the fuel pump. I am just trying to keep the tank full while fuel prices are dropping!

Thanks for the info... it was all the help I needed. I will contact everythinginfiniti.com in the next few days.

[Rex]

From the thread you posted, she walks through the process (without pics ) pretty thuroughly.

8. Remove the rear seats, rear sundeck shelf, and rear package binnacle:

REMOVE REAR BENCH:- Move the front seats forward as far as they will go and tilt thefront seat backs forward as far as they will go to obtain working room.- Locate the two black clip extensions on the rear seat floor area andpull out those two black clip extensions simultaneously pulling up onthe leading edge of the rear seat bench to lift it upward and out.The rear seat bench removal requires no bolts to be removed.There are only four clips in the leading edge; and two clips in thetrailing edge of the rear seat bench to take into account for removal.- Scavenge the $1.35 (on average) in loose change under the rear benchthat the federal government suggests wreckers earn per car on wreckedcars.

REMOVE REAR SEAT BACK:- Pop out or pry out (with a thin flathead screwdriver) the four bluesolid butterfly anchor clips from the leading edge of the rear topsidesundeck where the sundeck overlaps with the rear seatback.- Remove the two rear headrests by pressing the driver-side knob undereach & simultaneously lifting upward until the posts clear the seatback.- Push down the rear seat armrest and pull back on the vertical backingwhich is velcroed to the steel bulkhead behind rear seat back.- Remove the two #2 phillips screws behind this velcroed rear armrestcompartment.- Remove the four #2 phillips screws holding the U-brackets at thebottom of the rear seat back.- Pull up the rear seat back vertically, to clear three reverse-u-shapedwire brackets from their u-shaped metal brackets in the rear bulkheadmetal wall. This should remove the seat (except for the seat belts).- Pull out the two side rear seat shoulder belts as far as they will goand jam a pen or other object to eliminate the return tension.The seat belts will be less of a nuisance if you perform this task.- Flip the rear seat back (still attached by the seat belts) upside downso that the foam side is facing the front & the leather side is facingthe rear and the headrest portion is on the floor of the automobile.

REMOVE REAR UPPER TAIL-LIGHT & REAR SUNDECK:- After removing the three blue solid butterfly clips on the leadingedge of the rear sundeck ...- Pull toward the front and upward on the rear upper tail-lamp housing;and disconnect the rear upper tail-lamp harness connector from the rearupper tail-lamp connector. Remove the rear tail lamp housing.- Pull up on the rear sundeck everywhere you can to unclip the 11 solidwhite anchor clips (4 equally spaced in the rear, two in the middleon each side of the package binnacle, and 5 near the front of thesundeck shelf, three of which are closely spaced near the middle frontof the sundeck shelf and the other two nearer the outside edges).- Collect all anchor clips in a zip-lock bag marked "rear shelf".

REMOVE REAR SUNDECK PACKAGE BINNACLE:- With the rear upper tail-lamp & rear sundeck removed, unscrew theseven #2 phillips screws holding down the black plastic rear sundeckpackage binnacle (aka storage compartment basin).

Note: This rear sundeck storage binnacle is the key to removing thefuel pump since the fuel pump (with the attached fuel pump float,fuel pump housing, fuel pump level gage, etc.), can only come outundamaged through the rectangle left by the removal of this rearsundeck storage binnacle (aka package binnacle).

Note: Almost none of this removal procedure is explained in the factoryshop manual.----------------------------------------------------------------------------9. Remove fuel pump assembly from the top of the fuel tank from the trunk:

FROM THE TRUNK:- Disconnect the blue male fuel pump connector from the blue femalefuel pump harness connector.- If you haven't done so already, bleed pressure out of the fuel systemby cranking the engine with the fuel pump fuse (driver side dash, byyour kneecap) removed. Also remove the fuel tank inlet gas cap.Have a large hotel towel handy because it's inevitable that fuelwill leak as you remove the fuel pump assembly from the fuel tank.- With a 19mm open-end wrench, remove the two 19 mm tubing nuts holdingthe metal fuel pump outlet and vapor lines to the top of the fuel pumpassembly. Be careful not to break the three-line plastic separator(as I did) when bending the rigid metal fuel lines out of the way.- With an 8mm box-wrench or a three-inch stubby #2 phillips screwdriver,remove the six 8mm bolts holding down the fuel tank assembly coverplate to the fuel tank.- Gently pull up on the fuel pump assembly taking care to prevent thesix-inch black rubber O-ring from falling into the fuel tank.- From the trunk, twisting gently as needed through the rear sundeckshelf package binnacle opening, remove the fuel pump assembly.- From the rear seat area, look down into the opening left by theremoval of the rear sundeck package binnacle and inspect the fueltank for debris (mine was as clean as a galvanized chambered whistle).----------------------------------------------------------------------------10. Remove the fuel pump from the fuel pump assembly:

OUT OF THE CAR:- Pull out the two one-inch brown plastic alignment clothes-pinsin the fuel pump wing bracket.- Remove the two #2 phillips bolts bracing the fuel pump body to thefuel pump assembly.- Remove the one #2 phillips bolt holding the fuel filter sock to themetal fuel assembly (and push out the alignment tab).- Remove the #2 phillips bolt attaching the power wire and the #2phillips bolt attaching the ground wire to the fuel pump itself.- Gently force the fuel pump motor black rubber wings out of theirbraces in the fuel pump assembly leaving just the fuel hose attached.- Once the fuel pump wings are outside their slots, use pliars toopen the spring hose clamp on the plastic fuel pump outlet nipple.- Remove the (now unattached) fuel pump from the fuel pump assembly.- Compare the old fuel pump (in size & shape) to the new pump (thetwo fuel pumps should match exactly).- The replacement follows the reverse procedure.

Note: I purchased a new fuel pump from a parts store for $312.oo whilethe Infiniti dealership listed the fuel pump for $320. TheInfiniti dealership sold me the six-inch fuel pump O-ring for$13.oo (all numbers include tax). I noticed, afterward, thatonline, I could get the same pump (including the six-inch O-ring)for $235 plus shipping & tax. Go Internet, if you have the time.----------------------------------------------------------------------------11. Remove the fuel pump control unit for replacement or repair:

FROM THE TRUNK:- From the trunk, on your left side with your head facing the driverside rear fender, with your right arm through the opening left by theremoval of the rear sundeck package binnacle, place your index fingeron the topside location of the bolt head for the two bolts holding thefuel pump control unit bracket to the underside of the rear sundeck.- Have a partner mark the location of the two bolt heads (the actual boltheads are buried under 1/8th inch thick rubberized soundproofing material)using whiteout or other suitable marking on the black gunky material.

FROM THE REAR SEAT AREA:- With a small paring knife, cut out the rubberized gunky black sound-proofing material on top of the two 10mm bolt heads.- Use a 10mm box wrench to remove the two bolts holding the clamp onthe underside of the package shelf. Note that the clamp itself formsa U, with one portion of the bracket above and one portion below themetal horizontal sundeck shelf.

BACK IN THE TRUNK:- Check that the fuel pump control unit (white, female) harness connectoris disconnected from the fuel pump control unit (white, male) connector.- Remove the fuel pump control unit (with the bracket assembly attached)by pulling it toward the rear of the car, and downward.----------------------------------------------------------------------------12. Inspect, repair, or replace the fuel pump control unit:

OUT OF THE CAR:- Remove the four #2 phillips head screws holding the top plate(with bracket assembly) of the fuel pump control unit.- Remove the four #2 phillips head screws holding the bottom plateof the fuel pump control unit.- Inspect the wiring everywhere; notice any charred or burned areas(my ground wire on the bottom right (terminal side, tab on top) of thewhite male fuel pump control unit connector was charred a bit.- Also, there was infinite resistance between that bottom-right maleterminal and the corresponding printed circuit board connection(marked #4 on the PCB) on the underside of the printed circuit board.- I used a 25-watt soldering iron & a blue solder sucker to vacuum upthe solder around that #4 pin and I re-soldered that ground pin.- I also added a two-inch patch of 16AWG copper wire, soldered to that#4 pin and to all the connections on the printed circuit board I couldidentify as being that same ground connection.- Test with a ohm meter that the resistance for that one ground leadis near zero; and that accidental shorts to other traces did not occur.- Replace the now-repaired fuel pump control unit in the reverse orderof removal.

Note: Do not power-up the fuel pump control unit out of the car as theholding bracket supplies the main ground for the fuel pump controlunit itself.

Note: The #4 terminal is the ONLY terminal on the male white fuel pumpcontrol unit connector which is surrounded by EMPTY pins in thewhite female fuel pump control unit harness connector.----------------------------------------------------------------------------POST MORTEM:

THINGS I LEARNED THE HARD WAY:- Basically, I should've replace the fuel pump at 100K miles!Apparently they all eventually go bad. I should have also listenedfor the now tell-tale hum (I never even noticed it before).- Also, once before, about six months ago, my car would not start forabout an hour; and then, all of a sudden, started. At the time, Ichalked it up to cylinder wash (loss of compression due to gasolinewashing the oil off the piston walls causing rings to temporarily notseal); but now I realize it was probably the fuel pump control unit#4 pin solder heated up and, when it cooled, it re-connected itself.- It was recommended we should fill up when just about on one quarterof a tank (or so). The (unsubstantiated) argument states that the fuelpump heats up, causing more current draw (how?) which causes the solderconnection on the fuel pump control module ground circuit to heat upwhich, if it melts, can cause the open circuit that I found in mine.- The new six-inch fuel pump O-ring looked EXACTLY the same as the oldone (condition was imperceptably different). So much, I ended up mixingthe two accidentally, and I couldn't tell them apart. Be advised.- The new pump made almost NO SOUND. I didn't even realize that untilI had replaced it. Even with the full-power jumper bypassing thefuel pump control, the new fuel pump hummed vastly less than the oldfuel pump hummed.- The current draw and resistance measurements of the old fuel pumpand the new fuel pump were almost the same; so do not rely on thesefigures as a diagnosis test (listen for hum or check your odometer):OLD FUEL PUMP: NEW FUEL PUMP:0.9 to 1.1 ohms 0.6 to 0.8 ohms (from the blue male FP connector)5.6 to 5.8 amps 5.8 to 6.7 amps (with the FPCU bypass to ground)- The factory shop manual makes NO MENTION of the quick and easy testjumpering the fuel pump control unit harness connector to ground.Instead, the factory shop manual walks you through an apparentlyunnecessary lengthy step-by-step debugging process requiring the useof a three, four, and then a five wire jig to debug the fuel pumpcontrol unit. Don't overdiagnose. Just use the jumper and if thefuel pump operates, then replace BOTH the fuel pump and the fuelpump control unit (or repair the fuel pump control unit).- For the longest time I was confused about the various debuggingprocedures in the factory shop manual. What cleared it up was therealization of all the proper connector names! I've made a sincereattemp in this note to use the proper names at all times.- Many folks say you can test the deliver of fuel past the fuel filter(in the engine compartment) by squeezing the hole while the engineis cranking to feel for fuel pressure. I can't tell. I recommendremoval of the fuel filter. It provides proof positive.- The factory shop manual goes into the engine control unit debugging.It was not needed in my case so I'm glad I skipped that part.- The hardest thing in the world was to find the locations of thevarious units; and to find out how to remove some of them. In thisnote, I take special care to describe both the name of the unit andthe precise location, for others to benefit.- Most folks recommend disconnecting the battery & removing it from thecar when working on the fuel tank. I didn't do this, but you should.

Here's some of the links she references that were broken in her thread

zerothread?id=454http://forums.nicoclub ... d?id=47728

A "fuller" tank will help, but putting this off, only increases your costs.

Good luck

[ceningolmo]

As you said, she walks through in good detail. And, it is actually a pretty small portion of the whole process that is dedicated to the replacement of the fuel pump. In fact, it almost sounds easy (cringe... don't want to jinx it) based on the description.

I just want to make sure there isn't a parts list that isn't mentioned in that post. But, it sounds like if I talk to Joe at Scottsdale he will be able to hook me up with the pump and the o-ring.

Thanks for the help.

[elwesso]

Did you not believe me when I said you just need the pump and the O ring?? really I wasnt kidding!!

Just get in there and start ripping stuff apart....

[ceningolmo]

Well... I guess I was thinking that everyone was saying that because they are the only major parts that I would need. But, I didn't want to get in there and find out that I also need a doomaflingy washer in order to complete the job.

I would end up posting my dismay on the board... "I am replacing my fuel pump, but there is this doomaflingy washer I don't have...."

And everyone would be like..."why didn't know order it with the fuel pump? Duh, everyone knows you need the doomaflingy washer. You're an idiot!"

So... I guess I am just being careful. I am annoyingly thorough.

[Jeff Williams]

Ross, we are a lot alike, you and I. I printed Tangalora's post and bought a pump from Joe. The hum was annoying me for a few weeks, and was probably slowly getting louder for months. It is corrosion on the pump that causes it.

The hardest part for me was removing the rear brake light. It kinda pops forward and lifts out. I spent 10 minutes pulling and twisting on the stupid thing. Also, I pushed the pins that hold the rear deck, up from inside the trunk, rather than prying them from the top. Removing the gas cap is also a good idea, to help reduce the pressure.

Take your time, and make sure the new pump is completely in the frame and all the little plastic and rubber doomahitchys are reinstalled. Take your time inserting the pump and level float, so you dont bend or break the fuel sending unit float.

It took me about 2 hours to do the work. I spent some time cleaning up the leather and picking up all the trash under the rear seat.

It really is an easy procedure. Much easier than changing belts or spark plugs.

[Q451990]

And everyone would be like..."why didn't know order it with the fuel pump? Duh, everyone knows you need the doomaflingy washer. You're an idiot!"

And Brian would post... "if you did a search"

Heath

[elwesso]

i actually found about $5 in coins under my seats...

[Rex]

Yep, just the pump and O ring.

Do yourself a favor and run the tank down pretty low before starting and make sure you release the gas pressure (remove gas cap) after trying to run the lines dry (try starting with fuek pump fuse out). Round up lots of big towels to help soak up/catch any gas as you lift the pump out.

[ceningolmo]

Jeff,

Thanks for the help! A little reassurance from someone else who is "learning as he goes" makes the job sound a little more reasonable.

Of coure Wes thinks the job is easy. And, has told me so. But then, he spent his weekend tearing my engine apart as a favor... so, his mechanical inclination is somewhat greater than mine.

[elwesso]

you know really if you wanted, we could do the guides and fuel pump at the same time.....

[ceningolmo]

I am not sure if I have all the loot I need to order the fuel pump yet. I think I need another $50 or so... if I can get it in time, I will bring it with me. Even I just worked on the fuel pump while you worked on the guides... that way I would have you around when I had questions.

But, if I can't get the pump in time, I will handle it on my own.

[redmanfx]

It's great to see your enthusiasm and it's a breath of fresh air. I think that most here would encourage you to get your Q back to OEM, they just don't post and tell you so. It's also important to pace yourself because you'll find it's a passion thing that likes your wallet for a while. I call this car a hidden gen and it really is. You keep it up and you will love your car enough to go even further and get a body kit and 17' or 18' wheels etc, etc......

My car started out needing help I didn't even know it needed and now it's almost ready to show off it's progression and it's all owed to NICO. You keep it up and NICO will be here all along the way. But please make sure you spell correctly though or the spelling guy will tag you or tell you to search. See one big happy family!

red

[maxnix]

i actually found about $5 in coins under my seats...

All I found was a lot of dog hair from previous owner's mutts. Thankfully they rode on blankets.

But it does afford one an excellent opportunity to detail the rear seat and recondition with Lexol.

Tangalora's threads were meant to be stickies, so what happened?

[Rex]

All I found was a lot of dog hair from previous owner's mutts. Thankfully they rode on blankets.

But it does afford one an excellent opportunity to detail the rear seat and recondition with Lexol.

Tangalora's threads were meant to be stickies, so what happened?

As an interim step to them becoming full fledged articles (allowing for better search hits), I simply compiled a thread with about 8 or 10 of hers and then added key words to allow for easier results from internal-forum searching.

He's got the one she put together, but it's sans pics .

[Jesda]

http://www.q45.org/techhelp.html

^^-- Put together to avoid the nuisance of ZeroForums' crummy search tool.

[ceningolmo]

I have been doing most of my research of the articles/threads listed on q45.org. The search tool for the forum doesn't do a great job letting me sort through all the stuff... I have found it easier to just look it up on the q45 site.

Thanks for the point in the right direction.