'91 K5 fuel pump replacement

[midnitewarya]

So, after only 278,550 miles, the fuel pump finally called it quits in my '91 K5. Any tips on replacing the whole unit? I'm not opposed to cutting through the floor, just need some measurements to make sure I only have to cut once.

Any advice would be great!

-Al

 

[Losthills78]

Dont go cheap on the pump.. Just put one in from autozone and its pretty much crap.. Ill be lucky to get a few more months out of it.. Its not to bad if u got the tools.. I didnt and had to lossen the bumper..

 

[496truck]

x2 on the cheap pump. The first one I put in was an Airtex, almost got a whole year out of it. The parts store warrantied it for me but I still had to replace it again. A little over a year on the 2nd one so far. If it goes I'll pony up for a better one.

Not hard to drop the tank depending on your rust situation. Don't need to remove it completely if you're good.
I just put a floor jack with some 2x4s under the tank.
Remove the 3 rear skid plate bolts.
Remove the 2 rear (actually 4 cause they're doubled up) tank strap nuts.
Undo the fuel filler neck.
Undo the ground strap.
Lower the tank to gain access to the fuel lines and undo them.
Lower the tank more and you can access the top of the tank to remove the pump/sender. At this point you can just pull the whole tank out if it's easier. But the key is to leave the front attachment points in so that the tank lowers and pivots down and out the back.

 

[4xcrazy]

ONLY "278K miles"???? worded like it didn't make it that long..

Honestly I'd be suprised if it hadn't been changed already, I havent seen them last much past the 150-170k miles range.

As mentioned, do not go cheap, stay away from Airtex, personally I would say go to Napa or somewhere and buy the factory replacement, like the Delphi unit.

Not gonna comment on the cutting of the floor, not my thing to do, I always drop them.

 

[wasted wages]

pull the carpet back,,,,, grab your cutting torch...


man..... In-tank fuel pumps bring the suk......

 

[rampage]

Honestly I'd be suprised if it hadn't been changed already, I havent seen them last much past the 150-170k miles range.

I'm the original owner and mine started making a horrible noise so I changed it out at 265K.

 

[63chevyll]

As mentioned, do not go cheap, stay away from Airtex, personally I would say go to Napa or somewhere and buy the factory replacement, like the Delphi unit.

Not gonna comment on the cutting of the floor, not my thing to do, I always drop them.

Airtex, Junk, and havent had much luck with the Bosch for domestic cars/trucks

the Deipli is good, or just call GM.

I had to do a sending unit onn my old 89K5 and ended up getting a pump and sending unit assy for $250 from GM, it was alot of $$ but my guage worked afterward and it had a new pump

 

[63chevyll]

an oh yeah.....Please dont cut the floor.

 

[midnitewarya]

ONLY "278K miles"???? worded like it didn't make it that long..

Honestly I'd be suprised if it hadn't been changed already, I havent seen them last much past the 150-170k miles range.

278K surprised me too, I've been "expecting" this for about 10 years now, lol. When it wouldn't crank I was saying in my head "FINALLY!".

It's the original unit, as I am the original owner and have never been back there. I've had the fuel system regularly serviced, if that was any help.

My biggest concern was having to drop the axle. With the 6" lift this sounds like it won't be such a hassle, and with my new air tools the wrenching doesn't bother me much anymore. I'll go from under!

Just to be sure it's the fuel pump, I pulled off the fuel filter. When you turn the ignition to "on" there is a little squirt of fuel out of the line, but when you turn it to "start" there is nothing at all coming out of the lines. I was a little worried it could be something else because when you turn it to "on" you can here a little bit of fuel trickling in the tank from the return line (I guess). My guess is the pump has just lost it ability to build up enough pressure to get the system running.

 

[rampage]

If you unplug the wire harness for the gas tank (the connector is located on the driver's side next to the frame rail just in front of the tank) the gray wire is the power to the pump and the purple wire is for the sending unit. If you connect a 12V supply to the gray wire and ground to any metal part, the pump will operate.

 

[diesel4me]

Someone cut the floor in my 85 Suburban diesel to either remove the stock pump in favor of an external one or who knows why??...it has an electric universal one mounted on the frame rail now,the retard who put it there mounted it on the outside of the rail,right next to the spring shackle,and the rubber hose they used runs the entire way to the fuel filter--it was rubbing on the shackle!.....

I suppose dropping that 40+ gallon tank IS a heavy duty chore,but most every vehicle I have seen that someone chopped a hole in the floor to get at the sending unit and pump,wasted their time (and their floor!),because its no picnic getting that locking ring off thru a peephole and putting it back on sucks even more--plus you cant access the wires and hose connections too well,and chances are good at least one of the metal lines in the sending unit will need repair too,which cannot be easily done with the tank still mounted..

Yes ,is does SUCK,it was a stupid idea IMO,to put fuel pumps IN the gas tank...but dropping the tank is the right way to do it,and you may discover the top of the tank is full of pitted areas that'll leak too,once its out..

My '95 Frod Contour actually has a big rubber "cork" under the back seat that supposedly allows you to remove & replace the electric fuel pump from inside the car,but one my friend replaced at his shop disclosed the hole isn't really big enough or centered right over the pump well enough to weasel it out of there--we ended up using tim snips to open it up bigger,and had to patch it back together afterwards...it was a nice thought Mr. Ford--but they didn't try removing a pump after they designed the floor that way evidently.....looked good on paper!!..

Why more vehicles dont have access doors or holes to get at in tank pumps like forigen cars often do baffles me..I gues car designers hate service techs??..