Write-Up: Fuel Pump/Tank Sending Unit Replacement

does replacing the fuel pump require actually dropping the tank on these cars?
I did a search and couldnt find an answer here. I thought we had a write up on it. I just figured it would be the hard way on our cars, like everything else (belts,etc.).

its still a pain...but not as bad, pull out your trunk liner,you'll find an access cover. beware,you will probably have to replace the retainer ring, and be sure to blow off any dirt before extracting anything.

are you just changing the pump or the sending unit and all?

robertwolf86 wrote:

are you just changing the pump or the sending unit and all?

in theory it will be the pump. But on intense website they have a writeup for changing out the pump and it removes the entire sending unit. Im not sure if our cars are like that though. It was based on a w-body.

I just replaced my fuel pump a couple weeks ago. You will have to remove the bucket and sending unit. I replaced my pump with a Racetronix fuel pump but it was designed for the W body (most aftermarket fuel pumps that Intense or ZZP sells are for the W body). There are some differences. One most notibly is a second line (venturi line) on the top. I had to get a bucket from a 1998-2000 GTP and swap some parts around. If you don't use the GTP bucket, you might not be able to use the last 4-5 gal in the tank. If you don't use OEM replacement I'll give you the number of a guy that walked me through step by step.

if your swapping the pump for more fuel...funny thing is the factory riv pump is what the GN guys use as an upgrade,and the guy i used to work with at Malletts use them in the v8 solstice swaps...

ewolfe0050 wrote:

I just replaced my fuel pump a couple weeks ago. You will have to remove the bucket and sending unit. I replaced my pump with a Racetronix fuel pump but it was designed for the W body (most aftermarket fuel pumps that Intense or ZZP sells are for the W body). There are some differences. One most notibly is a second line (venturi line) on the top. I had to get a bucket from a 1998-2000 GTP and swap some parts around. If you don't use the GTP bucket, you might not be able to use the last 4-5 gal in the tank. If you don't use OEM replacement I'll give you the number of a guy that walked me through step by step.

ok, this is what I was thinking, that I might need to swap some parts out to make a the w-body part fit, kinda like I had to do with the headers (GTP tranny stick).

TType_Riviera wrote:

if your swapping the pump for more fuel...funny thing is the factory riv pump is what the GN guys use as an upgrade,and the guy i used to work with at Malletts use them in the v8 solstice swaps...

The upgraded fuel pumps are cheaper than a stock riv one right? I wont be doing this until I get to the point that the injectors are static, or if the pump decides to take a dive one day before I get to that point. Im not gonna do it until I absolutely have to.

I think I spent $250 for the pump, and a HD wiring harness plus the GTP unit (fuel pump, sending unit, and bucket) from a junk yard. It also included installation (I helped on install as well).

Has anyone had to replace their fuel pump? how long do they usually last and if not when should i expect i should have to replace it? its working fine but its got 160k miles on it and im pretty sure i got the one that came from the factory in the car.

I'm still running my factory pump at 135K . No worries. If it ain't broke don't fix it.

Yes, many people here have had to replace their pump. It's not a bad job. There's an access hole in the trunk floor.

Dont fix it unless its broke. If it isn't whining and your fuel level sensor works, don't worry about it.

If you have money, go to gmpartsdirect or another discount place and order another OEM pump. VERY easy to change, but DON'T do it with a full tank of gas like I did! My locking ring was completely rusted and had to be pryed out. I had to order it but the local dealer had it in stock. Fairly straight forward and simple install.

Like I said, don't fix unless its broke. Mine had 185k on it but the sending unit was bad. I accidentally broke a return line so I replaced it with an O'reilly unit for $306 or so. I would spend the extra $30 or so on an OEM unit if your not in a rush.

i still havent replaced mine. I heard the stock pumps were good for at least 300 WHP. Im probably close to that now if not slightly over.

My car has 191,000 and sure it hasnt been messed with. Car runs like new with exception of the new supercharger on it. You will find that these Buicks will have more wiring problems then anything because of the MILES of wires in them. [/img]

dreww wrote:

does replacing the fuel pump require actually dropping the tank on these cars?
I did a search and couldnt find an answer here. I thought we had a write up on it. I just figured it would be the hard way on our cars, like everything else (belts,etc.).

Yes, you do.. I just had to replace the fuel pump in my friend's 97 S/C and it is located in the gas tank. It is a HUGE pain! But, after its done, it is well worth it.

dscott2000 wrote:

dreww wrote:

does replacing the fuel pump require actually dropping the tank on these cars?
I did a search and couldnt find an answer here. I thought we had a write up on it. I just figured it would be the hard way on our cars, like everything else (belts,etc.).

Yes, you do.. I just had to replace the fuel pump in my friend's 97 S/C and it is located in the gas tank. It is a HUGE pain! But, after its done, it is well worth it.

dscott2000, There is an access panel in the trunk that allows for easy removal of pump without dropping the fuel tank.

Rickw wrote:

dscott2000 wrote:

dreww wrote:

does replacing the fuel pump require actually dropping the tank on these cars?
I did a search and couldnt find an answer here. I thought we had a write up on it. I just figured it would be the hard way on our cars, like everything else (belts,etc.).

Yes, you do.. I just had to replace the fuel pump in my friend's 97 S/C and it is located in the gas tank. It is a HUGE pain! But, after its done, it is well worth it.

dscott2000, There is an access panel in the trunk that allows for easy removal of pump without dropping the fuel tank.

I guess I owe someone an apology.. I didnt even look for the access panel. I just dropped the tank. I didnt think for a second that GM put in the access panels in. Sorry for the confusion.

The 1998/1999 fuel tank sending unit is a different part number than the 1997 but the wiring schematic shows it to be functionally the same. So I took a chance and ordered a '98/99 unit from ebay since it was too cheap to pass up. I ordered from this guy: http://stores.ebay.ca/evalero1 and I figure I saved over $100 on the parts. The job itself took about an hour and a half, there was a lot of corrosion on the ring holding the pump assembly in the fuel tank so I also cleaned that up at the same time.

Here's the original unit. Once I pulled it out, I could see the contacts were worn right off the rheostat. You probably can't tell in this crappy phone picture though.


The difference in the two units was the wiring harness, the actual rheostat modules looked to be pretty much the same:


All I had to do was to de-pin the old and the new sending units, and re-pin the new one into the old harness. Just insert a very small jeweller's screwdriver or piece of stiff wire in the notch above or below the purple wires and pull the wire out of the connector.


You should probably change the sock on the fuel pump while it's out but I was irritated after laying in the trunk so I skipped it. I tested it out of the tank before I re-installed. If you do this remember that the gauge will move very slowly, regardless of how fast you move the float. It will actually take a minute or two to go from empty to full. Check for fuel leaks before you re-install the access panel.

What is a resonable price to install fuel pump for a 96 s/c. Taking it in to be replaced and dont want to get hosed. Just a round about estimate. I'm not sure if my model car carries just the fuel pump, or if it has that whole pump sytem that needs replaced. Apreciate your time if you can help out. Thanks

You are having it done somewhere? I'd guess around $400.

does anyone know if the 96 has the easy access panel for the fuel pump in the trunk?

Yep, it does.

It's pretty simple to change, but the rusted o ring can be a pain to get off.

I still need to take mine back out and put it back together again as I'm getting an odor of gas in the car.

I had mine replaced and the shop decided to reuse the old rubber gasket rather than the one supplier because it looked so much different. Bad mistake as it leaked when filled up.

Would it be possible for anyone who knows where this access panel is, to take a picture of it?

It might not be for a week or two but I'll be swapping a pump and sender so I can take a few pics when I do it.