1999 Buick Regal Fuel Level Sensor Replacement and Fuel Pump replacement.


[This repair may apply to the following vehicles. 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 Buick Regal, Buick Century, Pontiac Bonneville, Pontiac Grand Prix, Chevrolet Lumina, Chevrolet Impala, Chevrolet Malibu and other similar cars.]

Update 1-4-2011

Scroll to the end of this article for information on replacing the whole fuel pump. 3 months after I replaced the sensor, the pump died.

Posted 7-12-2010

My fuel gauge went crazy about 6 months ago. My gauge read full or nearly full all of the time. I've been using my trip odometer to keep track of the fuel. I can always get 300 miles out of a tank. But what a hassle if I accidentally reset the trip odometer. I decided to fix it.

Before you start

This was a hard repair. It didn't seem like it would be but I made some mistakes and ended up doing it twice. I ended up with my neck in knots for a few days. You have to do the whole repair in the back seat of the car working through the trunk pass-thru. Since every repair I do is a learning experience it took a long time. If I had to guess I'd say it took about 6-7 hours total to do this. That includes doing it twice. Seems like it should take an hour. I could probably do it in an hour now. Maybe with these instructions you can too.

What you'll need

-New fuel level sensor
-New fuel pump tank gasket (a must. A real AC Delco part may come with one. If not, buy one, really.)
-Standard screwdrivers
-Towels to get the pump out of car
-Paint can key (helps)

Don't Forget!

Your working around an open fuel tank. No sparks, no flames, and you'll need good ventilation. You can't get careless. The fumes really pour out of the tank when the pump is out. I kept the trunk open and put a box fan in the front seat blowing toward the back seat to keep the fumes from building up in the car. BE SAFE or DON'T TRY THIS.

Relieve the Pressure

The fuel system is always under pressure. The fuel lines are under pressure all the way to the gas tank. If you pull the hoses off the pump without relieving the pressure you'll end up with fuel squirting all over the inside of your car.

My simple way of releasing the pressure is to pull the relay for the fuel pump while the car is running. This is different than the fuse panel you find inside your car near the glove box. (I know because I looked at my inside fuse panel before I remembered the other panel.) If there isn't a diagram for the engine fuse panel printed on the box, look in the owner's manual. You may have a fuse or a relay block. I keep saying fuse but I think the block I pulled is actually a relay.

While the engine is running, open the fuse panel in the engine bay of the car. Pull the fuel pump relay. It took a pretty firm tug to get this out. The car ran for 2 or 3 seconds and died. Pressure lowered. In the picture below, relay #19 has already been pulled. It was between the 2 lower gray blocks. If you look in the picture above you can see the relay sitting on the right side of the cover. It's pretty dark. Turn the ignition off. I'd leave the fuel pump relay out until you're ready to test the pump.

Open'er up.

In my car I can see the fuel pump access cover through the pass-thru in the back seat.

You find this access cover in the trunk. You have to pull up the carpet pad to get to trunk liner.

My car has a 2 piece liner which splits right over the access panel. Remove 7 nuts to get this open.


IMPORTANT. Once you open the panel - grab a ShopVac and VACUUM. You don't want any debris getting into the tank and fouling the pump. Grab a good strong vacuum cleaner and brush. Brush the top of the fuel pump to loosen dirt and debris. Get the vacuum in there and suck it up. Get it as clean as you can. Mine had lots of rust around it.

See how much cleaner it is?

Detach the 3 rubber lines from pump. You need to squeeze the clips at the top of the rubber hoses to release. The hoses are very stiff and hard to move. They will move.

The pump is held in by a single spring steel 'C'-ring tucked under 6 tabs. With a pair of pliers squeeze the holes in the C-ring together. It will make sense when you see it. Once the ring is released the top of the pump might spring out of the hole. If it doesn't, pry the lip of the pump up with a standard screwdriver or paint key.

The pump is up. You need to rock it to the right to get the fuel pickup and float up and out. I wondered why the spring loaded top? This pump is probably used in lots of GM cars. The pump can scale to fit tanks of different heights. Pretty smart.


Side view of pump

Close up of the bad fuel level sender. See the black arc with the light line through it? The small brushes have worn all the way through the contacts. That's why the fuel gauge is going crazy as the tank heads toward empty. Right now the sender is in the FULL TANK position. At about half a tank the brushes lose contact with the sender.

Close up of the electrical connections from the sender.

Lower electrical connections.

Fuel pickup. I thought this was fascinating. It's like a tea bag wrapped around a plastic lattice. The lattice keeps the bag open. It would take a lot of debris to completely plug the pickup. Mine was free of any obstruction. The yellow float is on the left.

Here is the new fuel level sender I bought for $20 on ebay. Looks like the right part, but it isn't. I manage to make it work. Read on.

The parts look similar but they aren't exactly the same. The clip at the top of the new sender isn't exactly the same shape.

To put the new sender in I have to remove the old sender's electrical connections. Use the blade of a standard screwdriver to press the clip down and remove the plug.

New plug on the left (red cross bar) and old plug on the right. They match.

Second sender connector. Original plug on left. New plug on right. They don't match. Ugh.

The internal clips are different as well. Now what do I do? Original clip on the left has the same gauge black and white wires coming out of the back as the new plug does.

I used a small screwdriver and pushed the contact clips out of the plug (the red plastic cross bar was already removed when I took the picture below). I did the same thing with my original plug. I swapped the plugs and put the original in the new connector. I failed to take pictures when I did this. I only took this one. I should have documented the swap better. If you run into this problem, know that this worked for me.

Here's another problem. This is a profile shot of the new sender in white plastic and the older sender behind it. Look at the old sender's clip. It is about 1/8th of an inch higher. You can see the new white sender's clip won't reach the open box receiver on top. What did I do? Force it. Did it work? Well yes, sort of. One of the clip arms broke off. But I was able to get the sender into the same position. I clipped it in. Seems like it will hold.

Here is the new sender in place with all the electrical connectors in place.

Before I install the fuel pump I want to test the sender. I plugged in the electrical connection to the pump only. There is another black plug which plugs into an emission control device. I think this emission control device detects positive air pressure in the fuel tank. It's probably the bugger which can tell when your fuel cap is loose. Back to the test... I turned on the ignition. The fuel pump relay has not been plugged in. I figured the sender is active even if the fuel pump is off. I was right.

I moved float by hand and watched the gauge. I moved the float quickly to the tank empty position. The gauge moves much more slowly than the sender position would suggest. I think the instrument panel needle moves slowly so it isn't constantly wiggling as the fuel splashes around in the tank.


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Here comes trouble

So everything looks good, or so I thought. The sender works properly. What I didn't know is the new sender is much tighter than the old sender. It takes more effort to change the new senders position. So when I put it in the tank, the tank always read FULL. I burned about 3/4 of tank of gas and it read just under full. The float wasn't touching the fuel. The sender arm would only fall when I hit a big and I mean big bump in the road.

One more problem. A big fuel leak! I filled the tank at the gas station. Instead of the pump stopping I heard gasoline splashing on the ground. Fuel was pouring out from around the fuel pump. The rubber gasket didn't seat properly I figured. I had to take everything apart.

First thing I did was buy a new spring metal C-ring. Mine was old and rusted. I also bought a new fuel tank gasket. I paid about $23 for both at a GM dealership in Farmington Hills, MI.



Good thing I did buy a new gasket. From all the pushing and forcing, I had ripped the old gasket.


Here's my fix for the stiff sender. I took 12-guage copper ground from a piece of ROMEX and wound it around the sender arm. I didn't want to use anything with a bolt or fastener which could fall apart over time. This did the trick. So before you put the pump back in, do a simple test and make sure the sender arm falls freely. Common sense, but I didn't check that the first time I did it. I also tested this setup in a bucket of water to be sure the float could hold up the extra weight.


Here is my trick for holding the pump down as I slid the C-ring in place. I use a screwdriver and a paint can key to get under the tabs. This is the hardest part of the whole job. It is such a tight fit and you're doing all this while reaching through the back seat of the car. You can do it, but it isn't fun. Maybe your car will be easier than mine.

After it was back together I went to gas station and filled it to the top. No leaks. It's been working fine since May 2010.


So this is end of the story right?

No. I wish it was. About 4 months after I replaced the sensor the whole fuel pump died. It died with a whimper, not a bang. This car gets driven to work everyday. I parked it for a week when I went on vacation. When I came back, the car wouldn't start. There was absolutely no warning. The pump never ran again. I guess after 170,000 miles I should have replaced the whole thing. As you can see, I'm no expert, I'm just persistent.

Read this before you buy a fuel pump.

I started shopping for fuel pumps. From the dealer they list for about $450. I was breaking the guy's heart at the GM dealership parts counter and he offered it to me for $325. Still too much. (You can haggle at a dealership.) I looked at O'Reilly and Advance Auto. They were selling an Airtex fuel pump for about $250. Again, too expensive. Beware of the Airtex fuel pumps they sell. Look closely at the picture at O'Reilly or Advance. The Airtex pump most places sell is a universal fuel pump. They bundle it with an electrical connector. The plugs don't match the plugs on my pump. With the $250 Airtex pump I would have to cut my plug off and solder or crimp on a new connector and hope I got all the connections right. The access hole only gives you about 6" of exposed wire, tops. It would be an awful job on top of an already awful job to put another connector on that short wire. I'd buy OEM before I did that.

(1/27/15) A reader sent me and note and said "You may be interested to tell your readers to avoid the Evan Fisher pump on Amazon. It's dirt cheap.......for a reason." The reader had 3 of these pumps fail in a few short months.

I shopped on Ebay and found this pump sold by ABC Marts. It was about $90. Here's a picture of the listing. (This listing apparently long gone. It was there as of May 2010. Readers have told me they can't find this company any longer. I don't have any more info for you. In fact, I don't have the car any longer. My niece has it now. Still running on this pump.)

The picture was exactly what I was looking for. It had the same square grey connector my fuel pump had. If this picture was right this would be a perfect fit. I emailed the company and they assured me it was as pictured. I ordered it. ABC Marts was great. Good email communication and very friendly. They are based in Florida, I think. When I got I was thrilled. Everything was exactly as promised. Remember, you only get the pump assembly. No gasket or C-ring. You need to buy those things. As I said earlier both parts were $23. Here's a picture of the new pump, below. Beautiful right? New everything, perfect plugs, easy wiring, slips right in. Keep reading.

The new sender has the same problem! What?

The new fuel pump has the same problem my new fuel sender did. The float doesn't fall to the level of the gasoline. The sender is as tight as my other sender was. How did I figure this out? By installing it and driving around. Oh my gosh! I had to pull this thing out AGAIN! I was so stupid for not testing this. I just figured the new pump would be perfect. Stupid, stupid, stupid! After looking at the new sender I'm sure it's made by the same company.

The fix was simple. I simply put my copper weighted float arm on to this new fuel pump. Worked like a charm. It's been running fine for months.

Painful lessons with this project. Thank goodness I'm already bald, or I certainly would have been after all this work.

So what did I learn?

- If your car has over 100,000 miles and your fuel gauge is going wonky, replace the whole pump.

- The cheaper $90 pump works great. It's quiet and so far, reliable. Every bit as good as my original.

- Test, test, test the float before you put it in.


Good luck. -Mike