As part of a bulk buy purchase, I bought a Walbro in-tank replacement fuel pump. This particular pump is a 190lph unit (GSS-250) and requires the installation kit (430-730). The installation kit consists of the screen filter, length of fuel line, clamps, o-ring, and isolator. That part number is good for 2G Probes/MX-6s only. There are 190lph and 255lph pumps available for the 1G Probes/MX-6s (2WS only on the latter).

The beauty of this pump is that it is a direct drop-in replacement for the OEM pump. However, being an "in-tank" pump means that you have to get into the tank to replace it. On 1G Probes, this is a simple "remove the back seat bottom and swap it out" process. On the 2G cars, Mazda/Ford in their infinite wisdom decided to do away with the rear seat access to the pump so the entire fuel tank must dropped for the install.

- 10mm, 14mm sockets
- Pliers
- Flathead screwdriver
- Hammer
- Razor (to cut fuel line)
- Helper - not necessary, but a big help lowering/raising the tank

The first thing to do is to make certain there is little or no gas left in the tank. This will help during the removal/re-install of the fuel tank.

Raise and securely support the rear end of the car.

Bleed the pressure off the fuel system.

Disconnecting the negative battery cable wouldn't hurt either!

Under the car, the first thing I did was to disconnect the supply and return lines from the front, driver's-side location of the tank. Grab those pliers, compress the clamps and pull them back. Then either using your hand, the pliers, or a screwdriver, pry/pull the hoses off of the metal lines.

There may be some residual fuel in these lines. Have a rag handy to catch any that may come out.

Next thing to do is to get under the rear of the car and begin disconnecting the hoses and electrical connections. First disconnect the overflow hose from the overflow tube (ends above crossmember--red line points to it). Next undo the clamp (Philips head or 10mm) that holds the rubber filler hose to the metal filler neck.

Over towards the center (further right and forward in the photo) there is an electrical connector that needs to be separated as well as one small diameter line (vent?).

It is now time to begin removing the straps that hold the tank up. You will notice there are three straps, but the second and third both bolt to the same location. I began with the middle (angled) strap. Unbolt the 14mm bolt that attaches it at the back of the tank. Once that is off, the back end of the strap simply slides off the bracket it is on.

It is at this time that I recommend removing the (3) 10mm nuts holding the exhaust heat shield to the fuel tank cover. If you do not removed these, you will not get the tank down.

The next one I suggest removing is the far right strap (where the middle one was attached). Once the 14mm bolt is out, you can hang that strap on a bracket directly in front of it (see photo).

This way, once the final strap is loosened, it is ready to come down, but you still have something holding the tank up.

Unbolt the final strap. The tank shouldn't fall down, but be ready in case it does! Since the back end of the tank hangs over the rear suspension, the front of the tank must come down first. This is where it gets a little tricky since the front end of the straps are still attached to the floor pan. To remove the straps, they need to be pushed UP and then BACK (towards rear of the car).

See the photo: The end of the strap has a rod sticking out either side it. The rods fit through the top of that hanger and then the entire thing slides down and rests inside it.

Once the straps are slide up and out, the tank will come down. You more or less need to be under the tank when removing the straps so you can hold it up. With my Low Fuel light on, the tank could not weigh more than 30 pounds (it's all plastic). Once the straps were removed and the tank came down, I let it lay on my chest until the my trusty "helper" Dave completely removed the straps (remember the right one is still hanging on the bracket). I suppose that a jack could be used instead of your body (my original plan), but I would then suggest that you place a good size of plywood (at least 12"x12") between the tank and jack so the weight is distributed over more of an area and the chances of puncture/bending are reduced.

After the straps are out, I wiggled out from under the tank and let it lay on the ground. At that point, there was one more thin line left to disconnect. Take it off and slide the tank out.

Now it's time to remove the pump assembly from the tank. Locate the pump housing on the tank and look at the locking ring that holds it down to see how it works. To remove it, you will need a flathead screwdriver and a hammer. Place the end of the screwdriver against a tab on the ring and proceed to tap it loose (counter-clockwise).

Once the ring is off, unsnap the lines running from it that are connected to the tank at the two yellow holders.

Take your time getting the assembly out of the tank. There is a large screen filter as well as the fuel level sending unit which all needs to come out of a rather tight opening in one shot. Do not force it, just play with it until it comes out. NOTE: there is an o-ring seal around the opening on the tank. Make certain not to drop this in the tank during/after pump assembly removal!

Once out follow the instructions provided with the pump. Very straight forward, a basic swap and should take all of 5 minutes to do. You will need to trim the supplied fuel hose to the correct length. This is a photo of the Walbro unit mounted in the OEM assembly....a perfect fit!

Make certain to use the new o-ring to replace the old one that was on the tank. Putting a little 3-in-1 or WD40 on the top of it will ease the installation of the locking ring. Place the o-ring around the opening on the tank. Re-install the pump assembly. Again, take your time!

Once the assembly is in, ensure that the o-ring is still properly seated and that the pump housing is in the correct orientation (a good way to do this is to snap the lines back on to the tank). Re-install the locking ring: make certain that all tabs on the ring go under the tabs on the tank. In the same manner as its removal, tap clockwise with a hammer and screwdriver until the tabs are safely under the tank tabs. Make sure that the o-ring has not bunched up. Proceed to tap the ring clockwise until fully seated against the stops.

Slide the tank under the car and re-install in the opposite of it's removal.

You now have sufficient fuel volume and pressure for safer NOS or boost applications! Enjoy!

This site is made possible by Geocities.