DW200 Miata Fuel Pump Replacement

As part of my kswap, I needed to upgrade my fuel pump. A Walbro 255 is the go-to pump for a lot of people, but it’s also fairly noisy. Instead, I went with a DeatschWerks DW200, and I can say that I can’t even hear it. Miata fuel pump replacement is the same for any Miata, though, and it’s also the same whether you’re upgrading or simply replacing a failed stock pump.

Depressurize Fuel Tank

Yellow plug at the top disables the fuel pump

You do want to depressurize the fuel system before doing this job, unless you enjoy being sprayed with gasoline. On a Miata, it’s very easy. Start the car, reach under the dash, and unplug this yellow plug. That will cut power to the fuel pump. Let the motor stall and stop. You also should disconnect the battery if you haven’t already.

If your car isn’t running, you can probably get away with simply opening the gas cap, but your mileage may vary.

Carpet Removal

All of these buttons

All of these tabs must be removed

Step 1 in Miata fuel pump replacement is actually getting to the pump. To start, remove all of these tabs from the carpet covering the package shelf. I use one of these cheap fastener removal tools. You will almost certainly break at least a few of these, since some of them are likely 20+ years old. I also went ahead and bought extra clips as well. One box will be more than you’ll ever use.

Carpet removed from package shelf

With all of the clips removed, the carpet should pull out easily.

Remove Shelf Cover

Covers the fuel tank and pump

I don’t know what this thing is called – fuel tank cover, I guess? Anyway, it needs to come out.

Undo the screws

Even more screws

This is pretty straightforward. Use a phillips head screwdriver and remove all of these screws.

Now you can see the fuel pump

Once that is done, the fuel pump is visible.

Loosen Your Rollbar (If Required)

Here’s what the rollbar blocking the pump looks like

If you have a rollbar, it may block the removal of the fuel pump, as shown. In my case, the harness bar is directly above the fuel pump. If this applies to you, here is a guide on loosening your roll bar.

Remove the Fuel Lines and Unplug

I used the channel locks to undo the hose clamps for both lines

Can also use to very gently twist the hose to get it loose

Again, depressurize the fuel tank before doing this. At a minimum, unscrew the gas cap. I use a set of channel lock pliers to grip and pull back the hose clamp. I also like to use them to very gently grip the hose and twist it. Rubber hoses like to stick to fittings like this, so twisting it helps break it loose enough to slide off.

Complete

Here are the fuel lines removed. The white plug also needs to be undone.

Surely anyone can do this

Obviously, you squeeze and pull the white plug. If you can’t figure that out, please get help with this job.

Remove the Old Fuel Pump

These phillips head screws hold the fuel pump to the tank

Once removed, the fuel pump assembly will lift out

Might have to finagle it a bit

You might have to finagle it a bit, but it will lift right out.

Removing Old Fuel Pump From Assembly

This is what comes in the DW200 kit

The DeatschWerks DW200 kit includes what is shown in the picture. We need to swap this stuff onto the fuel pump assembly we just pulled out of the car.

This is the main plug for the fuel pump

Oh good, there will be nothing bad under this heatshrink

Somebody did a fantastic job here

Need to snip this off anyway

So we need to splice the power wires for the pump to the new one. If yours is plug and play, good for you, but mine wasn’t. The old fuel pump plug doesn’t fit the DW200. When you go look, you may find a previous owner has done a fantastic job at this on a previous occasion. I honestly wonder if this was done with a lighter, but hey, it worked for at least 6+ years since I’ve had this car. At least they used heat shrink? I’ve never seen a soldering job that looked like a flux core weld before.

Anyway, snip off the old wiring but leave yourself as much slack as you can.

There are two hose clamps

I went ahead and undid both of them

These two hose clamps and this length of fuel line are connected to the fuel pump. I removed both of them, since the DW200 kit comes with a new length of fuel line to use.

Slide the strap thingy down

This is good enough

There’s this strap thingy that needs to be slid down. Again, no idea if it has a real name.

Final screw holding the fuel pump on

This is now all removed from the fuel pump assembly

Once that’s all done, there’s only one phillips head screw remaining. Undo it and all of these components come off.

Prepare the New Pump Wiring

Solder the new plug to the assembly

Preferably use an actual soldering iron

Solder the new plug onto the old assembly. Definitely use heat shrink to protect the connection. I heat shrinked each solder connection and then heat shrinked the two wires together. Use an actual soldering iron of some kind, rather than whatever the previous owner of my car did. A crimp could be better here, but I wasn’t sure if it would sufficiently seal the wire or if plastic insulation on cheap butt connectors would hold up in a gas tank. I opted to be safe rather than sorry and repeat what was already there before. Of course, red wire goes to red and black to black.

Connections get heat shrink separately

May not be necessary, but I also heat shrinked both wires together

Plug reinstalled on assembly

And here’s the final wiring job. Of course, it should plug right back in to the assembly. If it doesn’t, I’m concerned for you.

Fuel Line on New Pump

Fuel line, clamps, and new pump

Remove smaller rubber cap and install fuel line and one clamp

I went ahead and put the short length of new fuel line on the pump. One clamp can go on now, the other needs to wait of course.

Sock on New Pump

Save the metal piece from the old pump, chuck the old rubber piece

You need to keep this metal bracket from the old pump. You can chuck the black rubber piece, the new pump comes with a fresh one. This is used to hold the filter sock on the fuel pump.

The pump and the brand new sock

Goes on this fitting

The sock goes on the pump and prevents it from sucking up any debris in the tank. Install it as shown, with the small hole going over the matching spot on the fuel pump.

Sock on, ready for bracket

Rubber piece goes on over it as shown

The sock is installed

Put on Sleeve Thingy

Sleeve and strap thingy need to be reused

They pull off

The sleeve and strap thingies need to be pulled off of the old fuel pump to be reused.

Turn it inside out to more easily install it

Unroll it onto the pump

This piece can be annoying to get on to the pump. I had the most luck rolling it over and then unrolling it onto the pump.

Don’t forget the strap thingy

And last but not least, our friendly neighborhood strap thingy.

Install Pump on Assembly

Bolt the sock bracket or whatever this is with the phillips screw

Screw the bracket back on to the pump assembly as shown.

Reinstall the piece of fuel line

Reinstall the fuel line section. You may need to do this before or after the phillips screw above, depending on your luck. A little bit of silicone lubricant can help slide fuel line.

Plug in the plug, sort of looping it

Plug the wire into the fuel pump. I sort of looped it around the lines, because that’s what was done before. Then again, a horrible solder job was also done before, so maybe this is the blind leading the blind.

Reinstall

Assembly prepared and ready to reinstall

Drop the pump back into the tank

Now the whole thing is ready to drop back in. As they say in the Hayne’s Manual, “reinstallation is the reverse of removal.” I like to do the minimum first – screw the pump mounting bolts back in, reinstall the fuel lines, hook the white wire back up, and plug in the battery. At that point, test to make sure the fuel pump turns on and the car will fire up before putting the package shelf back together.

If you don’t have a roll bar, Miata fuel pump replacement is easier than most other cars, as you don’t have to drop the fuel tank. If you do have a roll bar… well, it’s probably still easier.