How to Replace a Fuel Pump

image of a fuel gauge in a car dash

So your car’s been experiencing bad fuel pump symptoms. Sounds like an expensive, time-consuming fix, right? A fuel pump replacement doesn’t have to be either of those things. With some care and attention to detail, anyone with fair mechanical proficiency and a set of hand tools can get the job done.

As with any project, be sure you have on hand all of the parts (be sure they’re the correct parts!) and tools you’ll need for the whole job. That goes double if the car you’ll be working on is your main form of transportation. If you get the tank out and realize you need another tool, you’ll be left looking for a ride.

Before you get started replacing the pump, be sure to check your tank for any leaks or other damage—since you’ll have the tank out anyway, it’ll be easy to replace the damaged fuel tank at the same time. Also check to see if your tank has a drain cock or drain plug on the bottom side of the tank. If it does, it’ll be easier to get the fuel inside the tank out.

As with most repairs or replacements on an automobile, the cost to replace a fuel pump is less if you do it yourself. So take your time, be patient, and be alert, and everything should go smoothly.

Difficulty

Intermediate: A beginner may want to steer clear of this one.

Estimated time needed

One to three hours, depending on skill level, tools available, and vehicle specifics.

What you’ll need for a fuel pump replacement


WARNING! First and foremost, remember that you’re dealing with gasoline—a highly flammable, dangerous substance. Don’t smoke while working on the fuel system and keep all sources of sparks or flame far away from the vehicle and fuel tank during the entire operation. Keep in mind that light bulbs can be very hot, so keep your incandescent shop light on the bench, and use LEDs if you need to work at night.

Also remember that static electricity from your clothes, the vehicle’s interior, or other sources can create a spark, and that spark could be deadly. When removing fuel from the tank, be sure to use a hand siphon pump. Don’t use an electric pump—there’s a risk of a spark causing an explosion.


Step-by-step guide:

  1. Disconnect the negative battery cable.
  2. With a safe workspace laid out, and your car parked on a level, firm surface, jack it up and place it on jack stands, or use a lift to provide access to the underside of the car.
  3. Relieve the fuel system pressure (How to do this varies between makes and models, so refer to the service manual for your specific vehicle).
  4. Disconnect the filler neck from the fuel tank per your service manual.
  5. Support the fuel tank with the jack and the block of wood.
  6. Remove the bolts from the straps holding the fuel tank in the vehicle.
  7. Carefully disconnect the wiring connections, fuel lines, and vent hoses on the top of the tank before fully lowering the tank.33556245572_298db82b8c_oSource | Flickr
  8. Once the connections are released, use the jack to carefully lower the tank out of the car.
  9. Clean the top of the tank around the existing fuel pump assembly to prevent any dirt or debris from falling into the tank during removal.
  10. Refer to your service manual for instructions on removing the fuel pump assembly from the tank. There’s typically a plate held in place with screws or bolts, which, once released, enables removal of the pump.
  11. Install the new pump in the opposite order you used to remove the old one.
  12. Reconnect the fuel lines, wiring connections, and vent tubes, and reinstall the fuel tank.
  13. Reconnect the fuel filler tube.
  14. Reconnect the negative battery cable.
  15. Fill the tank with gas and go for a drive to verify that you’ve properly replaced the fuel pump and that everything is in proper working order.

Got any tips on replacing a bad fuel pump that we didn’t cover? Share them in the comments.

Unlock Your Engine’s Hidden Horsepower

race car

Source/www.twin-loc.fr/Flickr

Many vehicle manufacturers are ultra conservative when it comes to programming engine control units (ECU), also known as the engine control module or the engine control computer at the factory. They’re not going to program the control module so that the vehicle runs at its maximum power capabilities, in part because they’re concerned with things like the vehicle warranty, emissions, and fuel economy. Their conservative settings, however, leave you with a vehicle that isn’t producing as much power as it could. How frustrating is that? Is there a DIY engine tuning solution? Quite a few, actually.

ECU unlocking software

A lot of you are probably thinking, “ECU chip tuner” or “reflash” right about now. Reprogramming the engine control computer seems to be the common wisdom when it comes to increasing horsepower. For the uninitiated, an ECU basically controls how the engine goes about its business of producing and delivering power, including air/fuel ratio, ignition timing, idle speed, valve timing, and RPMs.

Back in the day, if you wanted to do some car tuning and change the ECU’s parameters, you had to actually change computer chips, physically swapping them out with newer chips that had software featuring the performance parameters you wanted. Today, one can install new software that changes the ECU’s operating parameters simply by plugging into the OBDII port. Boom. A few keystrokes later and you just raised the rev limit, governed top speed, and tuned the air-to-fuel ratio.

Replacing an engine control computer

What about switching out the engine control computer entirely with a new one instead of just reprogramming it? Is a new control module an option? A couple people, including Ethan Campbell, a Roanoke, Virginia-based tuner toying with a ‘96 Miata, have mentioned the MegaSquirt PNP ECU (MSPNP2) as one possibility for completely replacing the stock engine control computer. Campbell’s winter project is taking an engine with a VVT head from a ’99 Miata and installing it into his ’96 and adding a MegaSquirt ECU. MegaSquirt describes the product as taking “over the functions the stock ECU provides, like fuel control, ignition control, and various other outputs, and lets you adjust these yourself by connecting a laptop to the MSPNP2.”

Acesstuner

Another car-tuning option to increase engine performance is Accesstuner from Cobb. The manufacturer describes the software as allowing “the user to get into the heart of the OEM ECU and create custom calibrations for vehicles equipped with virtually any performance modification. The end result is a tune that is custom tailored to the vehicle’s unique modifications, producing maximum power gains while maintaining the drive-ability and sophistication inherent in the OEM ECU.”

Turbocharging

What about turbocharging as a car-tuning option? I know that turbocharging a non-turbo car is a viable option for increasing horsepower, but it’s also one that’s accompanied by a whole host of other considerations, including boost level, compression ratios and avoiding knock, that have to be planned for to avoid engine damage when turbocharging. There’s even the option of adding a Nitrous Oxide System (NOS).

If you have DIY engine tuning solutions to share, leave us a comment.