Given the age of our vehicles, fuel pump failure is both common and expected. The actual job of replacing the pump is fairly easy, given the right supplies and preparation.

Disclaimer: I offer this only as a guide showing the steps I used to replace the fuel pump. As always, use caution and common sense when working on your vehicle! I am not responsible for issues that may arise in your following of this guide!

That aside, I will gladly answer any questions you may have, and try help with any problems you may encounter.

You may notice discrepencies in the pictures, as they were not necesarily taken in order. The steps i describe however, will be accurate.

Required Supplies:

• Fuel Pump
• Fuel Strainer (sock)

Recommended Supplies:

• Fuel filler neck hose:

http://tinyurl.com/jpxl4

• Replacement tank straps & bolts:

http://tinyurl.com/jae6k

• Replacement Fuel Filter:

http://tinyurl.com/l2pvm

• New 5/16 Fuel, non-injection hose, 36" is enough. Less on 84

Process:

1. Relieve Fuel Pressure:

• Remove the Fuel Pump fuse and start the car. Allow it to stall, repeat until the car will not start, then turn the engine over for 3 seconds.

2. Disconnect the Battery
3. Raise the Car: You can raise only the rear and do this job, however i found it easier to raise the whole car.

• Jack up the front of the car, use jacks or ramps to support it.

• Jack up the rear of the car and place jackstands under the cradle. Important: Keep in mind that as you jack up the car the jack will try to pull it torwards you, make sure that the jack rolls forward and the car doesn't roll back!
  
  
  
• Shake the car by hand to ensure that it is steady on the stands/ramps

4. Dropping the Fuel Tank:

• Disconnect The fuel pump in the Engine Bay, and push the wires down torwards the tank:

84 Pontiac Fiero, Two connections, one two wire and one single wire:


Later Model Fieros, One 3 Wire Connector, Looking Down by the right decklid hinge:

• Remove the large Center plate, held in with 4 short bolts.

• Place a jack under the tank, slightly torwards the rear. You may want to place a block of wood between the tank and jack. Note the position of the jack relative to the rear tank strap.

• Remove the nuts holding the straps, if you have not done this before expect the nuts to be stuck. For this reason i highly recommend buying the replacement bolts.

• Bend the straps down out of the way.

• Lower the tank slightly and push it torwards the front of the car. You may have to gently pry it out.

• Disconnect the two large hoses:

• 84 Fiero: Slide the tank farther forward and disconnect The following three hoses:

• Later Fieros: Slide the tank farther forward and disconnect the following two hoses:

• Still with the later model, looking down from above the engine bay, reach down and disconnect the following hose, just below the pump connector:

• Begin to lower the tank using the jack, watching to make sure any hoses/electrical lines do not get caught as you let it down.

• At this point make sure the tank, and all related hoses and wires are completely free of the vehicle. You should be able to hold the tank with one hand, and pull the jack out with the other.

5. Removing/Replacing The Fuel Pump

• Remove the locking mechanism on the pump assembly by rotating it counter-clockwise. Do not use a screwdriver or other metal object that may spark! A brass punch works well, or if unavailable, a piece of wood.
  
  
  
• Carefully remove the fuel pump/sender assembly. It is easy to damage the sender unit. This is what it looks like outside the tank:

• Disconnect the plug from the top of the pump, behind the sender assembly.

• Remove the strainer(sock) from the bottom of the pump, it is held in place only by metal barbs.

• You should be able to pull the pump up, then out of the assembly.
• Install the new pump into the assembly, and reconnect the plug.
• Install the strainer on the bottom of the pump, it just pushes on. Ensure that it will not interfere with the movement of the fuel level float.
• Reinstall the assembly in the tank using a new gasket.
• If you are replacing the hoses now is a good time to install them on the sending unit. Remember: The large outlet is the high pressure line and requires two hose clamps! Leave plenty of extra hoseso you can trim it when you reinstall it!

On the left is the 84 unit and on the right is the 88.




6. Reinstalling the Tank

• Slide the tank back under the car and prop it up on top of a jack, raising the end with the hose connections close to its final location, but leaving room to work on the hoses.

88 Fiero V6, the small hose up top is the vent hose that runs back to the engine bay:

• Raise the tank up so you can reconnect the two large hoses. I suggest raising the tank just short of being fully in, so you can pull on the tank to help seat the hoses.

• Raise the tank fully into position. You may need to use some force to get it past the heating/ac line brackets. Reattach the two metal straps.

• Reinstall the Center bracket. Once the tank is secured by the two straps remove the jack and reinstall the center bracket. You may wish to use sealant on the bolts.

• If you had the long vent hose into the engine bay connect it now.

• Reconnect the fuel pump wires.

84:


88:




7. Testing

• Reconnect the battery.
• Turn to key to run. You should hear the fuel pump kick in for 2 seconds,  if not check the fuse under the dash, and the connections in the engine bay. If they are good your relay may have failed. You can test the pump independently of the relay using the ALDL terminal in the center console. If it doesn't run then, you may have forgotton to connect the wires to the fuel pump itself.
• Look under the car to ensure no fuel is coming out, you should not smell fuel.
• Start the car!
• http://youtube.com/watch?v=aJnXTphNVUM

  Great post Xanth,
I did the test on the connector (top right)  next to the cigarette lighter and found that the fuel pump still came on. Would it still be good and where is the relay? I got under the steering wheel to check the fuel pump fuse/ relay but couldn't find anything. Any idea?
Also to update you on the Clutch, I replaced the (2) slave Cyl and and still only got 1/2 inch in rod travel. I'm focusing on the master next, it's got a dark cloudy residue at the bottom of the resivoir. I rebuilt it once before but now it's back. I also got the steel peddle so. I'm pretty sure it's the Master cyl.
Thanks
David

I would like to offer a special thanks to "Xanth"  for the easy to follow tips on changing out the fuel pump on my 84 Fiero !!!
That job could of become a nightmare if some 'hack' had of gone underneath and started ripping things apart to get to the fuel pump!!!
It was a tough, messy job, but the pictures and the description sure made a tough job a lot easier to follow !!!

One additional question on testing the fuel pump from the ALDL terminal though ...
How do you do it ??
I've seen mentioned that  you apply 12 V to the 'G' terminal to check the pump ?
Is that correct ?
Which one is the 'G' terminal ?

I have no doubt that it needed the fuel pump, and some repairs to the gas tank from sitting for a number of years ... but I do wonder if someone could explain the correct way to check the operation of the fuel pump using the ALDL terminal ... is it 'G' ?

 
Lately, I've been trying to trace down a fuel problem in my 87GT. I have replaced the filter and the relay so I have pretty much narrowed it down to the fuel pump. However, I wanted to test it using the ALDL Block just for reassurance before tackling the task of replacing the pump. I used the orange wire from the cig lighter and plugged a power wire from it into the terminal "G" (top right terminal if you are facing the back of the car.) When I plug the power into the terminal, the fuel pump does not kick on. However, something really odd happens. It makes my floor board lights come on. This is odd to me b/c my floor board lights have not worked since I have owned the car (about 2 years.) Are these lights linked in any way to terminal "G"? I'm not real experienced in the electrical systems of these cars so any help would be greatly appreciated.