1995 3000GT VR-4: MKIV Toyota Supra Fuel Pump Upgrade

These instructions apply to a 1995 Mitsubishi 3000GT VR-4, but are easily transferable to any year of turbocharged 3000GT or Dodge Stealth.



The Procedure

Remove RHS Cargo Tray and Spare Tire
 
  The cargo tray is held in by 3 Phillips Screws; remove it and the spare tire.

 

Remove Fuel Pump Access Panel
 
  The panel is held in by 4 screws - if they're stuck, try using the impact driver to loosen them.

 

Disconnect Fuel Pump Wiring Harness and Relieve Fuel Pressure
 
  Unplug the black wiring harness to the right rear of the fuel pump access hole. Now go try to start the car. Once it dies (or if it never starts), you have releived the presure from the fuel system. Keep in mind that there is still fuel in the lines, and it will drip out when you disconnect stuff. This step only serves to prevent fuel from spraying out when you disconnect stuff. Use appropriate caution when working with fuel!

 

Lubricate Fuel Line Fitting
 
  Technically, you'll need to loosen the lower fitting before you can completely disconnect this fitting. However, I've usually found this one to be the harder one to loosen. Just in case you can't get this one loose and have to drive the car somewhere to get some help, there's no point in loosening the lower one until you're sure you can get this one loose. Once you've soaked the fitting with penetrating oil, lightly tap it with a wrench to allow vibration to help the oil get into the threads of the joint. Let it sit for 5 minutes or so.

 

Loosen Upper Fuel Hose Fitting
 
  Put your 14mm flare nut wrench on the rearward side of the fitting and then put your 19mm open-ended wrench on the foreward facing side of the fitting. Keep in mind, that it's the hose-side of the fitting that will move, not the pump-side. If you position the wrenches as shown in the picture, you can simply wrap both of your hands around the wrenches and squeeze them together. Assuming you break the connection free, move on to the next step. If not, keep trying, or enlist the help of your muscle-bound neighbor. This is likely to be the hardest part of the whole process. You can do it. Also, you may want to stuff some paper towels under the fitting to catch any fuel that drips out.

 

Remove Lower Fuel Hose Fitting
 
  This connection is accessed from under the car. If you're a contortionist and know where the fitting is, you may be able to do this with the car on the ground. If you're a normal person, then you'll probably need to have the car up on a lift or jack stands at this point. Follow the same basic procedure as the upper fitting: soak it with penetrating oil, position the wrenches, and squeeze until it breaks loose. Completely disconnect this fitting once you get it loose. Be careful not to let the fuel from the line go everywhere, especially all over you.

 

Disconnect Upper Fuel Hose Connection and Remove Hose
 
  At this point, the hose is free to rotate, so you can go back to the upper connection and fully disconnect it. This completely disconnects the hose from the car, so remove it and put it in a safe place.

 

Unbolt Fuel Pump Housing
 
  There are a bunch of 8mm nuts around the perimeter of the fuel pump housing; remove them all.

 

Remove Fuel Pump Assembly From Car
 
  At this point, the fuel pump assembly is no longer connected to the car. You'll need to lift it straight up for about 1/2" to clear the mounting studs, and then you can rotate, tilt, and raise it to get the assembly out. It probably seems like it won't come out, but it will. You may need to move the fuel vapor return line out of the way - there's no need to disconnect it unless you really want to.

 

Examine and Drain Fuel Pump Assembly
 
  After you pull the assembly out of the car, it will probably drip for a while, so it'd be good to have a bucket handy to catch the fuel. Make sure nothing looks damaged or like it needs to be replaced. The yellow thing with the mesh on the bottom of the assembly is an intake filter for the pump; make sure it's not clogged or torn.

 

Remove Lower Fuel Pump Bracket
 
  There is a bracket on the bottom of the assembly that supports the fuel pump. It's held in place by a Phillips screw, which is frequently really stuck on there. I went straight for the impact driver to get this one loose, but you can try a normal screwdriver if you like. Don't strip the head of this screw or you will hate life.

 

Remove Pump Inlet Filter
 
  The fuel pump inlet filter is held in place by a little clip that can be removed by inserting a small flat-blade screwdriver under the edge and prying it off. Work around the edge like you would the lid on a paint can.

 

Disconnect Fuel Pump Wiring
 
  Remove the nuts on the studs coming out of the fuel pump and disconnect the wires. Remember which wire is which! If you don't take note, then remember that the negative (-) terminal of the pump gets connected to the wire that attaches to the metal part of the assembly, which is grounded to the chassis. The positive connection uses a 7mm nut and the negative connection uses an 8mm nut.

 

Remove Fuel Pump From Assembly
 
  Carefully wiggle and/or rotate the fuel pump so that you can remove it from the assembly. The only thing holding the pump in place at this point is the rubber O-ring that provides the output seal. Be careful not to tear this O-ring if you plan to reuse it.

 

Remove Cap, O-Ring, and O-Ring Support
 
  Remove the two plastic pieces and the O-ring from the output of the pump. You'll need to reuse these on your new pump.

 

Compare Old and New Pump
 
  Make sure they're the same size and have the same connections.

 

Replace Cap, O-Ring, and O-Ring Support
 
  Just like you took them off of the old pump.

 

Lubricate O-Ring and Reinstall Pump
 
  Put a little WD-40 or some other lubricant on the o-ring before reinserting the pump into the housing. Failure to do this may cause the O-ring to tear upon reinsertion.

 

Reconnect Wiring
 
  Connect both the positive and negative wires to the new pump.

 

Install Pump Inlet Filter
 
  I used a small socket to press the clip back into place.

 

Reinstall Pump Lower Support Bracket
 
  Reinstall the bracket and make sure the screw is on tight. Don't strip it!

 

Reinsert Pump Assembly Back Into Fuel Tank
 
  Maneuver the assembly back into place. Make sure to hold the fuel vapor return line out of the way and take care not to bend the fuel level switch float arm. Align the holes in the pump with the studs on the tank and drop it down.

 

Tighten Fuel Pump Assembly Nuts
 
  The service manual doesn't list a torque spec for these bolts, so use common sense. They're pretty small studs, so snug them up, but don't crank on them.

 

Reinstall Fuel Hose and Tighten Upper Connection
 
  Reinstall the hose and rotate it to tighten the upper connection. The torque spec for this connection is 25 ft-lbs. Don't ask me how to get a torque wrench in there. I just used my finely-calibrated fingers to tighten it to 24.924 ft*lbs. Or was it 24.925?

 

Reconnect Lower Fuel Hose Connection
 
  Put it back just like it came off. The torque spec is 22 ft*lbs. Again, I used my digital torque wrench. Digital. Get it? ;-)

 

Reconnect Fuel Pump Wiring Harness
 
  Stick it back on there and make sure it clicks to indicate a solid connection.

 

Pressurize System and Check For Leaks
  Perhaps the easiest way to do this is just to start the car. I chose to use my datalogger's fuel pump test feature to turn on the pump without starting the car. This allowed me to listen for leaks without exhaust and engine noise. Another way to test only the fuel pump is to connect to the battery's positive terminal the blue test connector between the battery and the firewall. Only once you're sure there are no leaks should you proceed.

 

Replace Fuel Pump Access Panel
 
   

 

Replace RHS Cargo Tray and Spare Tire
 
   

 




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Last Modified Tue Dec 21 2004 14:48:05 Pacific Standard Time