1G Fuel System Upgrade

Posted: Fri Mar 31, 2006 9:40 pm

The following is courtesy of, and written by, Devioustsi and final assembly images by liquidnote.

1G Fuel System Upgrade

If you happen to break the fuel line (like our very own liquidnote) during a fuel pump install. Then instead of searching junkyards for a sending unit ( because no aftermarket or new mitsu ones are available). You could upgrade your own fuel system and build it better than factory standards.

Parts List-

1x Slowboyracing fuel rail inlet fitting $25

1x 90 degree -6an hose end

1x 45 degree -6an hose end

2x straight -6an hose end

15 feet -6an ss braided line

1x 90 degree bulkhead connector -6an

1x bulkhead nut

1x Barb to -6an fitting

1x 3/8npt inlet/outlet fuel filter

2x -6 AN Male to 3/8 in. NPT Male

6 inches high pressure fuel injection line from local parts store

2x hose clamps

2x nylon crush washers

You could use this as a guide line but use the parts I suggested.

This way there are absolutely no restrictions in the fuel system.

Compared to the way this fuel setup is...which still uses the stock outlet of the tank.

Step 1: Remove stock fuel pump.

Step 2: After removing the stock fuel pump you will need to drill the hole for the bulkhead adaptor in the sending unit mounting flange. I recommend using the stock outlet hole. First cut or break the old line off flush with the top of the sending unit. Next drill the hole out large enough to fit the bulkhead adaptor through and the line inside of the sending unit will fall off. It should look like this...

Step 3: Mount your bulkhead adaptor through the hole with a nylon crush washer on each and the nut last to tighten it down.

Step 4: Tighten the barb adaptor down and remove black sleeve/collar.

Step 5: Mount your fuel pump and run the high pressure hose from the pump to the barb adaptor and install the hose clamps.

One thing I would recommend doing differently than pictured would be to replace the zip ties on the fuel pump to 1 or 2 worm gear clamps. I have seen set ups with just the zip ties cause problems. For instance the pump will fall off the sending unit or the pump moves enough to cause the fuel line to seperate. The zip ties just become brittle over time with the fuel.

Now would also be a good time to rewire the fuel pump with 10-12 gauge. Just drill a hole through the top of the sending unit large enough to get the new wire through. Then j.b. weld the hole/wire shut from both sides. Then just follow one of the vfaq's for the rest of the rewire.

On my own personal car I ran 12gauge positive and negative wires through the sending unit this way. I connected the negative inside the sending unit from the pump to the stock position with 12gauge and a ring terminal. Then I ran another ring terminal 12gauge off the same point through the sending unit to my rear mounted battery for a good ground. Rewiring the positive is only half the wiring of the fuel pump, ya know. The stock wiring uses the tank as the ground, and if you have a lot of rust it could reduce the quality of the ground.