Fuel Sending Unit Fixed

07-03-2005, 10:03 AM
After a month and a half of estimating my fuel capacity I finally got around to dropping my fuel tank during Canada day on Friday.
I pretty well followed the write up. The difficulties I encountered were that one (typical for me) of the bolts holding up the gas tank would not come off. So out came my Husky air impact gun and I broke the head of the bolt off (opps). Big advice- spray all bolts with penetrating oil everyday for several days in advance. So now there was no turning back and I took out the tank.

I took some figuring out how to disconnect the fuel lines. I never have seen these quick connects before. I figured out that I just squeeze the clips and pull. A bit of gas came out of the line. I then pulled out the tank from under the car. You should really clean the top of the gas before you take out the fuel pump. I used compress air. Looking back I would siphon out the rest of the tank and wash the top of the tank with a cleaner. You would be surprised how much dirt, rust and flaking paint accumulate around the fuel pump opening. I took off the snap ring and gently(gently gently) pryed up on the plastic lip of the fuel pump. There is a big blue rubber o-ring that is tightly holding the fuel pump in tank.

Out came the fuel pump and I inspected the fuel sending unit. The bottom electrical prong contacts had warped away from the contacts mating surface. After seeing this I came to the conclusion that the male contacts were made with the wrong alloys or are too thin of a guage or both. There was no burning of the contacts. My conclusion wasthat when certain additives were introduced into the gasoline (by the gas company or by you using fuel injector cleaners) a chemical reaction occurs heating up the male connector and making it curl away from the contact surface. For those that had their male connectors burn to nothing, my guess is that the contact did not curl and were slowly heated away.

I now gently disconnected the fuel sending unit from its seat. I kept the wires connected you just have to compress the fuel pump to give youself some slack. Everything is prefaced with the word GENTLY. Remove the float arm. Turn the fuel sending unit upside down on a wooden board and GENTLY tap out the center pivoting bearing. The fuel pump and fuel sending unit is mostly plastic Do not put enough pressure to break anything. Once the swing arm is disconnected use needle nose pliers and straighten out the male contact and bend the contact so you are going to have more spring pressure against the mating surface. I put every thing back together and went to wash the tank out. While waiting for the fuel tank to dry I took off the drive shaft and put in new grease on the two piece shaft.

Now for the fun part, drilling out the broken bolt. I pushed the 3/32 pilot bit to hard and broke it about 3/4 in. in the bolt. Out comes the 1/4 masonary bit. I sharpen it on a little diamond wheel I have. I got about 3/8 into the bolt and I was exhausted so I turned to the soldering torch and heated the metal up around the bolt. I was able to get some vice grips on opposite end of the bolt and turn it loose.

Now that the fuel tank is dry, I get the fuel pump and thinly lube up the big blue o-ring and the mating seat with dielectric grease (I didn't want to use any bearing grease). The fuel pump is hard to seat when the o-ring is dry. Push the pump down untl you can get the snap ring back on. I now sprayed electrical conntact cleaner in the electrical connectors and blew them out with compressed air. Put the fuel lines back on the same way the came out. Get the jack under the tank, lift into place tighten the bolts and one nut. Since it was a holiday I used a toggle bolt in place where I broken bolt was. The next day I went out and bought a M10x30mm bolt and put it in. Re-attach filler lines, put back fuel pump fuse, touch the two disconnected battery wires together for a minute to reset the pcm to factory settings. Re-connect the battery wires to the battery, fill with gas, turn over the engine a couple of times until it starts and everything works fine now.


07-03-2005, 02:33 PM
or program for this. Izusu had a program to fix these. There was a TSB, and it should have been under warranty.

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