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Geocritter's avatar
Geocritter
Explorer
May 09, 2014

Some question regarding in-tank fuel pump replacement

So, all y’all have me convinced that my engine problem, explored in the earlier thread titled Unexpected engine failure (shut down) 1994 Ford 460 V8, is a bad fuel pump. I’m not sure which route to go, install a secondary in-line fuel pump or replace the in-tank fuel pump. As a result I’ve decided to also explore replacing the in-tank fuel pump on my rig. I’m not sure when I'll do the work, but I figured it couldn’t hurt to scope it out well first. I stuck my digital camera up between the tank and the floor and got these photos.



The top of the fuel pump is clearly visible with the outlet and return gasoline lines as well as the electrical connection. Next to it on the right is something; I’m thinking it’s part of the fuel tank ventilation system.



Here’s a close-up view of the two items mentioned in the first photo.
My question at this point is, where is the gas gauge assembly, is it part of the fuel pump? The gas gauge is erratic to the point of being worthless, yet other than the two items pictured on top of the tank I can’t find anything that looks as if it has anything to do with the gas gauge.

In addition, I’ll not only have to cut an access hole through the floor but through the main furnace duct pipe as well. However, it’ll be easy to install a sheet metal patch in the duct pipe when I’m done. I’ll use sheet metal screws and silicone caulk so if need be I can remove it in the unfortunate event I have to work on the fuel pump again. As for the floor, I’ll just use the access panel I cut out to repatch the hole.

Man o man, ain’t these old relics fun!
  • Teacher's Pet wrote:
    Good luck, we've paid twice to have them replaced, both times happened on a trip.

    When I replaced the one on my Caravan I'd had it replaced twice earlier at a garage, the third time I told them to give me the pump and I'd do it myself. I couldn't find anything wrong with their installation but the new pump I put in worked fine and gave me no more trouble. Third times the charm???
  • jfkmk wrote:
    Yeah, the sending unit for the gas gauge is usually part of the fuel pump unit. This can be a very dangerous job. If you attempt it, make sure you use non-sparking tools.

    I replaced the in-tank pump on a Dodge Caravan once and it scared the heck out of me! The minute I took the pump out, and I could see the gasoline fumes pouring from the tank, all I could imagine was a huge fireball with me in the center. Probably the best thing is to make up ground clips to ground my tools to the RV frame and then ground the RV frame to a nearby water faucet connection coming from the ground alongside my RV. The last time I replaced a in-tank pump I prayed that I'd never have to do it again. I hate to sound cynical but so much for the power of prayer.
  • Yeah, the sending unit for the gas gauge is usually part of the fuel pump unit. This can be a very dangerous job. If you attempt it, make sure you use non-sparking tools.