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Prepping for fuel pump install


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I have an '84 720 and am getting ready to install a fuel pump. Since I am inexperienced, I thought I would compile a pictorial of what I am doing.



Shield off, ground view.


Removed the four 10mm screws after a good soak in PB Blaster.







The hose from the tank is really short, and there is not a lot of room.


Would like to have put a more costly pump in, but this is what I can afford.


After Easter celebrations are over I will get started. I will do the fuel pump, new belts, and new hoses. The budget is tight this year, so hoping some maintenance will keep things going for a while.


Happy Easter to all!

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Here is the rest of my truck from what it was when I got it, and how it looks today.


Original and a little rough but all there,


Washed, ready for some body work.


Body work done, painted (close your ears) Lexus green.


Check out the fabbed bumper.


Love this site. Thanks especially to Datzenmike for his patient responses to my questions.

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How did you determine the pump was bad? those pumps usually last a really long time. 

It would run for a while and the shut down like it was fuel starved. Several people told me that it sounded like a thermal problem. So I got a pump, installed, and it ran for a while and shut down. I looke in the carb and it was dry.


Here's the install. I must have installed incorrectly or I have another problem.




The first law of being a noob is to not fear embarrassing questions if they bring answers with solutions. So, did I screw it up? I've heard of relay problems, and a filter somewhere in the carb. The carb scares me as that is probably beyond my skill level.


Thanks for the response.

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Pull the filter off and see if plugged. Maybe get a cheap in line filter you can change easily.


The pump may have a thermal overload to shut it off.


When installing it did fuel siphon out thw hose at all?

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Can you look at the photo above and tell me which end is inlet and outlet? Thanks a lot.


Those pumps are usually stamped IN/OUT.  


The "small" end with the filter on it in the above pic is usually the inlet on all the ones I've used.

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Hyspeedz -

Last time I was at the wrecking yard I was peeling some parts off an '85 720 KC.  A guy came by looking for a fuel pump.  The bed was off the truck, so that made it a little easier, but he had the pump off in minutes.  Have you thought about going that way?  Assuming the wrecking yard pump was good, you could wire it up just like the original.  That way you're reducing some of your variables.


I imagine a loose fuel pump could be tested by hot wiring it to the battery for a second, just to see if it spins?  Maybe not.  Maybe running it dry can damage it.


At about 2:30 into

, they show a very similar aftermarket pump with the "OUT" stamp on it, confirming what WideFive said.


EDIT:  Just another comment in case you go to a wrecking yard.  I can't tell from your picture, but did you cut the original wiring off on the truck side of the round plug?  Or is the factory plug still intact and you cut the wiring on the pump side? 

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Hey guys, thanks for all the great suggestions. I kept the original wiring harness, soldered the wires, and got a good ground. When I reconnected the negative battery cable, I could hear the pump prime. It works great. Took it out for a drive, and maybe it's my imagination, but it feels stronger. Probably uncalled for exuberance on my part. Next up, fan belts and rad hoses.


Thanks again for the great help. This noob appreciates it.

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