Replacing a fuel pump on fj40 (2 Viewers)

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Joined
Mar 12, 2005
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My mechanical fuel pump on my 78 fj went out and I was about to get ready to change it out. What I thought was going to be an hour or so looks like it is going to take alot longer then that. I was wondering if it would just be better to put an aftermarket electric fuel pump on it instead of the stock mechanical one. Does anyone have any thoughts on this? Thanks, RG
 
Our '79 FJ-40 had the mechanical pump replaced by a simple electric pump. Worked fine. I didn't even realize it until I took the truck apart, that's how well it worked.

Just wire it to switch on with the key, and you'll be good to go.

Dan
 
The mechanical pumps last a very long time. I would replace it with an OEM. Good for another 30 years.
Should be a fairly easy process. I think it's two bolts and a pair of fuel lines and you are done.
 
unless you buy a good electric pump forget it .oem is best and its a half hour job to change for most people .unhook 2 fuel lines maybey 3 remove 2 bolts ,clean gasket surface and replace.i think your making this more diffucult than it needs to be .how long will it take to cut lines run wires and mount the electric pump right. your choice good luck
 
On a 78 there should be two lines, one rubber one hard.
Undo two bolts pull it out. Not much to it.
Buy a new gasket for it as well.
The 78 pump is rebuildable and can be torn down and rebuilt if needed.
Dave
 
The mechanical pumps last a very long time. I would replace it with an OEM. Good for another 30 years.
Should be a fairly easy process. I think it's two bolts and a pair of fuel lines and you are done.

X 3

Plus, if it takes you longer than an hour to replace the mechanical fuel pump, it'll take you even longer to remove it, mount the block-off plate, mount an electric pump, and figure out how to plumb it.

Our '79 FJ-40 had the mechanical pump replaced by a simple electric pump. Worked fine. I didn't even realize it until I took the truck apart, that's how well it worked.

Just wire it to switch on with the key, and you'll be good to go.

Dan

Not so much. That'll work, but there's a safety issue -- you don't want the pump fire-hosing fuel all over the place after you wreck and sever the line to the carb. Most EFI set-ups have a circuit that shuts off the fuel pump when it detects no ignition events.
 
Our '79 FJ-40 had the mechanical pump replaced by a simple electric pump. Worked fine. I didn't even realize it until I took the truck apart, that's how well it worked.

Just wire it to switch on with the key, and you'll be good to go.

Dan

I'd opt for the 1 hr. stock replacement option.

Most electric fuel pumps are designed to push fuel so you'd want to mount the pump on the frame rail back near the tank. Wire in a manual safety shut-off switch in the cab as well. Use something big and easy to hit when you're upside down.

The 78 pump is rebuildable and can be torn down and rebuilt if needed.
Dave

Where? Where? Where? I recently had to replace my fuel pump because I couldn't find a rebuild kit.
 
Just replaced my Fuel pump Yesterday went out to shop for one all i got is a 3F fuel pump so i got it plugged right in and Now it works perfectly 2 bolts and some hoses and your done
 
Replace with mech.Toy. should take less than 1 hour. Mike
 
definitely under hour of work
 
I will look at it again. I know the 2 bolts are all that hold the pump on but it was the other stuff like the battery box that looked like it was in the way. I will look again and check if I just saw it wrong.
 
Wire in a manual safety shut-off switch in the cab as well. Use something big and easy to hit when you're upside down.

Don't think this is something I would I count able to do in a accident. I know of one case where a FJ60 burned to the ground because the fuel line broke by the is distributor and the electric fuel pump just fed the fire even after the engine died. I looked at ways to primer the fuel system in my FJ62 because the fuel pump only starts with the starter and the MAF sensor has to see air flow to keep the pump running after the engines starts. Thinking about a seat belt warning relay that only works for a few seconds then shuts off.
 
Just put the new one in. Arm rides on a cam inside.
Some fuel pumps come with a spacer between the pump and the engine. If you have one of these, the gaskets go on both sides of the spacer. Otherwise you only need one gasket. Gasket sealer should not be needed if you have clean/flat surfaces but some prefer to use it. If you decide to use some, a thin coat of something like ultrablack should be good.
 
I see this is an old thread, but I'll chime in since I did it this morning. I had bought a new fuel pump last May (2015) as my mechanic said I needed one when they were changing out my F for my "new" 2F. I commented that I had just driven down from Quito with the new engine in the back of the rig and had no trouble. So I go buy a new pump, OEM no longer available. It is a sheet metal pump instead of cast like the OEM. I didn't like it. I took the OEM pump apart and while a new kit is not available, I found nothing wrong. So I cleaned it thoroughly, no pin holes in the diaphragm and put it back together and ran it until, November 2015 when the same mechanic changed the 2F from the '70 to the '79. At that time he tells me he took the pump off the '79 motor and put it on this one. Why? He said it was leaking. I never saw any leaking. So I ran it for two months and just two a three day trip in the mountains and it was bucking under load, running on after turning off the key, etc. So I put the sheet metal pump on it this morning and did run into town and it is performing much better. Still don't think there is anything wrong with my other pump.

So, like the fellow above mentioned, it is awkward to access. For me it was simpler to just remove the battery and support. Makes access to the two bolts much easier as well as for cleaning the surface. Still, less than an hour job. And I agree with everyone else, the mechanical pump is fine. I had looked online and I think it is Airtex that makes a new pump. Available in the USA for under $100 and looks like the OEM, cast body. I have used that companies products before and found them to be high quality. I will probably source a pump from them in the near future.
 
I see this is an old thread, but I'll chime in since I did it this morning. I had bought a new fuel pump last May (2015) as my mechanic said I needed one when they were changing out my F for my "new" 2F. I commented that I had just driven down from Quito with the new engine in the back of the rig and had no trouble. So I go buy a new pump, OEM no longer available. It is a sheet metal pump instead of cast like the OEM. I didn't like it. I took the OEM pump apart and while a new kit is not available, I found nothing wrong. So I cleaned it thoroughly, no pin holes in the diaphragm and put it back together and ran it until, November 2015 when the same mechanic changed the 2F from the '70 to the '79. At that time he tells me he took the pump off the '79 motor and put it on this one. Why? He said it was leaking. I never saw any leaking. So I ran it for two months and just two a three day trip in the mountains and it was bucking under load, running on after turning off the key, etc. So I put the sheet metal pump on it this morning and did run into town and it is performing much better. Still don't think there is anything wrong with my other pump.

So, like the fellow above mentioned, it is awkward to access. For me it was simpler to just remove the battery and support. Makes access to the two bolts much easier as well as for cleaning the surface. Still, less than an hour job. And I agree with everyone else, the mechanical pump is fine. I had looked online and I think it is Airtex that makes a new pump. Available in the USA for under $100 and looks like the OEM, cast body. I have used that companies products before and found them to be high quality. I will probably source a pump from them in the near future.
I see this is an old thread, but I'll chime in since I did it this morning. I had bought a new fuel pump last May (2015) as my mechanic said I needed one when they were changing out my F for my "new" 2F. I commented that I had just driven down from Quito with the new engine in the back of the rig and had no trouble. So I go buy a new pump, OEM no longer available. It is a sheet metal pump instead of cast like the OEM. I didn't like it. I took the OEM pump apart and while a new kit is not available, I found nothing wrong. So I cleaned it thoroughly, no pin holes in the diaphragm and put it back together and ran it until, November 2015 when the same mechanic changed the 2F from the '70 to the '79. At that time he tells me he took the pump off the '79 motor and put it on this one. Why? He said it was leaking. I never saw any leaking. So I ran it for two months and just two a three day trip in the mountains and it was bucking under load, running on after turning off the key, etc. So I put the sheet metal pump on it this morning and did run into town and it is performing much better. Still don't think there is anything wrong with my other pump.

So, like the fellow above mentioned, it is awkward to access. For me it was simpler to just remove the battery and support. Makes access to the two bolts much easier as well as for cleaning the surface. Still, less than an hour job. And I agree with everyone else, the mechanical pump is fine. I had looked online and I think it is Airtex that makes a new pump. Available in the USA for under $100 and looks like the OEM, cast body. I have used that companies products before and found them to be high quality. I will probably source a pump from them in the near future.
I’m in the process this weekend of replacing the fuel pump on my wife’s F motor.
Do you recall if the two oem fuel pump fittings are sealed from the factory or if you need to put some Thread sealer on them

21B54D17-1AE4-4B5E-8BA4-11DD1CED3CDD.jpeg
 
Hi folks
Just picked up a rare 79 fj55
It had a electric fuel pump that is no longer working, so I wanna place a new one on a switch to prime or kick on in this Arizona summer heat vapor lock
Question is I am also gonna go back to a mechanical fuel pump
So I have 2 fuel lines in the engine bay coming from the tank
The fuel pump I'm getting has 2 lines in and 1 line out to carb
Does someone have a pic or diagram to show me which line goes where?
I tried to find something but couldn't

Any help appreciated

Pic if my iron pig
IMG_20200710_093143_814.jpg
 
This is a very old thread that has a lot of FJ40

I don’t know FJ55 or 1979... you’d probably have more luck by creating a new thread with “1979 FJ55 Fuel Line Questions” or something that specifically mentions the year and the model.

Good luck!!
 

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