1979 FJ 40 Fuel Pumps (1 Viewer)

[uwum15]

I have a '79 FJ40, I think was made in January of '79 and I believe it might be the Asian model engine because I went to change out the AUX diaphragm on the carb and mine didn't have one...My fuel pump went out & I can only find a new pump with a third return fuel line whereas the one I had only had two lines. I bought it but I don't get the same compression or pressure of fuel to the carb-it isn't running well and feels sluggish. Does anyone know a good way to plug that or is there a trick to make it work better? Without plugging that return fuel line it stalls out all the time, but with it capped it still isn't performing like it should (with the spacer on the engine block it mounted on fine just like the one it replaced) but quite a bit better. Thanks in advance,
Devin

 

[Racer65]

Can you show a pic of the old pump?

 

[3_puppies]

I have a '79 FJ40, I think was made in January of '79 and I believe it might be the Asian model engine because I went to change out the AUX diaphragm on the carb and mine didn't have one...My fuel pump went out & I can only find a new pump with a third return fuel line whereas the one I had only had two lines. I bought it but I don't get the same compression or pressure of fuel to the carb-it isn't running well and feels sluggish. Does anyone know a good way to plug that or is there a trick to make it work better? Without plugging that return fuel line it stalls out all the time, but with it capped it still isn't performing like it should (with the spacer on the engine block it mounted on fine just like the one it replaced) but quite a bit better. Thanks in advance,
Devin

Devin, if your original pump had 2 lines and you installed the 3 line pump WITHOUT the spacer, you just trashed the new pump.
If you rig is a Jan 79 build it may have been 1 of the last of the 78 model year which only had 2 lines on the pump and the return was from the carb. the later 79 had the return at the pump thus using 3 lines at the pump. Is your gas tank in the cab or under the body?
You can get a 78 pump and you would be good to go.
rule is 3 lines at pump needs a spacer, 2 lines no spacer.

so just reread you post, you had a 2 line pump with a spacer?
pics of old pump?

Paul

 

[greenbeast]

Contact Onur at Landcruiser consulting, he should be able to offer some help pm "beno" which is mud name.

 

[uwum15]

This is the old pump on top with the new 3-arm below...I'll keep searching but I can't find the 2-arm pump anywhere online. The spacer that was with the old pump is still mounted to the engine block and I reused it when I put the new one on. Thanks again for any help.

 

[uwum15]

Can you show a pic of the old pump?

I posted a pic for you, thanks in advance.

 

[uwum15]

Devin, if your original pump had 2 lines and you installed the 3 line pump WITHOUT the spacer, you just trashed the new pump.
If you rig is a Jan 79 build it may have been 1 of the last of the 78 model year which only had 2 lines on the pump and the return was from the carb. the later 79 had the return at the pump thus using 3 lines at the pump. Is your gas tank in the cab or under the body?
You can get a 78 pump and you would be good to go.
rule is 3 lines at pump needs a spacer, 2 lines no spacer.

so just reread you post, you had a 2 line pump with a spacer?
pics of old pump?

Paul

I just posted a picture of it with the new/old pumps together. Thanks for whatever you can shed light on.

 

[3_puppies]

I don't recall ever seeing a 2 line pump that looks like a 3 line pump. the 2 line pump is a different shape with shorter arm so no need for a spacer.
Maybe Mark A. or someone else has seen this before.

Does your carb have a return line from it back to tank?

Napa should be able to get a 2 line pump from a 77 or 78 or Beno or CDAN for OEM

 

[uwum15]

I found a mechanic in town that owns two FJ40s so I feel like the following might be true: he thinks the 3-arm with the return line is correct and has 12 inches of pressure when it's hooked up. He thinks my new fuel pump is good but the problem is a faulty fuel tank pickup tube since he is seeing some air in the air filter. I have searched high and low and cannot find one for sale; does anyone have any ideas where to find this at, and if that makes sense as a fix? As always, thanks and I think I'll start a new thread for fuel tank pickup tubes.

 

[Solace in Solitude]

I have an 01/78 FJ40... My OEM fuel pump is a 2-line: one soft line, from hard line on frame rail to pump; one hard line, with threaded connection, from pump to carb.

I bought an OEM replacement (new) from either @beno or CDan... I carry the old pump as a spare.

Check with Onur (Beno).


I use NO spacer and run a return, from the carb to the fuel tank.

I have since added an Aus tank and run both tanks, using the OEM pump, a 6-port Pollak switching valve, OEM gauge and DPDT switch. The item pump puts out 3-5 psi, which is what the Aisin carb wants.

I also run a fuel filter on the feed line, downstream from each tank.

HTH

 

[uwum15]

I have an 01/78 FJ40... My OEM fuel pump is a 2-line: one soft line, from hard line on frame rail to pump; one hard line, with threaded connection, from pump to carb.

I bought an OEM replacement (new) from either @beno or CDan... I carry the old pump as a spare.

Check with Onur (Beno).


I use NO spacer and run a return, from the carb to the fuel tank.

I have since added an Aus tank and run both tanks, using the OEM pump, a 6-port Pollak switching valve, OEM gauge and DPDT switch. The item pump puts out 3-5 psi, which is what the Aisin carb wants.

I also run a fuel filter on the feed line, downstream from each tank.

HTH

Thank you, I'll check into that. Have you ever had a problem with the fuel tank pickup tube? That was another idea my mechanic had because I can get the 3-arm pump with a return fuel line back to the tank. It all seems great but I'm not getting enough psi (really none) when all three lines get hooked up which leads him to think the pickup tube might be an issue.

 

[georgia fj40]

@Racer65 has OEM fuel pumps as well. Check out his site found in his signature, he posted earlier in your thread.

 

[Solace in Solitude]

No, I've never had problems with the pickup line... But, I've read where others have.

You should make sure your hard lines, along the frame rail are clear. They are the lowest point in the fuel system in a '78 and they are subject to collecting water and gunk. Disconnect the soft line in each end of those hard lines and blow them out with compressed air. Then shoot some brake cleaner in them and flush them out.

While you have them disconnected, try shooting compressed air into th tank, thru the fuel feed line.

Once you hook it back up, you should see a good fuel flow. If so and it slows down again, you should consider removing your tank and cleaning it out.

I don't recall how th three-arm lump works... Does the return return thru the pump? Are you sure your tank is properly plumbed? E.g. Is there a breather line from the tank to near the top of the filler neck? You could have too much pressure in your tank to allow the fuel return to work... Also preventing your pump from pumping from th tank.

 

[uwum15]

No, I've never had problems with the pickup line... But, I've read where others have.

You should make sure your hard lines, along the frame rail are clear. They are the lowest point in the fuel system in a '78 and they are subject to collecting water and gunk. Disconnect the soft line in each end of those hard lines and blow them out with compressed air. Then shoot some brake cleaner in them and flush them out.

While you have them disconnected, try shooting compressed air into th tank, thru the fuel feed line.

Once you hook it back up, you should see a good fuel flow. If so and it slows down again, you should consider removing your tank and cleaning it out.

I don't recall how th three-arm lump works... Does the return return thru the pump? Are you sure your tank is properly plumbed? E.g. Is there a breather line from the tank to near the top of the filler neck? You could have too much pressure in your tank to allow the fuel return to work... Also preventing your pump from pumping from th tank.

We did find a problem in the hard lines attached to the frame by the passenger door so we are fixing those this week. They still think there's more of an issue so I'll try your ideas about the tank as well once that is done. Thank you for the help; as for the pump I believe it does return through the pump and then back. I'm sure it'll take a little while but I'll try to get you an update.