Fuel line/pump question

[Joop]

On a '86 2.8L... which one of the 2 fuel lines thats connected to the tank is the fuel delivery? One is 8mm and the other 10mm.

 

 

Right (towards the rear of truck) is 8mm and left (towards the front) is 10mm

 

This is how they look where they end up right next to the brake sylinder:

 

 

Whats the purpose of the little 6mm pipe there? The other end is connected to the grey hose you can see going trough the first picture.

 

Stupid me forgot to take out the tank unit from the '90 XJ i pulled the renix 4.0L from, but i found a volvo-type injection pump thats designed to be installed outside of the tank. Hoping that should do the job just as well, its really beefy looking.

 

By the way, does anybody know where the fuel pump get its power from? The wiring diagram is kinda confusing me and i havent tagged any of the wires from the renix with "fuel pump" (stupid me again :wall: )

[chicofuentes0224]

On my 88 4.0 the color is orange if that's what you are asking.

[Joop]

On my 88 4.0 the color is orange if that's what you are asking.

 

Thanks!

 

Anyone know something about those fuel lines?

[512tr]

On a Renix the 3 lines from the fuel tank are:

 

Fuel supply (10 mm) connected to the rear of the fuel rail.

 

Fuel return (8mm) connected to the fuel pressure regulator at the front of the fuel rail.

 

The small one is connected to the fuel vapor canister.

[Eagle]

On a '86 2.8L... which one of the 2 fuel lines thats connected to the tank is the fuel delivery? One is 8mm and the other 10mm.

 

 

Right (towards the rear of truck) is 8mm and left (towards the front) is 10mm

 

This is how they look where they end up right next to the brake sylinder:

 

 

Whats the purpose of the little 6mm pipe there? The other end is connected to the grey hose you can see going trough the first picture.

 

Stupid me forgot to take out the tank unit from the '90 XJ i pulled the renix 4.0L from, but i found a volvo-type injection pump thats designed to be installed outside of the tank. Hoping that should do the job just as well, its really beefy looking.

 

By the way, does anybody know where the fuel pump get its power from? The wiring diagram is kinda confusing me and i havent tagged any of the wires from the renix with "fuel pump" (stupid me again :wall: )

Jop, I don't think you will find much help from us in the U.S. because over here the 2.8L was set up with a mechanical fuel pump and a carburetor. Nobody here has a vehicle that is equipped like yours.

 

You have a 2.8L V6 that has an electric fuel pump? Is it fuel injected?

[Joop]

Jop, I don't think you will find much help from us in the U.S. because over here the 2.8L was set up with a mechanical fuel pump and a carburetor. Nobody here has a vehicle that is equipped like yours.

 

You have a 2.8L V6 that has an electric fuel pump? Is it fuel injected?

 

It was a 2.8 identical to the US version with carb and mechanical pump. Now i have a 4.0L renix there and I'm trying to figure out a way to feed it with fuel since i don't have the tank sending unit with all wires, fuel lines and stuff from the 4.0L donor veicle. In theory i could just cut the fuel feed line and put in any kind of pump, as long as it delivers enough fuel at high enough pressure.

[Eagle]

It was a 2.8 identical to the US version with carb and mechanical pump. Now i have a 4.0L renix there and I'm trying to figure out a way to feed it with fuel since i don't have the tank sending unit with all wires, fuel lines and stuff from the 4.0L donor veicle. In theory i could just cut the fuel feed line and put in any kind of pump, as long as it delivers enough fuel at high enough pressure.

Aha! Je comprends.

 

It is possible to use an external, electric fuel pump. I think it needs to produce 40 psi, though, so you can't buy an older pump that would be used with a carburetor, because those only put out about 7 psi. What do you have? Is that photo of what appears to be a 4.0L Cherokee fuel tank the tank out of your 4.0L donor vehicle? Does the fuel pump function?

[Joop]

Both pictures are from the MJ, showing off the original 2.8 stuff.

 

Got this brand new pump cheap from the local "everything-you-need-and-don't-need-for-whatever-car-you-have" store

 

*bling-bling*

 

don't know the exact specs for it, but its from late-80s turbo volvos and I'm 99% shure it should deliver enough juice to run the 4.0

[FxRacing282]

yeah if its built for a turbo then it probably has enough output pressure to feed the 4.0

[512tr]

I assume you have the computer and relays from the Renix 4.0, then you have to use the fuel pump relay to supply power to the fuel pump.

 

The output from the fuel-pump relay also supply/trigg the EGR solenoid, O2 heater relay, AC clutch relay.

 

 

The fuel pump relay ground circuit is controlled by the ECU, and thus the ECU activate the fuel pump when the engine is cranking or running (And 1-3 sec when the ignition is turned on, enough to pressurize the system). On idle, the pressure reach 31 PSI, then the pressure regulator opens and maintain max 31psi by sending fuel back to the tank.

 

I think if you are using an aftermarket fuel pump, it has to have at least 90-100 psi max pressure.

 

Sure you can make your own wiring to the fuel pump, but still you have to use a relay (fuel pump relay on the Renix) in order to operate the EGR solenoid, O2 heater relay, AC clutch relay.