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Hey so I recently started pulling the comanche apart. In the process I pulled all of the vaccuum lines off. Coming off the fuel rail it looks like some sort of vaccuum operated valve? What does it do and do I need it. Also my fuel pump isn't coming on anymore. Are the 2 things related? If not where is the ground for the fuel pump located as I recently had both tail lights apart.

It's a 1989 4.0 4x4 LWB.

Thanks

Justin

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Where is the valve? If its at the front of the fuel rail, its the fuel pressure regulator, and yes you need it. Fuel pump ground is behind 1 of the tail lights, not sure which one

 

Drivers side taillight bucket...and it shares that ground with the fuel pump.

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Where is the valve? If its at the front of the fuel rail, its the fuel pressure regulator, and yes you need it. Fuel pump ground is behind 1 of the tail lights, not sure which one

Yes so it is my fuel pressure regulator. Is it vaccuum acuated? If so does anybody have a vaccuum diagram?

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So I figured out the pressure regulator and have came to the conclusion that my fuel pump is shot. Firstly it doesn't turn on even though I have a good ground and power to the pump. Secondly the gas gage goes past the full mark.

My next question is has anybody ever put a gas tank from a ford pickup with the pump in the tank into their comanche? If so does the in tank pump provide enough pressure, as I know the fords also have a pump on the frame.

Thanks

Justin

 

Also, is there a way I can change the topic name, as I would rather have a general question thread, due to unforeseen problems and not wanting to have to many questions cluttering up the board.

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So I started putting an xj fuel tank in the box. I am not gettin power now. I have a good ground (to the headache rack). I think it might be a fuse or relay, could anybody point me in the right direction? Also where is the pressure regulator thats kicks the pump out after a certain psi?

Thanks again

Justin

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88pioneer pointed out where the fuel pressure regulator is located, on the front of the fuel rail, and YES you need the regulator to control pressure. You should be getting 31psi at the test port, 39psi with the pressure regulator dis-connected.

 

The fuel pump relay in on the B-tower, on the right fender, the second from the front.

 

You also have a ballast resistor mounted on the left front fender, the white porcelain looking thing, that's has a pair of orange/black tracer wire feed in series thru it.

 

So.........what are your goals with pulling all the vacuum lines out, and running an XJ tank in the bed????? :dunno: :hmm:

 

Also........check you tank ground, to the "headache rack" :dunno: run a ground back to the engine ground stud and you'll know you have ground.

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88pioneer pointed out where the fuel pressure regulator is located, on the front of the fuel rail, and YES you need the regulator to control pressure. You should be getting 31psi at the test port, 39psi with the pressure regulator dis-connected.

ok thanks

 

The fuel pump relay in on the B-tower, on the right fender, the second from the front.

Thanks, mine weren't marked.

 

You also have a ballast resistor mounted on the left front fender, the white porcelain looking thing, that's has a pair of orange/black tracer wire feed in series thru it.

 

I have already bypassed the resistor.

 

So.........what are your goals with pulling all the vacuum lines out, and running an XJ tank in the bed????? :dunno: :hmm:

 

I pulled the lines when I had the header panel off as I didn't know I needed them (Thinkin H.O.) I am putting a xj tank in due to mine having multiple holes, and not having a spare comanche one.

 

Also........check you tank ground, to the "headache rack" :dunno: run a ground back to the engine ground stud and you'll know you have ground.

 

Tank ground is good as headache rack is grounded right to the negative battery terminal as suggested.

thanks for all the help :cheers:

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