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Submariner

engine truns over but won't start. I athink itis the fuel pump.

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first i am driving a 88 Comanche, 4.0 5 sp 2wd (right now)

 

It has been going good, starting right up and going down the road.  now it just cranks.  towed it home.

It has been raining cats and dogs,  I have water on the floor boards.  I need to find the leak, latter.

Now no fuel pressure in the rail.  by pass the resistor, nothing.  I have not  put a hot wire to the fuel pump yet, ran out of day light.

I have been having fuse issues in the last few days, gages not working, heater core not working,  wiggle fuses and it ok.

now this.  I need some suggestions on what to start with besides pulling out the fuel pump.

and where is the fuel pump anyway?  in the tank i bet.

 

Any suggestions would be helpful

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it is in the tank. :L:  keep in mind that it could be a lack of power or a lack of ground.  do the rear lights work?  one of the easiest things to check is the pump grounding location behind the drivers side taillight.  there's also a connector right behind the drivers side rear tire that can get corrosion inside. 

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i will check that.  about two weeks ago I put in a trailer light hookup.   I wonder if I screwed something up then and it finally is giving me fits.

Thanks for the idea

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Taillamps and fuel pump share the same ground....

 

Here's something to look into.

 

 

IMPROVING THE FUEL PUMP GROUND

 

The fuel pump and fuel tank sending unit ground at a sheet metal screw up behind the spare tire on an XJ, XJ-Body-Ground.jpg?resize=300%2C162and behind the driver’s taillamp on an MJ.

Not only is a sheet metal screw a lousy way to ground things, this ground path is long and travels through some connectors that are prone to corrosion and moisture.

Locate the black wire on  the HARNESS side of the fuel pump/sender 3 wire connector. Remove a 6″ length of the split loom covering. Strip back about 1/2″ of insulation from the BLACK wire.1-fuel pump ground MJ

Take your new ground wire, preferably at least 14 gauge and 12 to 18 inches long as needed, strip it about 3/4″, and wrap it around the exposed part of the harness plug wire.1-fuel pump ground mj-002Solder the connection. Tape it up and reinstall the split loom covering.1-fuel pump ground mj-003

At the other end of your new ground wire, add a crimp on eyelet. Attach the eyelet under a bolt that goes directly into the chassis. Be sure to clean the attaching point til shiny and apply OxGard to the contact surfaces.1-fuel pump ground mj-004

 

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What is this?  When I put 12 volts to the wire that goes to the fuel pump, this clicks.

I am not getting any fuel pump action yet.  could not get to the back of the truck today.  In the morning i will get after it.

I am not get any power to the connections to the resistor.  I checked with a volt meter.

 

I do have tail light, turn signals and brake lights

what is it.jpg

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EGR valve solenoid. Powered by the same voltage that powers the fuel pump.

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If you have assistance, have someone crank the vehicle, at the same time tap on the bottom of the fuel tank. This usually wakes up a failing pump and your truck will run again, but the pump still needs replacement.

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30 minutes ago, Submariner said:

When I put 12 volts to the wire that goes to the fuel pump, this clicks.

 

Did you remove the wire from the ballast to do this? If so, may be the EGR solenoid side and not the fuel pump side (the other one).

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38 minutes ago, Submariner said:

I am not get any power to the connections to the resistor.

 

With key ON and engine not running, power is only there for 2-3 seconds.

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ok, I will try the "hit the bottom of the tank" in the morning.

 

I have a standby egr valve to test the old one.

 

and I will see what happens when I turn the key on, I will get an assistant.

 

So hwat is easier to replace the fuel pump.

 

Take the bed off or drop the tank?  right now the tank is full of course.   lol ain't that the way it is.

 

And can I use a fuel pump from a 89 Cherokee to replace it.

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the tank is bolted to the bed, not the frame.  :L:  but don't worry, if you're agile, you can swap the pump while under the truck.  the opening is in the side of the tank, not the top. :D  

 

which wire did you apply 12 volts?  and don't forget that it takes 12 volts and a good ground to activate the pump.

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I used the wires that go to each side of the Ballast resistor.   I did a volt test and I was 12.28 volts at the battery.  got 1 volt at the ballast resister wires.  ran a hot wire from the battery to the resistor wires and nothing happened but the click or i should say a thump in the back and a click at the egr

 

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Truck started.  not sure why.  PFM

beat the bottom of the tank

redone the ground at the taillight

disconnected the the connection that goes to the fuel pump and reconnected it

removed the bypass for the ballast resistor and reinstalled it.

 

I am thinking that it was PFM, ole submarine term, Pure Fu#$ing Magic.

 

But it started and is running as we speak.

 

When I put it down in a few weeks for upgrade to 4wd, a new fuel pump is on the list now for replacement.

 

I am so temped to pull all the wiring and replace only what is needed to make her go around the block. get rid of all the extra stuff that is in there like A/C, electric windows, cruise and other stuff that is not needed.  That is one of the many things that I am contemplating in the near future.

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