My 85 6.9 ran out of fuel at 1/4 tank. Something wrong inside the tank. I could only pump 10 gallons out of each tank. Learned the hard way, along side the road.

 

Marianna2003, I appreciate the input. My electric fuel
pump is mounted on the main frame underneath the drivers
seat, just forward of some kind of switch that probably
selects which tank is being used. As far as I can tell,
the fuel goes from the ep directly to the fuel filter and
to the injection pump. Having an electric pump, I figured
there wasn't a mechanical one. I'll look a little closer.

 

If it happens again, leave your fuel pump on and try to bleed air from the filter. The only way air could be in the filter after bleeding it and running 15 miles is a leak between the tank and the EP. If there is air in the filter, you could coat all of the joints with liquid electriacl tape to effect a perfect seal.

 

Sorry I started to reply to another thread.

 

The more I work on something, it seems like the more it
has additional problems. I could see that the left front
injector wasnt tight...bubbling around the bottom and
I couldn't tighten it enough to get it to quit. I took it out,
but in doing so I broke the little plastic thing a ma jig that
mounts on it and only comes with a kit. I picked up another
injector, probably only need to clean out the carbon out of
the threads and fish out the copper washer and use the
old one may be. I also got the kit to replace the plastic
thing. I live about 40 miles away from most everything so
when I go to get parts half a day is gone. I'll work on it
some more tomorrow. Thanks.

 

OK, now we are getting somewhere.

Since you have an electric pump located where it is, we can eliminate the water seperator which on your truck would be mounted on the fire wall right in the corner where the fender meets it.
There will be a pull ring right on the top that you pull up to drain the water and a fuel line going in and one out. There is also a drain hose attached to the bottom.

My next thing would be how much fuel is in the tank you are driving on?
Fuel pick up tubes are known to break off or crack.
When this happens, you can run out of fuel even though you have plenty of fuel in the tank.

Where it starts sucking air is between 1/4 and 3/4 of a tank, but usually below 1/2 on most trucks.
So next does it run fine when the fuel level is close to full?

The returns leaking may have been where the fuel around injector #2 was coming from, but again the electric pump should have eliminated the air intrusion problem once the engine was started.
Since you have the kit, replace all of the injector return lines and all of the O rings under the return caps, that can make cold starts much easier.

The mechanical lift pump would be located on the passenger side of the engine, the fuel filter supply line runs straight down to the mechanical lift pump, then back to the fuel tanks.

Yes, that valve under the drivers seat mounted on the frame is the tank selector valve.
Right now reading what you have posted since last night, the tank pick up tubes are the most logical place for your problem to be.

Any chance you are making oil?
The stock mechanical lift pump should be taken out of the fuel lines when an electric pump is installed.
If the diaphram in the mechanical pump ruptures you will fill the crank case with fuel, which can cost you an engine.

 

After I get the return line kit put in, and #2 injectors copper
ring fished out and its threads cleaned out I will go and
get some more diesel..and fill it up. Right now it appears to
be picking up because fuel runs out of the flexible line
connection at the fuel filter when I disconnect it with the
switch on. I dont feel that I'm making oil, but I wouldn't
have noticed it before I replaced the rear main, and I haven't
driven it that much since....only 165 miles. I will check, but I
do believe the mechanical pickup is bypassed. Thanks for
your input. I'll give you an update tomorrow.

 

Just a couple of thoughts. on my 87, i have a fuel issues that i have just had to learn to deal with until i can afford to fix them.

1. Like they have said already, the pick up tubes can cause an issue. On my Front tank, if i run it until it runs out of fuel the next fill up is only around 13 gallons. using the electric pump on my truck it will run a little farther, i am guessing from the constant suction of the elec pump picks up the sloshing and suck while driving.

2. My tank selector valve will change tanks on its own. It will read front tank and draw off the rear, hence, why i ran out of fuel this past week . If selected to the rear tank, all is fine and dandy, no change over problems while on rear, just on front. Even though the tank display shows what you have selected, with these being 20+ years old, it does not always mean that is where the valve itself is set. With the key on and engine off, try changing the tanks and listen to the valve and see if you can hear it change. Sitting in the drivers seat you can hear it change, try changing a few times and see how it sounds...

Just my .02$

 

I'll get my son to listen for me. I dont hear so well. Today I filled lup the rear tank till I could see
the fuel. Then I took off the old fuel filter, poured a little stanadyne fuel treatment and a little
diesel and put it on. I now have the backflow all back together except for the one flexible tube
that connects to the filter output. I turn on the switch and watch fuel come out of it. I hook it back up
and loosen the injector top connectors and turn the switch on for a bit, then I crank the engine
over several times and wait and turn it over several more times and dont see that it is getting
fuel to the injectors(i had loosened #1 and #2). I pour a little diesel in the air intake and crank
it and it acts like it wants to start but doesn't. If it is pumbing diesel fuel out and by the fuel
filter, but not coming out of the lines at #1 and #2 injector does it not sound like injector pump
problems?

 

when mine ran out this past week, i loosened up 1,2,3,4 @ the top of the injectors, ran the batteries all the way down, and then put another diesel to it, and ran jumper cables from each of his batteries to both of mine. Gave it a few minutes to boost up the charge and still took several minutes before i got fuel to the top of the injectors. I would say to try that... Put another vehicle to it to keep the charge up, and loosen the nuts on the front 4. and try it for a little while. but keep in mind to give the starter a good rest while doing so. it will keep from ruining the starter and help keep your batteries hot. Dont give up, these ol workhorses can have a mind of their own, they do what they want when they want...

 

I will crank away at it some more with 1,2,3 &4 loosened then and see if it wont start for me.

 

With the electric pump it should not take that much cranking with the injection lines loose.



With the key on, remove the fuel shut off solenoid wire (right front wire looking from the front of the engine) and see if you have power on it.
If you do, when you touch it to the FSS (fuel shut odd solenoid) terminal can you hear it clicking?

 

I have 12 volts there and it does click when touching it to
the clip.

 

Dave Spanaugh, I checked the injector pupm fuel stop connection and it has 12 volts there. With the
switch on and touching the plug to its connection I can hear a clicking. I have injectors 1,2,7 & 8
nuts loosened and after cranking a lots, no fuel shows up there. When I disconncet the flex hose
at the filter, it has a lot of pressure and squirts fuel on the inside of the hood pretty strong. Even
with the switch off and I disconnect the flex hose at the filter it has pressure built up and squirts
out hard.

Mariana 2003..I installed a new electric fuel pump and a new fuel filter and it pushes fuel pretty
strong, but not getting any to the injectors.

bpainting..Prior to installing the new fuel filter I put some stanadyne fuel conditioner in it with some
diesel fuel on top of it, still nothing after cranking a lot and letting it set overnight and cranking
a lot today.

Dave, is there anything else that you can think of that I can eliminate before getting the
new or rebuilt injector pump?

 

No it is starting to sound like either the IP has died or the govenor linkages are stuck.

And it the linkages are stuck that bad, a new IP is probable the way to go.

There is a screen inside the IP right inside the fuel inlet, but I can't get the diagram I have posted on the forum.