I am at my wits end and pocketbook's end too. My 7.3 won't start since a long sit. I checked the solenoids and each clunked when powered up. I checked the solenoid lugs for power with the switch on. All had power. I checked the glow plugs. All were good and got power during the glow plug cycle. I then replaced the fuel filter. I primed the filter through the schrader port until fuel came back out. I checked the pressure at the schrader and got 6 psig cranking. I popped the schrader while cranking
and got what I would call decent flow. I then turned to the I/P.

I pulled a few injector nuts off and got no fuel from them. No pressure either. I decided the I/P must be bad. I put a new rebuilt I/P on. To be sure the I/P had a good prime, I removed the input fitting at the filter. I improvised a line from a squirt bottle (a lab wash bottle) and pressure fed one and one quarter quarts of new fuel into the I/P. I had to loosen the top cover on the I/P to get it to take the fuel. I tightened the cover and cranked the engine with all 8 nuts loose on the injectors. No flow and no pressure. The same problem I had with the old I/P.

I don't even want to think about a second bad I/P since I did a good job of Locktighting the 3 bolts holding the pump to the gear. The only thing I haven't tried is checking the voltage at the fuel cut off solenoid while cranking. As above, I did make sure it had voltage with the switch on.
I have to commute 35 miles round trip to a field where I am working on this thing each time I run the batteries down. I'm getting ready to sell this
damn truck for what ever someone will give me for it. Any ideas?

 

It seems to me that if your pumping fuel in thru the shrader valve somehow there would be no way for the air to get out. Try pulling the filter off and making sure it's full to the top. Was it running when you parked it or did it have problems then?

 

What are we working on, is it a standard tranny. I'm willing to bet it is not spinning fast enough for the Ip to pump. It has to spin something like 250 rpm,s, which means batteries, cables and starter has to be completely up to snuff. I have never seen anybody prime one through the schrader valve either, and would do as galute says,but if the pump is workinf and your starting system is working proprely it should self prime. If it is a standard I would pull start it.

 

Let me clarify about the priming. To fill the filter, I placed a fine tube smaller than the opening in the casting to fill the filter. The outflow came out around the small tube. This was done by removing the schrader fitting from the casting.

To prime the I/P I removed the inlet elbow from the filter casting. I then pushed fuel into the I/P through the filter using a barb fitting with a short hose. To relieve the back pressure, I had to loosen the cover on the I/P.

The truck is a stick shift. The field I am sitting in does not lend itself very well to pulling to start. This guy I rent from has a large quantitiy of vehicles parked all around and a crappy dirt road to exit.You exit onto a very busy main four lane road. Not impossible, but won't be fun. The engine does spin pretty well. I recharge the batteries by carrying them home each day. This may be a last resort though. This truck is a stake body truck and will need a formidable pulling vehicle too.

The truck started and ran perfectly until I parked it for several months while I reworked the brakes, the tranny mounted parking brake, and general lubing.

 

easiest way to fill the filter is to fill it with diesel or your choice of cleaner while its off and then screw it on.

 

How quiet is it where the truck is?

With the key on, remove the wire to the fuel shut off solenoid.



Now listen closely as you touch and remove power to that terminal.
You should hear a click from inside the IP which is the fuel shut off solenoid operating.

If you do not hear a click, do not start the engine or it may run away.

Two things jump out in this post.
First was loosing the IP cover, the shut off solenoid linkage may have unhooked when you did that.




Second is priming the pump that way, fuel would drain back out of the IP when you hooked the fuel line back up and it still has air in the IP.

The return line from the IP id the hose mounted on the top cover and it needs to be completely full of fuel to work correctly.

Last but not least, where did the new IP come from?

 

I have not checked the new I/P for clunk sounds from the solenoids but I will do that Monday when I go down to the truck again. The only good thing about this field I am renting a spot in is it's quite.

I barely cracked the seal on the cover of the I/P. Just enough to let it breath out since I was pushing fuel in. I did not loosen it enough for anything inside to move. You couldn't get a knife edge in the crack that I made to let the I/P breath.

The inlet of my fuel filter where I was pushing in the fuel is the highest point in the system. Unfortunately I ran out of the bucks worth of fuel I brought that I didn't get to overflow around the crack in the cover so I am not sure how much more fuel it would take to fill the system completely. I assumed that a quart plus a small jar of it would be more than enough when I started. I must not have gotten enough fuel in to fill the overflow hose since that sits above the cover which never was totally full. I guess I hoped cranking it would fill the last voids of air.

 

After 3 threads, much money and lots of work, I finally got
my engine where it will start every time. Once all fuel problems
were eliminated I was forced to move to the glow plug circuit. All
voltage drops looked good so I decided to follow a guy who
recomended changing the system to a push button to fire the relay.
While I was removing the controller to start the change to a push
button, I saw it. A one sixteenth inch crack from one post all
the way down to the base of the relay. A new relay and away it
went. One of my threads also contained a question on how to get
off the turn signal switch. I have it on my work bench now and it
is already fixed. I had to take it apart. There was a jambed
slider on one switch. All I have to do is reinstall it and away
I go.