Hey, I just wanted to run this by the forum, make sure I'm doing the right thing, checking to see if my IP is dead. I have a no start condition.

I pulled the banjo into the IP and cranked, fuel comes out. I reconnected that, pushed the primer button a little, then disconnected the forwardmost injector line...thde fitting took a 19mm wrench and was right above the knurled fitting (DV?). When I cranked it, no fuel shot out.

Is it safe to say the IP is shot?

PO told me this is a fairly new pump rebuilt by Marty @ Precision Diesel.

Here's some background on my truck an this no start problem...
https://www.dieseltruckresource.com/...d.php?t=121837

 

I would not go there 1st , the p7100 are so relible , that I would look at fuel pressure , lift pump , overflow valve , 1st , the liftpump can push some fuel but not enough to run , the overflow valve is what make pressure by restricking the return , so if it not right that could also keep from running .

 

Sounds as the fuel shut off solenoid is not working.

Turn the key on, but don't crank. Go under the hood and see if the linkage will lift and lock in place. If that's a go, then go crank it.

 

I had a no start condition on my 1994. It was the Fuel Overflow Valve on the injector pump. Take it out, take it apart and measure the spring. It should be .50.

Mine was .45 or something like that. I stretched the spring out and reinstalled. It's a tapered spring so remember to put the taper toward the check ball or the ball will be pushed into the spring a let fuel bypass back to the tank.

Truck ran like a champ after that so I ordered a new Overflow Valve from TST. It takes off now.

 

Highly doubt your pump is shot, but you probably have air in the system. After you check that the solenoid is pulling all the way up loosen 3 injector lines at the injector and crank till bubble free fuel appears. Tighten them back up and it should start but run rough for a few seconds.

 

Done that, solenoid holds up.
Then I had the wife come out and crank it. The solenoid pulls up by itself during cranking.

 

Loosening one line at the injection pump is no good? How about 3 at the injection pump, or do I need to go to the injectors?

I'm making a mental plan of what I need to do tommorow. I'll check the overflow valve spring too.

I don't have the equipment to check FP yet. Where does everyone measure FP, a tapped banjo on the IP inlet? What sort of pressures should I be seeing on a 12V?

 

Lots of time loosening at the pump doesn't work.
What happens is air in the injection lines compresses rather than building enough pressure to pop open the injectors. A never ending cycle can develop without the engine ever venting air and starting.

Tapped IP banjo is the way to go for FP. You should see about 18-22 at idle and 25-35 at full throttle no load. You must use a dampener or needle valve opened just a crack in the line to the gauge or the needle will pulsate so wildly in the few seconds before it self destructs that you won't be able to read it.

Needle valve installed on banjo bolt

 

Hmmm, my the spring in my overflow valve sounds a lot different. It measured 0.680" long and wasnt tapered at all, 0.240" diameter on both ends.
I didn't know what else to check in there, just found a ball and spring, other that the above discrepancy, everything else looked OK...?

I cracked the front 3 injector lines, no fuel came out at all during cranking. In hindsight, maybe I should have seen if the IP was pumping air thru it.

Then I loosened the overflow valve again and cranked it. Fuel came spurting out.

I have yet to put a gauge on it, but it seems there is some fuel coming into the IP and none coming out.

I found a tapped banjo bolt in the garage, but I don't have a FP gauge. Should I be seeing 18-22psi during cranking?

 

If you crank it long enough you should see around 20 psi.
You checked that the shutdown solenoid is lifting all the way up?

 

How do I know if the solenoid is going all the way up?

I took it off and it looked OK, cleaned/lubed it up, tossed the remains of the oil-soaked rubber boot and replaced it with a section of bike tube.

When the key is switched to on, I can lift the solenoid up a little and it gets 'sucked' up the rest of the way, not sure if its 'all the way up'. It feels solid when it gets pulled up, I can't budge it. I had my wife crank it, and it pulls up automatically when the key is turned all the way, then it drops down when released, after a no start.

 

As long as you are getting NOTHING out of the lines at the injector when you crank for an extended time. This is just an idea, check over the linkage on the shutdown solenoid. After I installed my GSK kit I lost the key to shaft which the shutdown solenoid was connected to via a the bracket. I had to play with it to get it back in the right spot. Perhaps the clamp around the shaft is loose and the key fell out, not allowing the rack to shift into the start position?

 

I should have read the link from your run away earlier. That pointed to a classic stuck rack.
Has it been running since last fall?

 

"stuck rack"...is that the external linkage or internal to the IP, more details please.

No it hasnt run at all since the incident in the fall. <insert lame excuse here>

There is NOTHING coming out of the front three injector lines at the injector.

 

Fueling Around makes a good point, I also didn't read your link right away. The rack is what controls the amount of fuel delivered. When you shut your truck down, the shutoff solenoid shifts the rack into a position that "vents" the fuel to the bypass ports so no pressure gets to the injectors. When you go to start it it shifts the rack back into the run position and closes off this "vent" (actually called helix) so all fuel pressure goes to the injector. The rack is all internal. Sounds like the pump's got to come off of there. I don't know any way to fix a stuck rack externally, hopefully someone on here may have a better idea. Good Luck!