No Fuel to Injectors

DowneyB

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Long time lurker, but I finally have a problem I cannot figure out.

I drove my truck last Tuesday evening, started and ran fine even though it was like 10 degrees out. Wednesday morning, same temperature, it will not start. I have determined over the last two evenings that when I crack injector lines, I do not get any fuel when cranking at the injectors. Up until this point, this has been the best starting and running idi I have ever had.

Everything else checks out. Fairly new Group 31s, okay battery cables, and a pmgr starter so it spins really well. I have an electric fuel pump, a new filter, and there was no gelling anywhere Wednesday evening or Thursday evening after work when I was working on it. (It was a balmy 32 degrees out, and I'm working in the driveway.) I took the top off the IP and checked that the fuel shutoff solenoid is working correctly, and the input side of the shaft inside the pump is turning. If I loosen the return line on the top of the pump while the lift pump is on I get a lot of fuel coming out of it. (GPs appear to be working, but with no fuel that doesn't really matter yet)

At this point I still don't know what is actually wrong, and I'm out of ideas on how to figure it out. Is there something I'm missing in the IP that I can check? How can I tell for sure if the pump is shot or not? I can't afford to just throw money at it, so I'd like to have a good confirmation of what is actually wrong.
 

IDIBRONCO

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To have a pump just quit overnight when it was working the previous evening doesn't sound right. I would still suspect gelling. Mine gelled on me last Tuesday. It started up normally in the afternoon and idled for 5-10 minutes before gelling. Did it get colder than 10* and then warm back up?
 

franklin2

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Disconnect the glowplugs and give it shot of ether and see if tries to start.
 

DowneyB

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The overnight thing is why I'm so confused. I got down to maybe 5 degrees that night. But it got up to above freezing the next two days and I still couldn't get anything out of it. I suspected gelling, so I put a heat gun on the IP and let it sit there for 15-20 minutes so the whole thing was heat soaked and I still nothing. What are the odds that some small spec has gotten in the wrong place(s) and plugged it up? And is there a way to fix that?

I've had problems with glow plugs before, so when it didn't start I tried starting fluid first, then when it didn't start I cracked an injector line and figured out that the injectors weren't putting out any fuel.
 

Nero

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Just for kicks... Do you have power at the shutoff solenoid when the key is on? Checking the FSS doesn't mean it's getting power. I've had the fusible link for the FSS burn up on me before. Kinda fun to drive around with a jumper cable on the IP from the battery.
 

IDIBRONCO

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I suspected gelling, so I put a heat gun on the IP and let it sit there for 15-20 minutes so the whole thing was heat soaked and I still nothing.
From my two experiences, it seems like the fuel lines along the frame gel up first. They are lower and are more exposed to wind than the IP is. Also, unless they've been replaced, part of them are steel which will conduct heat/cold first and better than plastic will.
For me, this last time, the fuel in the filter was just fine. The engine just ran out of fuel.
The first time, it was around 0* with a north northwest wind that was blowing about 30 MPH. I had driven over an hour north, parked at Menards for an hour os so, then I went to Wal-Mart for about another hour. I knew that I should have left the engine idling, but the parking lot was sloped pretty good and I don't know whether or not my parking brake works. The same thing happened then. I started the engine and it started fine, idled for a short time, and then quit running as I was trying to leave. The engine was warm enough that it started without glow plugs and the heater was blowing warm air right away. Again, the fuel in the filter was fine. It just ran out of fuel to the engine.
What are the odds that some small spec has gotten in the wrong place(s) and plugged it up?
It's possible, but it would have had to happen right as the engine stopped running the night before. Impossible? No, but extremely unlikely in my opinion.
 

franklin2

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It would not start with ether? Ether skips it all, fuel and glow plugs. If the engine is sound, it should try to start on ether.
 

DowneyB

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Alright, just so I don't leave this unfinished:

It must have been something in the injection pump. I still don't know what it was, but it would not put fuel to the injectors. I swapped it out with a pump from an engine that threw a rod a little over a year ago. (I don't really have a good history on this pump, but it was in the truck and ran well enough) It bled easily, and once I tightened all the injector lines down it fired right up. I timed it to somewhere between 8 and 9 degrees and it has been running great the last few days.

It does idle a bit lower, and the rpms rise slowly through the first quarter or third of the throttle travel. And I need to re-adjust the vacuum modulator thing. And under the right circumstances I can get just the tiniest puff of black smoke now. But all in all, this seems to have solved it.
 
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