I am in the process of getting things buttoned up, but I have an issue. I decided to go ahead and try to start the engine before I got everything else done. I started trying to purge the fuel lines. I pumped and cranked for days. It seemed I was getting nowhere. I installed an electric booster pump, looking for help. I replaced the lift pump. I kept cranking and pumping and finally got fuel at the injectors. For a while only three of the injectors got fuel After much cursing, burning up 2 starters, I finally got fuel flow at all the injectors. I rigged up a switch and solenoid for the glow plugs, and for a while could get some sporadic firing, till finally she caught and ran.... for about 15 seconds. This is where I am now. I can only get the engine to run for a few seconds at a time. There have been instances where I can start and run several times in a row, then nothing and I'm back to cranking and pumping. I'm not seeing any air in the lines, but I'm thinking that's the problem. I did find a small crease on the line from the lift pump to the filter, and I replaced it. Sometimes it will run for about 30 seconds, long enough to give it a few revs and come back to idle, then she peters out. I am stumped here, but I know someone out there has the answer.

COME ON GUYS, BAIL ME OUT HERE!

 

keep checking for air leaks ,,, fuel returns. Also I am HUGE fan of Seafoam Hot soak treatment method on the MB617. especially if the engine was sitting for a long time. Plus it will give you a chance to open up the fuel filter and replace if possible.
Have your run well on a remote fuel system????

 

Has anyone messed with the timing chain or IP timing? Anyone messed with the IP internals? I would run a line straight down to a tank on the floor to eliminate all sources, bypass everything but the lift pump, same goes for the return. I bet the problem #1 restricted pickup in the tank, #2 pickup and or return line to small.

 

The Fuel tank pick up is all new, fabbed by myself. The tank was cleaned out before re-install. I ran all new 5/16 fuel lines feed and return. Do you think I should use 3/8? Although I am a neophyte when it comes to diesel engines, the first things I thought of were : possible air leak that I can't see; fuel delivery problem. I did remove the head for some clean up, but kept the timing correct (timing marks on the cam and crank). As I said before when it starts and runs, it seems to be running pretty good, such that I think the timing may be ok (maybe not perfect, but ok). Should I have one of those cigar hoses on the return?

 

The fuel filters are new, as are the fuel supply and return lines. I have not tried a remote tank on this engine since I bought it. It ran on one sitting on my garage floor when I got the thing home. I am running 5/16 fuel/return lines. I will replace the other 2 hard plastic lines and see what happens.

 

I would go for the remote fuel supply and see if you have a engine or chassis problem? While you are in there you can add the seafoam to your filter canister and kill 2 birds with one stone.
did you check well for leaks at the injector fuel return lines the little braided ones that connect injector to injector? Also know problem areas are the lift pump seals.
Some people swear you need the cigar hose, I am doing fine without the cigar line.
years ago on a little perkins, I had to put a high loop in the injector return line as an air trap so I could limp home and replace the lines, you could just barely see the air bubbles coming up the line to the high spot.
are you pulling or pushing thru the primary filter?
the remote fuel tank should get you an answer

have fun

 

After trying as many things as I could think of to get this little booger running, I ran into a guy who is a complete fiend for the early 80's Merc diesels. Told him my issues, and he asked if I had ever checked the compression. I had not. He told me it sounded to him like I had bad compression on all cylinders and probably VERY bad compression on some. I tried to rationalize other things that could be the problem, and all he would say is "check the compression." I stalled around for 3 weeks, working on other things around the house, not wanting to find out what was probably going to be bad news. Then I checked the compression. The reading on the first cylinder was around 110. Had to be wrong. No, it was right! Second was 115ish, third was 112......I stopped checking. Sheesh. I now stand in front of the jeep from time to time, Makers Mark in hand, waiting for inspiration to hit motivate once again.

 

Think I'll check the compression again this weekend. If this proves to be crap for compression, the next question is do I try to fix this motor, or buy a new donor? anyone? anyone? What's the answer?

 

what I would NOT do; is spend thousands $ on a full rebuild for a motor/trans combo that you don't even know if you like driving. did you ever try running on a remote fuel tank???????????
Is there any chance you can do a differential compression test or charge the exh and intake with compressed air to see if you have valve or ring problems?
Did you try all the bad things to do to a engine to try and raise compression? soak cylinders for a few days in something? stake and lap valves? check compression with fresh oily wet cylinders.
you might get by with not a full rebuild, just rings or valves

 

the remote fuel tank didn't change anything. I had the head off and lapped the valves, they looked ok to me. the valve guides and seals were replaced. I was checking compression through the glow plug hole, should I have used the injector hole instead? If I were to "soak the cylinders" should I pull the head off, or just remove the injectors. Then how do I get all that crap out of the cylinder? What do people generally use for soaking? Does a wet compression test tell me the rings are bad? I don't have a differential compression tool, don't even know where to get/rent/borrow one, but that would be a great test.