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Posted

Picked up a ud14a a few weeks ago. Engine was overhauled 30years ago and never used. It was sitting in a building with the exhaust covered when i picked it up. Cant get it loose. I poured 50/50 mix of acetone and transmission oil in the cylinders. Anyone have any suggestions on breaking it loose. I took the rocker arms off and blew air in the cylinders to try and push the oil down around the rings. Thanks 

Posted

I agree with removing the starter to try and bar the engine over and hopefully easily.

This will put a great deal of pressure on the engine to turn.

If you cannot get it to move this way, then quit wasting time and remove the heads.

Then you can see where the problem is and how bad it is.

Take it from a guy that has used a lot of time and every concoction known to man to get rust to turn to liquid. 

If bad it will not magically get better.

Rust is like cancer and it protects itself.

Posted

I pulled the starter and tried barring over the engine with no luck. That was the first thing i did. I guess i just let it sit for awhile and see what happens. 

Posted

If this engine  was indeed rebuilt  and never  used,  I  would  certainly  not use the popular  soak, hammer and pry method,which rarely works  anyway.

Unless all the cylinders  are stuck,  you have the rare opportunity to to have an engine  containing a majority  of new parts that are unobtainable.... be lucky  find a gasket set. You need to carefully  disassemble  this thing until  you  find  the stuck  part and approach it with surgical  precision 

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Posted

If it was never run even the gaskets maybe salvaged, KOO says carb cleaner never failed him to free and engine, are you sure your concoction got into each cylinder?

Posted

Is it a primer operated from the firewall?

Been a long time but that looks vaguely familiar to a UD14A that I got that had a jethead

  • Thanks 1
  • 3 weeks later...
Posted

The engine finally broke loose today. Tomorrow i will start going through the fuel system and give the mag a once over.   Im hoping to get it running this week. Is there anything i should check Before i try to start it? Ive never messed with a gas start diesel before. 

  • Like 2
Posted

Did you have the valve cover off?

I would check and make sure all the intake/exhaust valves move freely. There are also smaller starting valves in there too that need to move freely for it to switch over to diesel.

Your rack in your injection pump is probably also seized up and is a good thing to check. This is fairly easy to fix. Start by disconnecting the throttle control at the top of the injection pump control lever. Take off the oil fill tube on the injection pump. Inside you will see the fuel rack to the right (engine side) of the injection pump (circled in blue, not my picture). Take a screwdriver or punch and lightly work that rack back and forth. You can use solvent or WD40/PB Blaster, but very little at a time. Patience is key. The pump rack should be unstuck when the injection pump lever moves freely, and the rack inside moves freely.

Good luck!

MD pump.jpg

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  • 4 weeks later...
Posted

So ive been working a little more on the engine. I was able to get it running on the gas side and the t seems to run really well on gas. I was having some trouble with the diesel side and found a stuck scavenging valve. The tappet is cracked and the valve is stick in the valve body. Any idea where i could get a new scavenging valve assembly? It is an IH injection pump. Thanks 

  • 2 weeks later...
Posted
On 6/12/2026 at 9:49 AM, Powered by IH said:

Did you have the valve cover off?

I would check and make sure all the intake/exhaust valves move freely. There are also smaller starting valves in there too that need to move freely for it to switch over to diesel.

Your rack in your injection pump is probably also seized up and is a good thing to check. This is fairly easy to fix. Start by disconnecting the throttle control at the top of the injection pump control lever. Take off the oil fill tube on the injection pump. Inside you will see the fuel rack to the right (engine side) of the injection pump (circled in blue, not my picture). Take a screwdriver or punch and lightly work that rack back and forth. You can use solvent or WD40/PB Blaster, but very little at a time. Patience is key. The pump rack should be unstuck when the injection pump lever moves freely, and the rack inside moves freely.

Good luck!

MD pump.jpg

How far should the rack move. Currently the rack moves about 1/8 of an inch 

Posted
On 7/16/2026 at 7:01 PM, Lapowers said:

How far should the rack move. Currently the rack moves about 1/8 of an inch 

It should move more than that, here's how to fix it (my previous post):

On 6/12/2026 at 9:49 AM, Powered by IH said:

Start by disconnecting the throttle control at the top of the injection pump control lever. Take off the oil fill tube on the injection pump. Inside you will see the fuel rack to the right (engine side) of the injection pump (circled in blue, not my picture). Take a screwdriver or punch and lightly work that rack back and forth. You can use solvent or WD40/PB Blaster, but very little at a time. Patience is key. The pump rack should be unstuck when the injection pump lever moves freely, and the rack inside moves freely.

Good luck!

MD pump.jpg

Posted

Thank you for the help.  i did end up getting the fuel rack loosened up. It does run on diesel now , but i don’t t think its running right. I thinK injector No1 is not popping off right. When i open the bleeder on No1 theres no difference in how it runs. If i open 2,3 or 4 the engine will start running rough.

 

anyone know how to pull the injector out ? 

Posted
15 hours ago, Lapowers said:

Thank you for the help.  i did end up getting the fuel rack loosened up. It does run on diesel now , but i don’t t think its running right. I thinK injector No1 is not popping off right. When i open the bleeder on No1 theres no difference in how it runs. If i open 2,3 or 4 the engine will start running rough.

 

anyone know how to pull the injector out ? 

If you crack the injector line do you get fuel pulsing out like the other lines?

Can you hear if it runs like that on the gas side too or just on diesel? Meaning if you pull the number 1 spark plug wire off and do the same test as you did on the diesel side, what will happen?

I wouldn't pull the injector out yet until you can figure out that's your problem. Hate to do that and that's not your problem.

Posted
On 7/23/2026 at 1:27 PM, Powered by IH said:

If you crack the injector line do you get fuel pulsing out like the other lines?

Can you hear if it runs like that on the gas side too or just on diesel? Meaning if you pull the number 1 spark plug wire off and do the same test as you did on the diesel side, what will happen?

I wouldn't pull the injector out yet until you can figure out that's your problem. Hate to do that and that's not your problem.

The engine runs good on gas. I pulled the No1 injector and it was not opening up. No fuel was coming out of it.  Took it apart and cleaned it now its working except the engine is smoking. If i open the bleeder the smoke stops. Maybe if i let it run for a couple hours it will clean up.  Or i will hunt up another injector. Thanks for the help. 

Posted

Something to think about. The injection pump is positive displacement. It is obviously bled out because it is running on the rest of the cylinders. Where do you think the fuel went when it could not get out that nozzle?

Posted
15 hours ago, Lapowers said:

The engine runs good on gas. I pulled the No1 injector and it was not opening up. No fuel was coming out of it.  Took it apart and cleaned it now its working except the engine is smoking. If i open the bleeder the smoke stops. Maybe if i let it run for a couple hours it will clean up.  Or i will hunt up another injector. Thanks for the help. 

You could try running it for a while, varying the speed and load if you can do that. You could also dump some diesel fuel lubricant in the tank too (like Stanadyne Lubricity Formula) and see if that makes any difference.

Ultimately if that doesn't fix it you need to pull the injector and pop test it to figure out what's going on. It will tell you if you injector is leaking and needs to get fixed, or if the opening pressure just needs to get bumped up again if it's low.

Another possibility is switching the #1 injector around with another one to make sure it's the injector and not the pump. Just a thought.

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