Stubborn 4.248 with low compression

[jjgurley]

I have an MF275 w/ 4.248 that ran five years ago, but sat in a field since then. I've replaced the lift pump, filter, and rebuilt the CAV, and I have 200psi in all cylinders (after adding a bit of oil to each cylinder). All injectors pop at 2250psi. Just about gave up trying to get it to start, when I found the block heater plug, and on a warmer day this Spring (about 75F) it surprised the heck out of me by actually starting, after daily attempts for several weeks. It took a bit of ether, as well. Not having topped up the oil, coolant, etc. I turned it off after about 15 seconds, although it seemed to be running fine.

Since then, I've tried daily for most of a month trying to duplicate the event to no avail.

[b:418a7da143]Are there any old tricks to get these things to start with such bad compression? [/b:418a7da143] I feel like if I can get it to run awhile, the rings might loosen up and the compression might improve.

When I try to start it, I do get grey smoke out the exhaust.

I've tried supplying hot intake air from a heat gun, higher flow air from a shop vac, and even tried pouring a little oil into the intake manifold (going into the injectors is really painful since you have to dismantle the fuel system).

 

[Dieseltech]

If some clown used a lot of ether you probably already have broken rings AND piston ring lands. Your compression is MUCH too low for any hope of a decent starting attempt. When that engine is RIGHT they start quickly..

 

[jjgurley]

(quoted from post at 19:17:57 04/22/20) If some clown used a lot of ether you probably already have broken rings AND piston ring lands. Your compression is MUCH too low for any hope of a decent starting attempt. When that engine is RIGHT they start quickly..

The problem is that some diesel guys have said it will never start, and others saying it should run at least a bit. I know it ran briefly, so I'm not sure who to believe. If there was a clown involved, it was probably me. I use ether routinely on my 580E and 450C with no issues. My neighbor ran heavy equipment for 45 years and always has a can in his truck.

 

[ptfarmer]

The piston rings can seize into the pistons after sitting for a few years. I'm working on a MF240 with the Perkins ad3.152 with the same problem after it say for 15 years or so. The rings are stuck in the pistons from the engine not being run!

 

[jjgurley]

(quoted from post at 20:16:19 04/22/20) The piston rings can seize into the pistons after sitting for a few years. I'm working on a MF240 with the Perkins ad3.152 with the same problem after it say for 15 years or so. The rings are stuck in the pistons from the engine not being run!

It finally got warm and I finally got the energy to address my tractor again. I tried to duplicate the conditions where it ran briefly last summer, so I injected about 20cc of oil into all pistons (via pulling the injectors). After putting it back together it was actually like it was nearly hydro-locked (which I could believe), but did turn over although the battery went pretty quick (and the starter got warm). Waited a few hours for re-charging, and with a bit of ether, it started right up. Not surprisingly, it needed a bit more ether to keep running as the injectors re-filled with fuel, at which time it ran great for about an hour at mid-throttle.

Closing the throttle slowed it down, but re-opening the throttle had a very delayed response. My throttle lever was really stiff, so I shut it off and called it a day.

Today, I dismantled the lever, cleaned up the friction components, and again, it started right up, again with a light whiff of either. It took maybe 10 seconds to run without help, but settled right down. This time however, when I closed the throttle, re-opening didn't accomplish anything. The lever on the injector pump is moving, so it's not the linkage.

I'm guessing I must have some loose connections in the injector pump output lines that are causing the inability to run immediately. The failure to respond to the throttle is weirder, since the half-throttle running verifies the fuel supply and needle valve. I'm looking for hints.

I know that ether is bad, but the alternative is selling this thing as scrap metal.

 

[ptfarmer]

(quoted from post at 15:01:05 04/08/21)

(quoted from post at 20:16:19 04/22/20) The piston rings can seize into the pistons after sitting for a few years. I'm working on a MF240 with the Perkins ad3.152 with the same problem after it say for 15 years or so. The rings are stuck in the pistons from the engine not being run!

It finally got warm and I finally got the energy to address my tractor again. I tried to duplicate the conditions where it ran briefly last summer, so I injected about 20cc of oil into all pistons (via pulling the injectors). After putting it back together it was actually like it was nearly hydro-locked (which I could believe), but did turn over although the battery went pretty quick (and the starter got warm). Waited a few hours for re-charging, and with a bit of ether, it started right up. Not surprisingly, it needed a bit more ether to keep running as the injectors re-filled with fuel, at which time it ran great for about an hour at mid-throttle.

Closing the throttle slowed it down, but re-opening the throttle had a very delayed response. My throttle lever was really stiff, so I shut it off and called it a day.

Today, I dismantled the lever, cleaned up the friction components, and again, it started right up, again with a light whiff of either. It took maybe 10 seconds to run without help, but settled right down. This time however, when I closed the throttle, re-opening didn't accomplish anything. The lever on the injector pump is moving, so it's not the linkage.

I'm guessing I must have some loose connections in the injector pump output lines that are causing the inability to run immediately. The failure to respond to the throttle is weirder, since the half-throttle running verifies the fuel supply and needle valve. I'm looking for hints.

I know that ether is bad, but the alternative is selling this thing as scrap metal.

Sounds like the linkage, or the weights inside the injector pump are probably siezed, sticking. Sounds like time to have the injector pump rebuilt.

 

[ptfarmer]

Like dieseltech said a rebuild would be a good idea also. The rebuild kits are quite cheap, and they aren't that hard to rebuild.

 

[jjgurley]

(quoted from post at 09:39:52 04/09/21) Like dieseltech said a rebuild would be a good idea also. The rebuild kits are quite cheap, and they aren't that hard to rebuild.

I rebuilt the CAV to get where I am. It was completely filled with goo from sitting with water filled diesel for 5-10 years. Getting the CAV out of the machine is a pain, so I'm hoping that's not the issue.