2.1L Diesel mj

[Muncher]

might buy a 2,1 diesel soon. it does not run but went and looked at it today and it does crank over pretty well. who on here knows enough about them that could give me some ideas on what could be making it not run? 

[eaglescout526]

The breakaway rocker arms that probably prevented catastrophic engine failure would. Bad fuel pump. Could be damn near anything that would keep a gas engine from running. Maybe a bad glow plug relay. Honestly who knows. 

[gogmorgo]

Did it quit and get parked, or has it just been sitting a while? If it quit before it was parked you’re likely looking at a mechanical issue. If it’s just been sitting forever it could be as simple as needing the fuel system primed and bled, or it’s gummed up from sitting and needs cleaned out.

Does it do anything while cranking? Sputter a bit? Smoke out of the exhaust?

[Muncher]

i think it ran and then just sat for a while. didnt have a good enough jump pack to crank it long enough to see smoke 

[Muncher]

4 hours ago, eaglescout526 said:

The breakaway rocker arms that probably prevented catastrophic engine failure would. Bad fuel pump. Could be damn near anything that would keep a gas engine from running. Maybe a bad glow plug relay. Honestly who knows. 

it does have new sleeves pistons and a new head 

[Agreen]

Mechanical injection is easy, but it has to be primed and free of air. Crack the lines at the head loose, crank it over until fuel comes out at each one, tighten, then try starting again.

[Muncher]

Alright once I get it I'll try that

[Pete M]

make sure there is new diesel in the tank and fuel lines. 

[Muncher]

Yeah I'm gonna assume the fuel lines are gelled up.

[pizzaman09]

Diesel doesn't age nearly as badly as gasoline.  That said the stuff in the lines is probably junk but the stuff in the tank will probably run the engine.  I helped someone resurrect an M1008 Army Chevy K30 pickup truck with the awful 6.5L Detroit Diesel.  It had been parked for 10 years due to a bad fuel pump.  With the pump replaced we could get it to start and run at wide open throttle.  After several minutes of it only running at WOT it started to idle and run perfectly on the diesel that was 10 year old in the tank.

[gogmorgo]

Maybe it's less of an issue in warmer climates, but if you leave it in the cold with summer fuel in the lines it can drop paraffins out of the fuel. Usually it's only an issue if it was run with the summer fuel, because it collects in filters and injector screens, but just sitting in the cold can sometimes be problematic. Had it happen to a tractor at work a few years back after it sat just one winter. When we went to look at it after they couldn't start it in the spring, the filter was plugged right full of wax.

But it's hard to diagnose an engine without much more to go on than it just cranks and won't start.

[pizzaman09]

On 11/23/2022 at 12:03 AM, gogmorgo said:

Maybe it's less of an issue in warmer climates, but if you leave it in the cold with summer fuel in the lines it can drop paraffins out of the fuel. Usually it's only an issue if it was run with the summer fuel, because it collects in filters and injector screens, but just sitting in the cold can sometimes be problematic. Had it happen to a tractor at work a few years back after it sat just one winter. When we went to look at it after they couldn't start it in the spring, the filter was plugged right full of wax.

But it's hard to diagnose an engine without much more to go on than it just cranks and won't start.

Indeed, the first thing we did was replace the filter, it was solid.

[Muncher]

Yeah as he said I've si worked on a big loader that only sat a couple months in the winter and the whole fuel system gelled up and we had to rebuild all of it. 

[JeepcoMJ]

Pm me and I’ll have you talk to my dad.  Probably not anyone on here who knows as much about them as he does

[acfortier]

Did you buy it? Cause if you don't, I'm extremely tempted to own one of these rare diesel MJs... 

[OldManComanche]

Has it ever been started since the new parts were installed? Why was this work done?? From the research I have done, if the timing belt fails then the pistons and valves come together causing BIG problems!!

You need a good strong cranking speed to start it! A GOOD battery!

You need good clean fuel squirting out of the injectors to start it!

Press the throttle to the floor and crank it. Any smoke from the exhaust? No smoke means No fuel or compression.

Loosen the line to one of the injectors and see if any fuel squirts out? No fuel means no start.

Does the cold start aid (glow plug) work?

What type of transmission, auto or manual? If it is a manual you can pull it in gear and see if you can get it to start.

Do NOT use starting fluid unless you know how to use it!!

It could be something really simple or something really bad!

 Good Luck

[OldManComanche]

I did a little more research on the 2.1 turbo diesel motor. Did the timing belt break and the pistons and valves get together? Is this the reason fro new pistons and head?

[Muncher]

Not sure on that. I belive it did run after the pistons were replaced. I saw while looking it's extremely common for the sleeves and head to crack if it overheats.

[Muncher]

On 12/8/2022 at 4:06 PM, acfortier said:

Did you buy it? Cause if you don't, I'm extremely tempted to own one of these rare diesel MJs... 

Not yet. Saving for it he's saving it for me.