M923a2 problem

[NJDEUCE]

Hi, I need to bounce a problem I am having off of everyone. When my M923a2 is cold, it starts right up like a top. After I drive it and warm it up, then shut it off, it gives me a really hard time starting...sometimes so hard I can't get it to. I'm not sure where this problem lies. Could it be a fuel issue? I would think that would make it hard to start even when cold. I'm leaning more to an oil issue, because I know oil thins as it gets hot. I am hoping someone has had this issue and resolved it and can give me some advice. It's a really frustrating issue, the truck runs beautifully, but God forbid I want to stop somewhere I have to leave it running or wait for it to cool down. Thanks for any advice guys!

 

[Artisan]

Open TM 9-2320-272-23-1 /
FIELD MAINTENANCE


ENGINE CRANKS BUT DOES NOT START
Go to PDF page 287 and start the process. PS, Don't listen to me, but I would start there...

 

[PSturg66]

Perhaps loosing the prime?

 

[1 Patriot-of-many]

Most likely not your problem(since yours only happens when it's warm) but mine has a starting issue once in a while,the fuel shutoff valve on the injector pump hangs up on the shut off cable, not always snapping full forward. A little marvel mystery oil seems to fix it for a few months.

 

[Rifleman]

In order for your engine to start you need three things, fuel, air and a spark. I would do as Artisan said and read the manual, the military spent alot of money having these manuals written. They are updated every few years with new info. covering any new issues or problems that have come up since the last volume was written. So i think any problem your having will be covered in the manual along with the correct solution.

 

[Derrickl112]

.

 

[Rifleman]

Derrickl112, when i was talking about the three things needed for the engine to run (Air, Fuel and spark) this is what i meant. In some cases spark in a Diesel engines is a glow plug to start the combustion cycle, in other Diesel engines spark is a high enough compression ratio to start and sustain combustion once fuel is added. I now hope my "spark" comment makes more sense to you.

 

[wheelspinner]

Is it cranking but not firing, or not cranking or cranking hard? These are two completely different scenarios. I ask because I'm not really sure where the oil question comes from?

If its cranking hard when warm, most likely will be 1) weak starter-electric motors work better when cold, or 2) corroded ground-electric motors current demand increase when they are warm. Both of these conditions would create hard cranking when the engine is warm. Has nothing to do with oil if you have enough oil in the engine.

 

[NJDEUCE]

It is cranking but not firing. It cranks fine. If it isn't really hot, like after a short drive, I can get it to fire after three or four long cranks. If its after a long drive and the engine is really warmed up, it will crank and crank and then it will fire and die. It sounds like a fuel issue I know. I only mentioned oil, because when it gets hot the viscosity changes and it gets thinner making it harder to compress right?

 

[wheelspinner]

Give this a try

TM-9-2320-272-23-1-Field-Maintenance-Manual-2012

Conduct these malfunction tests if engine fails to start. This procedure will check for theemergency engine stop control not correctly set, air in fuel system, coolant in combustionchambers, loose fuel supply line connections or fuel supply line at fuel filter head, leaking ordamaged primary fuel filter, contaminated fuel, low fuel supply or vacuum pressure, and anempty ether cylinder. It also checks for a faulty fuel transfer pump, fuel supply line, startercircuit, fuel filter, ether start system, thermal close valve, and ether atomizer. In addition, thisprocedure checks for a clogged or dirty air intake stack, air cleaner element, fuel injector​

supply line, fuel filter, fuel pump filter, thermal close valve tubing, and atomizer tubing.

Here is the TM ref, and the narrative for what its checking. Way too much for here.

Also you are not compressing the oil, oil is a lubricant. In a diesel if you are compressing oil, that will give you a runaway engine as it will consume the engine oil. That is bad.

 

[NJDEUCE]

Thanks I did read through that last night, and I will go through it, was just hoping someone had this specific problem before and could help.