The Universal M25 is winning the battle

[donradcliffe]

I am usually pretty good with diesels, but I have been unable to get a friend's M25 to run in her 1983 Catalina 30.

The fuel gauge reads half full, the batteries are on the shore charger and the starter cranks the engine well, the glow plugs were suspect, but I have replaced the two easiest ones, and the glow plug circuit draws 25 amps.

It turns over, then sounds like it is catching, but just doesn't accelerate into running. I have let it turn with the starter helping for 10 seconds, but it just dies when I stop pushing the starter button.

It helps to hold the glow plugs on for longer times, but up to a minute and still no joy. I even hot wired them on an external battery to no effect.

The electric fuel pump is clicking when I turn on the ignition.

I have cracked injector lines and they spurt fuel when cranking. There doesn't seem to be any different response when cracking different cylinders.

The engine was hard to start cold 5 weeks ago, but ran smoothly and started hot which no glow plugs. It did die when I throttled it all the way back, but I adjusted the low speed stop and that solved that problem.

I loosened the wire to the kill lever and ensured that it was in the off position.

I squirted WD40 in the intake when it was cranking to no avail.

And yes, I closed the thru hull after the first 15 seconds of cranking.

I have eliminated a bunch of culprits, but I am down to a stuck rack in the injection pump or water in the fuel. Access is terrible and the IP will be a bear to remove.

I am tempted to use a shot of quick start to verify the the problem is fuel, and perhaps shake the IP rack loose.

I am also considering replacing both fuel filters and bleeding the hell out it, but access is terrible. There should be a bleed valve on the engine, but I have not found it yet.

I was even considering going to church today, but I have a race, so it will have to be the Church of the leeward Mark.

What would you suggest??

[sailormed]

Run of a jerrycan of new good fuel directly to engine fuel filter to eliminate the fuel and primary fuel filter as being the cause.

[Stu Jackson]

Originally Posted by sailormed

Run of a jerrycan of new good fuel directly to engine fuel filter to eliminate the fuel and primary fuel filter as being the cause.

Good idea.


Also this:


Fuel Starvation and The Obscure Check Ball Valve
https://c34.org/bbs/index.php/topic,10681.0.html
and
https://forums.sailboatowners.com/th...l%20Starvation


Also, what position is the Knurled Knob on the input to the injector rack? I keep mine closed except for cracking it when bleeding. There should never be a reason to crack injectors on this engine because of that knurled knob.


Also:


Engines 101 - The BIGGEST & BEST collection of M25 Series Universal Engine Information on the Internet, plus some M35, too This includes a link to the Critical Upgrades topic which has more engine information please read it too.

http://www.c34.org/wiki/index.php?title=Diesel_Engine

[Tetepare]

If it’s been cranked a lot the muffler will fill with water and it won’t start. Drain the muffler.

[tkeithlu]

Stu, thanks so much for posting that link to the M25 info. I have one on our genset, and have never seen guidance that good.

[contrail]

Originally Posted by Tetepare

If it’s been cranked a lot the muffler will fill with water and it won’t start. Drain the muffler.

Uh, he said he closed the seacock after fifteen seconds.

[Simi 60]

So it's a Kubota d850.

[Ballsnall]

3 suggestions,

Air in the fuel system.
Blocked exhaust.
Engine under load.

[Tetepare]

Originally Posted by contrail

Uh, he said he closed the seacock after fifteen seconds.

Uh, I can read.


And before that?

It takes one minute to drain the muffler and eliminate that problem.

[sinnerman]

Dumb question, but could the decompression lever be in the "down/actuated" position ??

[captlloyd]

Originally Posted by Ballsnall

3 suggestions,

Air in the fuel system.
Blocked exhaust.
Engine under load.

Air in the system would be high on my list of probabilities.

[Lepke]

If you have fuel squirting when you slack the injector nuts, then it's probably not a fuel issue. But maybe an internal injector pump problem. Governor or timing.
The injector tips can build deposits blocking some or all the spray holes. Old, unused injectors can have the needle valve stick. Organisms that grow in diesel can happen anywhere in a system that has sat for a long time. If they happen after or in the secondary filter organisms can plug the injector tips.

Ether in small amounts, won't hurt an engine. Don't try to run on ether. Some engines are started every day for decades using ether.

[Ballsnall]

Originally Posted by Tetepare

It takes one minute to drain the muffler and eliminate that problem.

That would be my first check as well.

[Madehn]

Spray wd40 in the intake while cranking. If it fired or runs briefly you have a fuel issue. If it doesn’t perhaps you have a compression issue.

[Quadrille in JB]

My M25 will not start on WD-40. When it’s cold it won’t start unless the glow plugs have been held in for at least 20 seconds. It acts exactly like the OP described. It sounds like the glow plugs are working from the amp draw so my best bet is bleed the injectors, thoroughly. And make sure you use the glow plugs before each starting attempt. I’ve had the same problem After replacing my fuel filters.