Universal M-18 not starting

[Better_Angel]

This past Sunday I started the engine and spent some time on mooring cleaning bird poop off the cabin top.
Spent 15-30 minutes with the engine running normally at idle. Water was coming out the exhaust and the temp was fine.

After that time the engine stopped running and refused to restart. By now it was hot so I left it alone and went off to do other things.

Here is the setup:
Tank > Racor filter > Facet pump > 10 micron secondary filter > High-Pressure pump > Injectors > Fuel Return

I returned the next day. Drained the Racor and all is fine. The fuel was clean and the filter element was clean.
There was some junk on the Facet fuel pump but very minor.

1 - started to bleed the system. Engine Stop Lever (T-handle) was out because I was not looking for it to fire yet.

2 - the water intake was shut off to prevent the engine flooding.

2 - filled the Racor and the Facet electric lift-up pump ticked along normally.

3 - bled the 10 micron fuel filter at the back of the engine and all was fine.

4 - bled the high-pressure engine fuel pump where the fuel comes in (red in the picture below) and all was fine.

5 - loosened the lines that go from the pump to the injectors. Cranked the engine but nothing come out from either one (before the lines to the injectors - blue in the picture below).

It would appear that the engine fuel pump is dead.

Any way to verify this? A search for other threads with this problem did not pull up any other results.
It appears to not be a common problem, so is there something else that I'm missing?

Do I need to have the Engine Stop pushed in in order for the engine to create suction and prime the high-pressure pump?

How does that pump work? I haven't found any pictures of it other than the diagram I attached.
It looks like there is a cam turning below it, and it presses on the bottom of the pump, which looks like a little piston that goes up and down and pumps fuel.

I would vastly prefer for the pump not to be broken because they seem pricey: Marine Parts Supply has them listed for a mere $3,753

Thanks in advance for your collective wisdom,
Gabe

 

[Ralph Johnstone]

It would appear that the engine fuel pump is dead.

Is there any way to have someone crank the engine, stop cable in the run position and you very carefully unscrew a supply line at an injector to check for the injection of fuel from the high pressure pump ? Extreme pressure fuel at that site so goggles and a rag around the fitting are mandatory.

Is this correct @Stu Jackson ? Works on a Yanmar.

 

[Better_Angel]

Yes, this is the plan at this point.

I had a fuel problem in 2020 when because of COVID the marina was shut down, etc, etc and we did not splash until August.

I changed the 3 filters and bled the system at all the bleed points and the problem went away.

The only difference between then and now is that in 2020 I had the Engine Stop in the Run position, so I will be doing that again.

I already have new replacements for all the filters (Racor, lift-up, secondary). I also have a supply of new clean diesel that I can plumb directly into the Racor to eliminate the old supply in my fuel tank as a variable.

I won't be able to get to it until next weekend though and I want to gather as much information and any other supplies I might need before then.

 

[Stu Jackson]

Is this correct @Stu Jackson ? Works on a Yanmar.

Not necessarily. Our M25 NEVER needs to crack an injector, there is a handy dandy separate fuel bleed screw/knurled knob just before the injectors. Don't know if M18s have it, but they, too, are Universals. I suggest the OP look at his engine manual to find out. Bleeding injectors sounds wrong.

Then there's always this if he thinks it's fuel:
Fuel Starvation and The Obscure Check Ball Valve
Fuel Starvation and The Obscure Check Ball Valve
and
Fuel Starvation and The Obscure Ball Check Valve

 

[kloudie1]

The engine stop will stop the high pressure pump from pumping to the injectors.. Your injector pump is probably OK.

 

[Better_Angel]

Not necessarily. Our M25 NEVER needs to crack an injector, there is a handy dandy separate fuel bleed screw/knurled knob just before the injectors. Don't know if M18s have it, but they, too, are Universals. I suggest the OP look at his engine manual to find out. Bleeding injectors sounds wrong.

Thank you.
I've been looking at pics of other Universal engines and have seen the round knurled knob / bleed screw. I do not have that, it's just a plain hex-head screw.

 

[Better_Angel]

Then there's always this if he thinks it's fuel:
Fuel Starvation and The Obscure Check Ball Valve
Fuel Starvation and The Obscure Check Ball Valve

Thank you for this but not an issue here.

When I had fuel problem in 2020, I had just bought the boat and did not have much history on it. Accordingly, I disassembled the Racor completely, cleaned it and replaced all of the o-rings, etc. When I opened it again it looked just as clean as it had been 3 years ago.

 

[Davidasailor26]

The engine stop will stop the high pressure pump from pumping to the injectors.. Your injector pump is probably OK.

If the stop is pulled it stops fuel to the engine. That would explain the lack of fuel at the injectors.

 

[Stu Jackson]

Thank you.
I've been looking at pics of other Universal engines and have seen the round knurled knob / bleed screw. I do not have that, it's just a plain hex-head screw.

The knob and teat on it bleeds the fuel train BEFORE the I.P.
Early M25s had a bleed SCREW, that when opened would need fuel all over the engine if not done carefully. Later M25s (and XPs) switch to the knob and return the bled fuel to the return line.

 

[Better_Angel]

Later M25s (and XPs) switch to the knob and return the bled fuel to the return line.

Like this, yes?

I don't have an available port to hook up the return line, but I can keep it plugged up normally, and drain it into a cup or whatever if I have to bleed the system again.

 

[Better_Angel]

UPDATE:
Yesterday I closed everything up.
I supplied clean, new (automobile) diesel into the Racor via a soda bottle and some appropriate plumbing fittings.
I bled at the input to the high-pressure pump.
Cranked the engine, and VIOLA !!! it started and ran like a champ (knock wood).

My marina only goes until Oct 15, so I only need to run the engine a couple of times before hauling out.
I would like to keep going this way and not experiment with quality the gas in the gas tank.

1 - Does anybody have any guesses as to what might have gone wrong originally?

2 - Am I doing any damage running the engine this way?

3 - My tank is very difficult to remove.
I am assuming that the on-board fuel is the culprit, but I don't know how to best deal with this.
Any advice in this regard will be appreciated.

Thank you all for all your help,
Gabe