Engine Starting Problem & Glo Plug Solenoid

[britinusa]

Long story - just trying to get all the facts on deck.

Went down to the boat to do an oil change, so needed to run the engine for a few minutes.

Here's my engine start routine:
. Check all Thru hulls are open
. Check Dipstick oil level.
. Engine in Neutral
. Throttle at minimum
. Engine Master switch on Electrical Panel in Closed position (6o-clock)
. Key switch On
. Hold Blower Switch down for 30 seconds
. Release Blower Switch
. Press in on Glow Plug button for 15 seconds.
. Release Glow Plug switch
. Press Start Switch - Normally Engine starts without fail.

But it did not start that day.

I had 50% tank of fuel according to my (newish) fuel guage, as I  had just put in 5 gallons from a portable tank.

I have never had to hold the start button in for 5 seconds, let alone be concerned about back flooding the engine.

So I left the engine to sit quiet for a few minutes and tried again, no luck.



All of the reading I have done on this site lead me to believe that it was either a fuel issue or an air in the line issue.

Next I opened the drain screw at the bottom of the Racor fuel filter (yes, it's Filter - Pump - Engine Filter routing)
No fuel came out! Tightened the drain screw.

Ah ha! Is it the fuel pump?

I opened the bottom cover of the fuel pump and no fuel came out! Replaced the lower cover.

Getting somewhere.

Next I disconnected the fuel output line from the Pump and replaced it with a spare hose long enough to reach into a can on the head floor.

Turned off the Engine master switch and turned on the Engine key switch.

Back in the cabin, I turned on the Engine master and could hear the fuel pump clicking and after a few seconds, fuel came out into the can. Turned off Engine Master switch.

Removed temporary hose and replaced engine hose to the fuel pump.

Now I needed to bleed the engine, and this is something I have feared as previously mentioned, but from all I have read here, the engine is self bleeding!

So all I needed to do was let the fuel pump tick over for a while.

I let it tick over for 10 minutes, and it settled down to a rapid click.

Back into the cockpit and pressed down on the start button and Varoom! Started like there was never a problem.

Ok, now to think this through...

I'm wondering if the problem is in the fuel take up tube in the fuel tank.

If the take up tube is not near the bottom of the tank, then it will suck air at some point even though the tank has fuel.

So, perhaps on my last trip out, we were actually close to running out of fuel when we got back to the slip.
When I tried to start the engine, perhaps there was no fuel in the line!

But it gets complicated just a bit!

Next day, engine started right away as normal. And I added another 5 gallons of diesel to the tank.

But the next day, after a really cold spell (remember this is South Florida - Everything is relative) with the temps dropping down into the 50s, the engine would not start!
So, I let the fuel pump run for a while and tried again, no luck! Dang! We're scheduled to be the first boat to peel off from the 3 boat raft up.

Then I figured, perhaps the engine is really cold and 15 seconds of glow plug heating is not enough.

I held the glow plug switch in for about 45 seconds. Then start - Varooom! beautiful.

Perhaps the second event was due to nothing more than the unusually cold conditions.

Next step is to empty the aft berth, remove the bulkhead adjacent to the fuel tank and pull out the fuel take up line.

Thoughts?

Paul

[KWKloeber]

Long story - just trying to get all the facts on deck.

Paul, refresh my memory -- an XP, correct?

Some thoughts - probably not complete though..........

Yep make sure that the fuel pickup has no screen in it (this is a Westerbeke Service Bulletin.)
Check to see that all your glow plugs are getting hot (try not to burn your finger tip.)  Check resistance on them to see if they are the same or one is whacky.
Be aware that energizing the preheat for that long can burn out a glow plug (they are 10 volt and don't care for 12 volts that much.)

With your bleed screw closed, the pump should back pressure once the lines are full and start clicking slowly, not fast.  Was the bleed close or partially open?

I have my bleed NOT connected to the fuel return line -- everyone asks why I don't connect it (it's so much easier, bla bla bla bla bla bla)  -- For precisely the reason it would have helped you instantly - I can open the bleed, catch it in a plastic cup and tell if I'm expelling, air, foam, clean fuel, a strong steady stream, etc.

I also have an off / on / momentary on switch to install in the engine compartment to activate the fuel pump and/or starter for bleeding and troubleshooting (avoids the cockpit ups and downs and dang alarms.)

ken

[britinusa]

Yep, M25XP

paul

[Ed Shankle]

Paul,
I assume the engine was cranking, just not starting?
Also, do you have a glow plug solenoid? If not, I don't think 15 seconds is enough time. If you do, it should be enough.
Maybe some air getting into the fuel line somewhere? With only a 15 sec glow plug time, might not be enough time to self prime.

Ed

[KWKloeber]

PS:  Really no need to activate the blower -- it's a diesel.  Though it won't hurt anything.

kk

[Ron Hill]

Ed : It could be your fuel pickup tube. 
The tube itself only goes down in to the tank about 90% of the way and the end is about 2 inches above the bottom of the tank.  There should be a piece of 3/8" fuel line (about 4" long) attached to the pickup tube. 
The idea is that the fuel hose bends and lays horizontal on the bottom of the tank picking up fuel from the tank bottom.  There should not be a piece of fine metal screen stuck in the end of that hose (that's what gets clogged!!)  Remove that screen if it is there.

Sometimes that hose comes off if the fuel pickup tube is not carefully removed.  You might want to check that!

BTW, 30 seconds ON for the glow plugs is what is recommended in your engine manual for an M25 and M25XP engine start.
If you look in WiKi and do the "glow plug solenoid modification", you only need 10 seconds of ON to heat them up for an engine start.  Not that hard to do !!   

A few thoughts

[mark_53]

Did you check your engine cut off handle! Is it in the down position? Scratched my head once or twice why the engine wouldn't start. 

[sailaway]

I have a m-25 engine an the glow plug time is a 50 count or she want start in cool weather wish I where in Florida , its 10  here today lake Erie.  Charlie

[Stu Jackson]

"50 count"

Is that like linen sheets? 

Let's be careful out there.

The reality is that the goal is to not burn out the glow plugs by having them engaged for too long as compared to the time needed to start the engine when cold.  Cold varies by regions, since my 40F in winter can be "warm" compared to Chicago's 35F in springtime.

The amount of TIME required is based on whether or not one has installed the glow plug solenoid (whether new boats or old), so one needs to mention that.

And TIME needs to be based on actual seconds, not counts.  I use the old method of (gasp!  ) a wristwatch or 1,000 - 1, 1,000 -2, etc.  With my solenoid I never have to go beyond 12.

With no solenoid 30 seconds is recommended as a starting point.

Suggest one does the individual test I mentioned earlier to minimize the time, and also mentions whether or not a glow plug solenoid is installed and what methods one uses to "count."

As mentioned in the hundreds of glow plug topics on this forum & website, when the engine is warm, one usually does not need the glow plugs, just push start.

[Lance Jones]

I had a similar problem a couple of years ago. Before explaining, here are some comments off the bat:

1) No need to run the blower
2) Without a doubt, if you do not have the solenoid modification for your glow plugs, drop everything you're doing and do that.
3) Also make sure you have the upgraded wiring harness in place too.

It sounds like you're doing the right things to solve the problem. One step I would recommend is that once you are sure you have the fuel system totally bled, close the bleed valve and then back off 1/4 turn or so. That will make your line self bleeding. I believe that is a Ron Hill posting from a bit ago.

[KWKloeber]

If you add a slave relay for the glow plugs, read this and the caution:

http://c34.org/wiki/index.php?title=Faster,_More_Efficient_Glow_Plug_Heating_with_a_Solenoid#USING_A_RELAY_TO_FIRE_THE_GLOW_PLUGS:

kk

[britinusa]

I'm glad that I waited a few days before addressing this.

I'll be on the boat in two days time. So I'll check the fuel pickup tube and see if the glow plug mod is in place.

paul

[SPembleton]

For what is worth, i have an 86, do not have a solenoid installed yet, and i do a 20 count on the glow plugs.  (Solenoid to be added this spring.)

[mark_53]

For what is worth, i have an 86, do not have a solenoid installed yet, and i do a 20 count on the glow plugs.  (Solenoid to be added this spring.)

My M25XP starts in 15-20 seconds without the solenoid but I'm in a milder climate than you mid westerners. When warm, no need for glow plugs at all. For me, it's not worth the effort and risk of burning out glow plugs to install a solenoid for a 5-10 second cold start advantage. That is the least time consuming part of preparing for an outing.

[britinusa]

I took the fuel take up tube out. The end filter has been removed, and the tube reaches down pretty much to the bottom of the tank. The tube is a 2 part product. Top part is a metal tube, lower part is a rubber type hose that is pushed up on the metal tube for several inches and held in place with a metal spring clip. But the lower tube is so tight, I doubt it would ever budge unaided.

Also, there does not appear to be any splits in either tube through which air could get sucked in.

So I don't think it's a fuel takeup issue.

I dipped the tank and guestimate it to be really close to the fuel level indicated on the gauge (at 3/4 full)

So I don't think it's a gauge issue as the gauge matches the current fill and it appeared to follow the fill as I added fuel earlier.

My current suspect is simply that it's been so cool here recently (sorry for you folks that 50F is considered cool  ) so my prime suspect is not normally running the glow plugs long enough prior to hitting the start button.

Today we counted 20 seconds of glow plug and the engine started 1st time.

I'll start a new thread on another engine issue.

Paul