Testing/bypassing W46 Shut Off Solenoid

[bcboomer]

Fired up the old girl last week (1993 Westerbeke w46 in a 1986 O'Day 40). No problems, clean exhaust, purred like a kitten for 5 or 6 minutes. Then stopped dead, cranks but won't fire.
Replaced the primary fuel filter, just in case, but it looked OK. No start.
Pulled the return line at the tank and the lift pump circulates fuel through the system.
Okay we've got air and probably fuel but no start.
The next thing that comes to mind is the shut down solenoid. Checked connections at ignition switch and added a bus bar to the switched power because there were a bunch of wires on 1 #8 screw terminal.
Some DPO has run a switched wire to the lift pump, bypassing the double light blue factory wires. Checked the wiring diagram in the W46 manual, not the same Okay leave that alone for now. Traced the wire from the shut-off solenoid to a connector with 2 light blue wires going into the harness.(Numbered 17 and 18) One of these is broken clean through. Maybe its been cut in the past, maybe it broke in my tugging but thinking back it was a clean break with no corrosion. This is the only part of the engine that I can't access easily and can barely get a hand on.
Fixed the broken wire, still no joy. Hot wired the solenoid, still nothing.
Checked for continuity through the solenoid. I forget what the resistance was but its not open or shorted.
Soooo, does any one know how to test the blasted thing without pulling it out?
Better yet, does anyone know an alternate source of the correct solenoid? It's a CAV pump and probably fits other engines. I've looked at the Mitsubishi 4DQ5 manual and its a different pump.

[Patience 242]

Can you just disconnect the solenoid mechanically to take it out of the picture?

[bcboomer]

It threads into the bottom of the injection pump. I suspect if I remove it I'll have major leak. I should be able to remove it and then take out the little spring and the pin that seals off the fuel, but it's in such a difficult spot I'd like to be able to be sure it is the problem.
I wish I had a wiring diagram that was correct for this installation. I suspect there could still be a wiring problem but I don't know enough to test the circuits without a diagram. I just know enough to get into trouble

[unclemack]

"probably fuel" is a bit of a worry. You didn't mention bleeding the system after checking the filter, I'd generally do that even with a Racor.

Should be able to hear electric fuel pumps and stop solenoids click when momentarily powered.
Pulling an injector will show whether solenoid's working or not.

[unclemack]

Given the broken wire you found the solenoid's the most likely issue but if not...

Very rarely the nuts holding the injection pump to the face plate (slotted holes) come loose allowing the pump to swivel and the timing to slip. Only seen it a few times in nearly 50 years, guessed nuts must not have been properly torqued on assembly.

If you've ever started a diesel on EasyStart/ether this should make sense -

EasyStart's something I try to avoid using but you can spray diesel into the manifold with a little handheld squeeze trigger sprayer bottle. Set spray bottle to finest possible mist.
I use it more with petrol to confirm an outboard's carburettor is the problem. Very quick test.

Air cleaner needs removing obviously and don't go mad spraying. If it doesn't even cough or chug in the first couple of seconds forget it & go back to basics.
If it fires you can actually keep it running after a few seconds' practice. Can sometimes even clear air locks this way.

Work safely though - glasses, gloves, extinguisher, arm's length and another person nearby - watch out for unexpected glow plug ignition in the manifold.

Hope it's some help to you

[bcboomer]

The system self bleeds in 1 to 2 minutes from an empty filter. That's one of the things I like about this engine.
No air filter to take off, just a coarse screen so starting fluid would be pretty easy, BUT, I've seen head bolts stretched that way.
I'm trying to avoid loosening an injector and spraying diesel around. My boat has zero diesel odour but I guess I have no choice.

[seasick]

Here is the W46 manual in PDF https://www.westerbeke.com/operator'...6_oper_man.pdf wiring diagram on page 22:

[seasick]

This manual in my previous post shows a shut down lever on the injector pump (pg15) this seems in contrast to your description. There also appears to be a looped circuit through the oil pressure and coolant temp that could shut the puppy down if either measured conditions out of norm.

[bcboomer]

Thanks for the manual. The one I have is #34907 dated May 1987.
It is the same wiring diagram. It seems this was a time of transition from a cable operated manual shut down to a fuel solenoid.
The wiring harness was apparently changed but the only diagram change is the little #14 circle just above the "fuel lift pump". My boat has double light blue wires to both of these.
Also interesting is that the list of engines beside the lift pump doesn't include the W46. Maybe Westerbeke just kept using the wrong diagram.
My warning buzzer has never worked so maybe it's just another example of some sloppy wiring "fixes" by someone who really didn't know what they were doing. Maybe the broken wire was cut intentionally.
Good point about the pressure and temp switches. The pressure switch is closed when not cranking but I haven't tried it while trying to start.
I'll dig further into that.

[zboss]

We have the same engine - Westerbeke 46 with Mitsu block. You may want to look at the injector pump.

How many hours on the engine?

[bcboomer]

Hard to know how many hours (hour meter is dead). Previous owner lied through his teeth about enough things that I don't believe anything about the boat before I bought it. Second owner back put in a new engine in 1993 (I have the bills). He told me that it had less than 300 hours when he sold it and DPO said he only put on 200. At any rate virtually zero oil consumption over the 50 hours I have put on and a very clean exhaust.
It only smokes at full throttle because the DPO replaced the 18X8 prop with a 17X12. Claims it was for better fuel economy and it does seem pretty good.
Typically a pump should have acted up rather than just quitting. I had lots of experience with CAV pumps as a Peugeot dealer and we found them much better than the Bosch.

[tdoster]

I believe the W46 is opposite of what most people consider normal. When you turn the key, the solenoid activates to allow the fuel flow through the injection pump. Unlike other engines where you press a switch to activate the fuel solenoid to shut off the fuel flow (like pulling the lever), the W46 you just turn off the key and it stops. Turn the electricity off to the solenoid and it shuts down.

You should be able to visualize this by attempting to start the engine and seeing it activate. Make sure the solenoid fully extends and you can push it manually, if need be to determine if that is where the problem is.

Also, if a W46 is sitting around for a long time, pull the lift pump filter. More than once on the Westerbeke self priming engines I have found rust in there. Probably why Westerbeke changed the part to a standard non-internal filter pump on the superseded part.

Remember, the average W46 has three filter systems, and two on the engine itself. The one in the lift pump, the spin on, and anything you have for water separation combo between the engine and the tank.

[unclemack]

Originally Posted by tdoster

Also, if a W46 is sitting around for a long time, pull the lift pump filter. More than once on the Westerbeke self priming engines I have found rust in there. Probably why Westerbeke changed the part to a standard non-internal filter pump on the superseded part.

dammit I knew there was something...

Soon as I read "wire to the lift pump" I thought "filter" and then forgot.

Still, at least there's some comfort in being ancient & gerry enough that people don't expect much anymore

[bcboomer]

I'll take a look at that little filter but the fuel I have coming out the return line had already gone through it and there was more than enough volume to run the motor.
I can't see any movement at the solenoid because it is an internal plunger completely contained in the solenoid. An internal spring pushes the needle into the seat to stop the fuel flow and power to the solenoid should retract it and allow fuel to flow. The motor started and ran fine for a few minutes then stopped dead. I think fuel starvation should have shown as rough running.
I'll dig back into the wiring and if I can't solve it that way I'll pull the solenoid and remove the needle.

[unclemack]

Originally Posted by bcboomer

The system self bleeds in 1 to 2 minutes from an empty filter. That's one of the things I like about this engine.
No air filter to take off, just a coarse screen so starting fluid would be pretty easy, BUT, I've seen head bolts stretched that way.
I'm trying to avoid loosening an injector and spraying diesel around. My boat has zero diesel odour but I guess I have no choice.

Yeah, agree on starting fluid which is why I suggested diesel in a spray bottle.

I wouldn't let an injector spray diesel anywhere but into a bottle or jar.
Sometimes all four injectors into four bottles