ZF Electronic Controls - Fails to Shut down an Engine

Hi all,

Thanks for being the sounding board and provider of wisdom.

Our new to us 2005 Mainship 430 aft cabin trawler with twin 370 HP Yammers and ZF MODEL: 80-1A - 2.5 transmissions with electronic controls has been a very smooth experience until last weekend.

It seems the starboard engine won’t shut down occasionally when we use the stop switch at either the fly bridge station or the station in the salon. It occurred two weekends ago once, but last weekend it would not shut down at the fuel dock for over 30 minutes.

We tapped on the control box in the engine room – because there is nothing else exposed. We played with the solon station switches and noticed that when we pressed the switch, there was a faint click at the auto fire suppression system status gauge. After trying to determine what the problem was for close to 30 minutes, we pressed the off switch and it worked. We had no other issues during a day of cruising where we stopped the engine several times.

Has anyone run into this situation before with the same equipment or even different equipment?

If the electronic shut down fails, how else do we safely shut down an engine?

JimL

Don't know your exact setup. I have a Yanmar 30GM with electronic controls. These controls open and close the stop solenoid. Check your manual and determine where the stop solenoid (or fuel solenoid) is located.
Determine how you can safely manually operate it to shut off the engine. The solenoid is typically attached to a lever which can be pushed or pulled and this will shut off the fuel to the engine.

Most likely the solenoid is failing and needs to be replaced. You can test this by putting a meter on the wires to the solenoid and having someone press the stop button. If you have power when the button is pressed then the solenoid is failing. Alternatively and simpler you can just buy a replacement solenoid and swap out the old one. Suggest you buy a replacement as they are not a bad spare to have. I need to replace one on Bay Pelican every few years.

As noted the problem is most likely the stop solenoid. Check to see if there is power to the terminals when you hit stop. If no power then likely a bad connection.

Is there is power then check for solenoid movement. If no movement then solenoid is bad.

If movement is ok then linkage needs adjustment.

David

My friend who has 500hp Yanmars had a similar problem with the red stop button not working. In his case the stop button's insides were corroded and had to be replaced.

A "no stop" is unrelated to the electronic controls. Just a button on helm and a solenoid on inj pump on rh front of engine. Lever is external, if it does not stop, just go to engine and pull the lever by hand. It's right there in plain view.

Ski in NC said:

A "no stop" is unrelated to the electronic controls. Just a button on helm and a solenoid on inj pump on rh front of engine. Lever is external, if it does not stop, just go to engine and pull the lever by hand. It's right there in plain view.

Click to expand...

Agree w/ Ski & others re this NOT related to ZF controls

However - if you have an auto fire suppression system and are not getting V to the solenoid you should also check connections to the fire suppression control box - mine is located under the helm panel

I had alternator issues (not charging) and traced it down to improper wiring to the control box.
In your case if it works properly but intermittently it might be lose connections at the control box

Here's a link w/ typical wiring diagram of this type of system Fireboy Engine Shutdown System

Thanks everyone. I'll check the connections and will also locate the stop solenoid on the engine.

Don, regarding a loose connection in the 'control box', which control box and where would I find it? under the helm panel?

JimL

jimL said:

Thanks everyone. I'll check the connections and will also locate the stop solenoid on the engine.

Don, regarding a loose connection in the 'control box', which control box and where would I find it? under the helm panel?

JimL

Click to expand...

Do you have an ER fire system?
If so control box likely under / near helm
If Fireboy should look something like the link shows & includes schematics
If not ignore my comments

Thanks Don, it's a Sea Fire unit. I'll poke around for the control box.

JimL

jimL said:

Thanks Don, it's a Sea Fire unit. I'll poke around for the control box.

JimL

Click to expand...

Jim
Have you found the stop solenoid and confirmed no power getting to it.
I agree w others... that's the place to start to determine if it's a solenoid or power problem. If no power then work from SW to engine.
A long wire, alligator clip and meter help check continuity between distant points and narrow down which segment is the problem.

Don,

I stopped by the boat yesterday and located the solenoid on the engine and the relay that controls it. I need to spend some time on it this weekend and try to get the situation to replicate itself. It's an intermittent problem, so I need to check before I start the engine and after I start the engine. I'll also need to gain access to the helm panel which is accessed from the FWD Head shower.

The intermittent no stop issue is with the STBD engine and the solenoid is on the outboard side of the engine. Not looking forward to working over an engine while it's in operation. I better do this before it's warmed up.

Jim

jimL said:

Don,
Not looking forward to working over an engine while it's in operation. I better do this before it's warmed up.
Jim

Click to expand...

Jim
Stop solenoid should work w cold engine.
Yanmar ops manual recommends for start after extended layup to hold the stop buttom while cranking to pump oil before cylinders fire.

Re fire suppression system being involved in this problem, the systems I've seen are all designed so that a failure, loss of power, blown fuse, etc. will shut down the engine, not prevent a shut down. The fire system needs to be functional to enable the engine, otherwise it's disabled. Now I'm sure there are some corner cases where this might not be true, but I think you are much more likely looking at a stop solenoid or wiring issue.

twistedtree said:

Now I'm sure there are some corner cases where this might not be true, but I think you are much more likely looking at a stop solenoid or wiring issue.

Click to expand...

Twist...
I agree...my reason for even mentioning the fire system is that it is in the circuit connected to the solenoid and MAY be worth checking connections if it is found that power is not getting to the solenoid and other obvious connections are good.

I have the exact same boat and engines and have had that exact problem. It turned out to be the stop solenoid mentioned earlier in this thread. If you swap solenoids between the two engines and the problem moves to the other engine it will confirm/refute this. We now carry two spare solenoids; I think they are about $25 each. BTW you can always shut down by pushing the fuel stop lever by hand. Be careful not to burn yourself on the stbd engine.

Thanks everyone. I did find a supplier for the solenoid, and will be ordering a few as spares. This weekend I'll be prepared to trouble shoot the system based on these comments.

JimL