Strange Problem with Engine/OD Shutdown

[jason78]

I had a strange problem yesterday. I wanted to see if I could get some ideas here. I started the engines cold, let them warm up to 100 or so then idled out through the no wake zone with no problems. When I got out of the no-wake, I took the engines up to about 1900RPM. Within a few seconds, the Smartcraft Alarm beeped and the Port trim indicator went to 1.4 then back to 0. Then it beeped again and the indicator went to 1.4 and back to 0 then the port engine died. Nothing happened on the Starboard side during all this. I seemed to feel a little pull both times the drive indicator moved but can’t be certain of that because the water was a bit rough.

I continued on one engine for a few minutes then put Starboard in Neutral and raised both drives to trailer to see if I could see anything on the drive. Visibility was bad so I put them both back down and then carried along.

I tried to start the Port engine and it fired right back up. I waited a few minutes and engaged the Port drive again and no more issues coming in. Got up on plane, steering fine, etc.

Any ideas on what may have happened? I was in plenty of water to I would not have hit ground. I never did see what the Alarm message was, it just beeped once and I saw the trim move up and down. I know I could have been caught up in a branch or something but not sure why the engine would have shut down.

Thanks
Jason

 

[floriduramax1]

I would check all battery connections and grounds. Sounds like an electrical problem.

 

[rkeats]

I had a similar issue, turns out it was low outdrive oil in the reservoir. When you get up on plane the alarm will usually stop until it gets very low. Make sure your levels are OK.

 

[floriduramax1]

I had a similar issue, turns out it was low outdrive oil in the reservoir. When you get up on plane the alarm will usually stop until it gets very low. Make sure your levels are OK.

Ha! I forgot about that! I actually had that happen to my port engine on my first trip out:smt021

 

[Alex F]

... I never did see what the Alarm message was, it just beeped once and I saw the trim move up and down. I know I could have been caught up in a branch or something but not sure why the engine would have shut down...

My first though was that you must have caught something, a branches or a loose line or something relatively soft since you didn't fill any kind of impact. However, I never heard where the drive would go up/down on it's own like the system engaged the switch on its own.

I had a similar issue, turns out it was low outdrive oil in the reservoir. When you get up on plane the alarm will usually stop until it gets very low. Make sure your levels are OK.

How's this related to the engine shutdown?

I had the low oil beeps once on my 240DA but the engine worked fine.

 

[David Paul]

Problems like this can be difficult to diagnose. If you had an alarm, the ECM likely set a code. I would have a Mercury technician hook up his scanner and read the code first. This may help resolve the cause of the problem.

 

[jason78]

Thanks for the tips. All the battery connections are tight and batteries are nearly new and showing no sign of other issues so I don't think it is ralated to that. Also, Gear Lube is fine and right at the "full" line.

A friend had suggested the trim indicator may be loose and made the ECM think the drive had gone up to trailer height for a second when I started seeing those readings and killed the engine because I was over the recommended RPM to be in while at trailer position. Anyone know if the ECM has such a feature?

I will probably have it scanned to check for a code.

 

[jason78]

I just spoke with my mechanic and he could not find any error codes in the ECM so I guess I may never know. He did say it is possible something is going on with that trim sender so he is going to have a look at that when the boat comes out for Spring service.

He also said that the ECM won't shut down the engine but will only put it in Guardian mode.

Jason

 

[Southpaw II]

I had a sensor go bad one time, and it put the engine in guardian mode....if I tried to accelerate, it would shut down completely. When I restarted, it would only do about 1500 rpm. Turned out, it was a faulty exhaust temp sensor.

Don

 

[DaleM]

A buddy of mine had a trim sender go bad to the point that the wire would short to ground intermittently. He'd get an alarm and then the motor would die. Why? The sender shorting to ground would kill 5V to the ECM which in turn would cause the motor to die.

 

[jason78]

A buddy of mine had a trim sender go bad to the point that the wire would short to ground intermittently. He'd get an alarm and then the motor would die. Why? The sender shorting to ground would kill 5V to the ECM which in turn would cause the motor to die.

Thanks Dale, that makes perfect sense to me. I will definitely have that sender looked at and probably replaced in the next couple of weeks when I have it out.

 

[DaleM]

No problem. I hope it's something that simple.

 

[DaleM]

Post back with what they find please?

 

[jason78]

Post back with what they find please?

I will but it may be another month. I did not plan to have it pulled till early-mid April. Unless of course it happens again- then I will move that time table up considerably.

Thanks
Jason

 

[jason78]

I wanted to give an update of sorts with some more informaton and see if it generates any new or additional ideas. This problem has occured several more times. I have been able to figure out when it "likes" to happen. It happens when I am crusing at say 1000-13000RPM. Out of nowhere, I get a single beep from SC and the Port engine slows down to about 600-700RPM. I can throttle back up to 1200 and stay there sometimes with no other problems and some times it will do it again. The first time this happened, the Port engine died. That has not happened again but the situation has occured several times since so I think the RPM must have just swung too low the first time it happened and killed the engine.

Once I figured out how to let it happen again, I was able to watch the trim indicator and saw no numerical movement out of it at all. When this happens, I get a beep then a pull to the port. Initially I thought this was a drive issue but I believe the pull is simply the instant drop on the Port engine in RPM. Maybe the first time it happened it just dipped too low and killed it. For a minute, I thought this might be a throttle cable issue but every single time this happens I get a single beep. I am not DTS so it has got to be something else. Is there anything else that the ECM can use to control RPM other than the IAC? I am almost thinking a sensor is going bad or the IAC is on the fritz and trying to fool with the IDLE at Lower RPMs. That IAC probably does not have 50 hours on it and this is not anything I have heard of an IAC doing. The boat runs great most of the time at low RPM and no problems at planing speeds. When I get the beep, nothing even flashes on the display. I watched this happen several times today and was locked in on the gauge set.

Any more ideas? I am starting to lean towward a sensor on the fritz rather than something with the O/D at all. After it happened the first time, I had the ECM scanned and the only recent event was an overspeed event logged but this happens at such a low RPM I don't see how that could be related. I have not had it scanned since.

Thanks!!

 

[Alex F]

IMO, IAC should be ruled out as it only affects the idle.

If you don't have the SC code reader I would get the boat to mechanic that can tell you what codes SC throws there. It may take a good mechanic 30min and the problem is solved. Unfortunatelly, this is what you have to do when dealing with the SC. I tell you that this is something I won't miss.

 

[DaleM]

Have you had a mechanic go out with you with the diagnostic computer attached? Some alarms are "soft" alarms. This means that as soon as you turn off power, the actual reason for the alarm gets cleared. "Hard" alarms are set and remain after power is turned off and can only be cleared by the diag system itself.

I mention this only because I had an alarm that was tripping randomly and while sitting at the dock with the computer connected there was nothing showing up in the logs. The problem was only discovered after running out on plane with the computer connected. The problem ended up being a shift indicator switch that was giving a false indication of going to neutral while actually being in gear. The computer caught this but as soon as the engines were shut down, the alarm cleared. $29 switch and $200 in labor later, no alarm

 

[jason78]

Have you had a mechanic go out with you with the diagnostic computer attached? Some alarms are "soft" alarms. This means that as soon as you turn off power, the actual reason for the alarm gets cleared. "Hard" alarms are set and remain after power is turned off and can only be cleared by the diag system itself.

I mention this only because I had an alarm that was tripping randomly and while sitting at the dock with the computer connected there was nothing showing up in the logs. The problem was only discovered after running out on plane with the computer connected. The problem ended up being a shift indicator switch that was giving a false indication of going to neutral while actually being in gear. The computer caught this but as soon as the engines were shut down, the alarm cleared. $29 switch and $200 in labor later, no alarm

Thanks for the tip Dale. I think that might be the next step. Based on the prior scan, I am pretty sure these are "soft" alarms. I am really starting to consider buying that Rinda Technologies scan software for this very reason.

Jason

 

[David Paul]

Another thing to look at the next time you go out is the raw water pump PSI on both engines. From what I know, Smartcraft is constantly monitoring the water pressure on the engine and will throttle the engine back if it does not maintain specific pressure readings at various RPMs. If you see the same water pressure on both engines then that is likely not causing your problem. But if the one engine has a much lower psi than the other, it is possible you have a bad pressure sensor or the pump or impeller may be bad.