QSM 11 Mysterious shutdowns

[Rich Dancaster]

I have a pair of QSM 11s in a 2008, 50′ Altima trawler. I have owned the boat for 3 months and recently the starboard engine will shut down for no obvious reason. I am in south Florida with mild temps. The engine runs perfectly and suddenly turns off ( usually after operating for 30 minutes to an hour) as if I had pressed the shutdown switch and turned off the ignition.
When this occurs the ignition to the starboard engine is dead i.e. no power to the instruments (froze in last position) on the starboard side and the single installed Smartcraft unit goes blank and the engine will not crank (no power to the starter with ignition switch on and starter button pressed.
To date the shutdowns have occurs at lower RPMs from idle up to 1,000rpm. I have done some basic troubleshooting: Batteries load tested and cables cleaned and secure, alternator output 28v , engine ground checks, 5 fuses on the engine wiring harness checked ok and no corrosion. Fireboy switched off at the circuit panel, Smartcraft multi pin connectors pulled to disable the Smartcraft, ignition key on/off switch bypassed the engine still shuts down . When the engine shuts down battery voltage is 26v (isolator installed in the system) and voltage at the ignition switch is only reading 7 volts???
Now the oddest thing is after a variable amount of hours from 3 to 8 shore power re-connected or not, the problem disappears and the engine will start and run fine (all power from idle to WOT) for another 30 minutes to an hour???
Any help solving this issue would be greatly appreciated!!

Rich

Topic

[dbbwell]

QSM 11 Shutdowns

This thread was a lifesaver for me as my Maritimo with QSM11’s exhibited similar problems.  The engine would shutdown, the Smartcraft screen would go blank, and the engine would only restart after a rest period of thirty minutes or so. 

The final shutdown occurred shortly after I cranked the boat, but I was still tied to the dock so I could do some trouble shooting.   

Thanks to this thread, I had a Power Probe set up in the engine room.  After the third shutdown I checked the output of the TR300 DC to DC converter (24 volt to 13.7 volt) and the output was only 3.4 volts.  

As a confirmation, I swapped the TR300 outputs from one ECM to the other.

Ordered a new converter from SBMAR and I’m back in business.  

 

 

 

 

[Tony Athens]

Clogged pick-up? Only way to troubleshoot that is to install a  vacuum gauge–Then, their is no thinking. Teach your mechanic something

[bmarascia]

Have same problem qsm11

changed out racors, secondary filters , had a code 422 coolant sensor. Replaced coolant sensor and reset Ecm. No good . Had fuel tank polished for  clea8 hours no good lots of sludge and black flakes.  Just spoke to Cummings mechanic. Says the starboard side fuel pick up is lower in tank . Thinks the fuel pick up clogged. 

[bmarascia]

Hello did you find the problem with starboard side only getting max rpm of 1400???? I have the same issue. Changed racor and secondary filter. Had fuel tank polished. Had a fault code 422 was coolant temp sensor and replaced and cleared codes still no good. 

[Tony Athens]

QSM 11–Issues

What type of instruments do you have?  Look at the alarm code history? Look at throttle voltage  / % . Look at boost, GPH, IMT, etc etc..  One engine could be re-rating to protect itself….What is the history on servicing the aftercoolers?

Your engines computer has all of this information to give you. But you need the proper digital instrumentation to read it.

 

 

 

 

[bmarascia]

2002 qsm11 635 hp , port runs up to wot starboard  on up to 1400. Both motors were running perfectly and out of no ware starboard did this. Drain slight crap out of racor and installed new filter. Drained secondary filter some slight junk and replaced filter. Ran engines same thin. Checked all grounds and supply lines good. 12v to all when not running. Removed fuel solenoid and cleaned and re installed. Still only 1400 on starboard side. 

[Philip]

Glad you were persistsnd and found the issue!

I assume a little cleaning and WD solved the issue….

[Rich Dancaster]

RE: Mystery solved, Thanks all!

Thanks to Tony’s Tips, Understanding your SmartCraft 1.0 “Medusa” Vessel Adapter Harness”. I continued to check for the source of the low voltage at the Medusa harness. This led me to a black box (lable not legible) but turned out to be a voltage regulator (24v to 12v). A quick check determined that it had 24v going in and only 5v coming out. Problem solved! Having access to the resources on this forum and the diagram of the medusa cable was priceless!

Cheers!
Rich

[Tony Athens]

99+++% , of all “mystery shutdowns” on an engine are related to a poor electrical connection(s)…….. That is a given.

You ain’t going to find it on a web site——————————you are going to find it with a basic understanding of what a clean, tight, and lubed electrical connection needs to be in a marine environment . You also need a set of eyes that see the signs of salt water environment and what it does with electrical connections….

So, what it all come down to is crawling around down in your engine room and doing your “due diligence” as to checking every connection–On your QSM 11. I’d start with the batteries, the main switches, the starter, the fuses, all main grounds, and the fuel solenoid on the back of the Celect Injection pump.

Post some good pictures of your engines showing all.. Let’s see what things look like down there…

Tony

[Philip]

If you found two fuses with low voltage you need to go past that point towards the battery and keep checking.

Did you remove the fuse and confirm the socket was clean and tight? Did you check the back side of the fuse holder for connection cleanliness and tightness?.

Someplace between the fuse and power supply (Battery) you will find something…. I doubt it’s the ECM.

[Rich Dancaster]

RE: QSM 11 Mysterious shutdowns

Thank you for your reply Phil! Yes when taking the voltage reading I had a direct ground. I followed your advise this evening and after the shutdown which only took :15 minutes today I checked the voltage at the ignition switch and found 2.3 volts. from there I went to the 5 fuses on the wiring harness in the engine. The 3 fuses closest to the ECM were good reading 26v the 2 fuses farther out on the wiring bundle from the ECM (normally 13v) were reading the same as the ignition switch 2.3v. I have Glendinning electric controls and the input to the control box in the engine room on the lead labeled “Shift and Ignition interlock” had the same 2.3v reading on the only pin connection with voltage. I found the cannon plug that connects the engine wiring bundle to the rest of the boat and disconnected it. The fuses at the engine still had the same readings and as expected the ignition and Glendinning control box lead noted had zero.
Looks like the problem should be in the wiring bundle or the ECM or other black box on the engine. Interesting that 1 hour after the shutdown the voltage reading at the two low voltage fuses had increased to 4v and 30 minutes later to 5v. Hmmmm???
Does anyone know if the ECM or other box on the engine could cause this issue?

Thanks!

[Philip]

Sometimes these gremlins can be a hair pulling exercise in elimination.

How are you measuring the 7v? I assume your connecting the negative of the meter direct to the battery or negative bus thus eliminating a bad ground. With this assumption:

I would follow the power back from the 7v at the ignition switch all the way back inch by inch to the battery checking as you go. When the switch is reading 7v and you find 24v you will know the issue is between the two points. You might have to prick the wiring harness as you go inch by inch if needed….

I suspect you will find a dirty connection somewhere that is heating up after 30-60 minutes of running adding resistance until it drops below minimum voltage to support engine operation.

Since every boat is different there is no one answer of where to look.

Keep us posted and we will keep throwing ideas until it’s solved.

Phil

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