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| BMC idle at full throttle |
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Message |
    
david_h
New member
Username: david_h
Post Number: 1
Registered: 12-2015
| | Posted on Saturday, December 05, 2015 - 06:46 am: | 
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I have recently installed a BMC Commander (2.5) to replace the existing Commander that ended up full of water after an issue with the stern gland. Much to my amazement I managed to find on Trademe (NZ EBay equivalent) the same exact motor which had be stored for the first 30 years of its life and had less than a thousand hours on it.
The new Commander started immediately after I got everything connected right, much to my delight, but will only run with the throttle pushed to maximum, at idle speed. If the throttle is moved back just a little the engine stops. It has a mechanical governor. The guy I bought it from had it running when he removed it from his boat and I totally trust that he had no issues with it at that point. I haven't needed to do anything on the fuel side of things except install a new fuel pump which happened to come with the motor. I have the shop manual and Nigel Calder's diesel book but haven't found anything there. Totally mystified as to what the issue may be and am desperately hoping someone here might have some ideas as to what the problem might be! |
oslin04
Senior Member
Username: oslin04
Post Number: 87
Registered: 10-2006
| | Posted on Saturday, December 05, 2015 - 12:01 pm: |
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From what you say David h and Assuming there is no air in the system and your new fuel lift pump is working correctly with clean fuel filters from the tank ? you will need to get your injection pump re built as it has been standing for some time it is possibly gummed up and the governor might be sticking as well.
Keith Marine Engineer |
david_h
New member
Username: david_h
Post Number: 2
Registered: 12-2015
| | Posted on Saturday, December 05, 2015 - 08:05 pm: |
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Hi Keith, your reply is much appreciated! Yes, system is bled and filters replaced etc. I was beginning to think I might need to pull apart the injection pump/governor, the engine hasn't been going for over 3 years. I've never really done anything like this before except valve clearances on a couple of bikes and carby strip downs. I'm fine at following instructions, do you believe this might be something I could do myself using the shop manual or would you recommended I get a mechanic to do it? The boat is now on a swing mooring so is a somewhat logistical issue getting someone out there, I would probably have to remove and install the pump myself anyway... |
oslin04
Senior Member
Username: oslin04
Post Number: 88
Registered: 10-2006
| | Posted on Sunday, December 06, 2015 - 04:25 am: |
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Hi David,
No it is not something you can do yourself unless you have all the correct gear and testers, injection pumps are built in dirt free conditions and are a precision component, but you can remove the injection pump and take it to a company who rebuild injection pumps and injectors, there will be a company near you,
The pump is on a master spline and can only go in one way but take note of the timing marks on the side before removing it which will save you re timing the engine on refitting.
Keith |
oslin04
Senior Member
Username: oslin04
Post Number: 89
Registered: 10-2006
| | Posted on Sunday, December 06, 2015 - 04:52 am: |
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David, just a thought you have checked to make sure the lift pump you fitted is the correct part ? quite often they look the same but have different length arms which can effect delivery to the injection pump.
Keith |
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