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Volvo MD6A difficult to start

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"My MD6A has difficult time to

"My MD6A has difficult time to start when is cold (even if is air temp in the 70-80s). I have to use my starter for long time and once it's started, although take time to reach normal RPM, everything is fine, still able to push my 3.5 tons boat at 5-6 knots.
When it's hot everything is fine, and if I turning it off, it reasonably re-start again.
I cleaned the tank, replaced all filters. Tank was very bad, but now is perfect.
Diesel flow is good to injectors.
The engine starting process improved, but not drastically. Still using too mutch my starter.
I cannot continue like this, I'm afraid my starter will soon die..
I noted that during the starting process white smoke came out from exaust pipe. Once started everything is normal.

Any suggestion?
Thanks
Antonio"
 
"Hi Antonio, I have a very sim

"Hi Antonio, I have a very similar problem with my MD6A, including the white smoke. Did you solve your problem? Can you share the answer? Thanks!"
 
"Marc,
I have no answer nor s

"Marc,
I have no answer nor solution fund yet. I'm starting my engine with starter, not the best solution, but still able to sail...
If you hear something pls. let me know.
Rgds
Antonio"
 
"Just a stab at this, I'm

"Just a stab at this, I'm a new owner of an MD6A, so apologies if this is off base! Have you tried replacing or at least testing the thermostat? If that is stuck open or opening prematurely it will carry away the heat the cold engine needs to build up to run. That would explain why it runs normal when hot, as the thermo would be open when the engine is hot"
 
"Check 12v supply to the glow

"Check 12v supply to the glow plug(s), if they are getting power most likely majority the glow plugs are bad."
 
I had the same problem also. I raised the decompression lever to let the starter freely turn the crank which would then prime the system without wearing out the starter.
I found a small drip of diesel coming off the fuel injector pump at the stop fuel lever only when the engine was running. Turns out this leak was letting the prime back-feed from the injectors which in effect caused long term starting. Removing the plate that holds the throttle and stop fuel levers I found the O-rings were rather brittle with little cracks all around when stretched a little. You can get an exploded view online of the MD6A fuel injector pump very advisable to start with. I had the parts tolerances measured for millimeter dimensions and ordered the correct O-rings which solved the drip problem.

My engine now starts at the first flick of the switch hot or cold.

If any of you out there have the drip...get in contact with me, if you want to work on this yourself. I have (98) o-rings for those that need them. Plus the hard knocks I can save you in getting it all back in adjustment...

PS: lifting the decompression lever all the way in up position can jam the valves. I lift mine about half way just to where there is no commpression. Hand crank works fine if you have any voltage at all with the key turned on. Kind of fun in a way!

Yours in the sailing world, Me and my GSdog
 
Seems I may have the same problem.

Do you still have the O rings?

I would be glad to pay for them and the shipping.

Joe Langenfeld, 202-903-0309
6369 Lakewood Drive, Falls Church, VA 22041

Thanks,
 
I think white smoke can indicate water has worked it's way back in to the cylinder. If the motor is below water line, check that the anti syphon valve is not blocked up. Poor exhaust design can also be responsible.
 
There are no glow plugs on this engine.... I attached a hose to the end of the air cleaner intake and at the end of the hose I attached a 12 inch piece of pipe. I heat the pipe with a propane torch and then place the tip of the lit torch at the end of the pipe.
As the engine is cranking warm air is sucked into the combustion chamber which helps with the cold starts
On my boat this area is very accessable. I hope you have the same access
Jim's MD7a
 
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