Volvo engine experts help.

[mldpt]

Hi here we go again, my 2003 V/P has now been rebuilt, 4000 hours on the clock, Original problem, poor starting and excessive smoke, Had injectors serviced £180 cured the smoking but still poor starting, had head off exhaust valves badly burnt and seats pitted, had valves and seats re cut and lapped in, compression much better, and starts a bit easier, but now excessive unburnt fuel from exhaust. Had engine out bores honed new set of rings and bigend shells, old ones worn through to copper. I have been told that this is due to fuel getting past rings and into oil. its now rebuilt and has done 30 hours approx. She starts instantly, has loads more power, and revs to 2800 rpm which it never did before in 10 years, sounds wonderful, infact I am very pleased with it except for the smoke from the exhaust, at first I though it might need bedding in and I convinced myself it was getting better, but it is now leaving a far worse oily mess on the transom than before, I am sure it is unburnt fuel, as there is black sooty deposit in the water, could it be the Injectors if not what else could it be. The engine does'nt seem to use any oil now its bedded in. I will have the injectors checked again next week but has anybody any ideas.
Mike www.sailiingforfun.co.uk

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[jleaworthy]

Either too much fuel or too little air IMHO. In view of all you've had done the possibilities are limited on the fuel side to the governor/injection pump. On the air side blocking of inlet filter or exhaust pipe will reduce amount of air available for combustion. It is not unknown for the exhaust rubber tubing to collapse internally whilst still appearing OK from outside. Unfortunately I don't think it's possible to check without removal from the boat.

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[mldpt]

Hi thanks for the reply, if it was one of these do you think she would rev so freely and still have more power than before.
Mike

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[pvb]

Did you get the injection pumps checked?

The 2003 has 3 separate injection pumps. These are calibrated and shimmed when new. If they're disturbed, the pumps and shims must be correctly replaced, otherwise the fuel delivery to each injector will be incorrect. If you have a problem with excess unburnt fuel, it could be the pumps, bearing in mind you've had almost everything else serviced or replaced.

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[mldpt]

Re: Did you get the injection pumps checked?

HI thanks for your reply, No I did'nt but I was very carefull not to Disturb the pumps or the Camshaft that drives them, I took great care when reasembling the govener and timing gear.So feel that these should be OK but it is a thought and I should look into it soon, only thing is the smoke has become more sooty as I run for more hours. I think that I will have the injectors checked next week I suppose it is possible that during one of the several times they were removed and replaces during the rebuild I may have damaged one.
Mike

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[Davy_S]

You have been given some good advise here. I am no expert but i would check the exaust pipe for collapse as mentioned. This happened to me ie smoke, the engine ran perfect but when i removed the hose it was completely blocked.
I was amazed that it could still run!

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[dickhicks]

also had an almost blocked Exhaust Elbow - barely a ½" contorted hole through - check this and the exhaust hose, especially if it is old.

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[mldpt]

Thanks I will check it tomorrow, I had problems last year witht the exhaust elbow and replaced the exhaust pipe but it failed again but as the pipe seemed OK I did not replace it again I suppose the simplist way to check it is to remove it from the elbow and the exhaust box and run water through it.
Mike

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