VT, if you haven't already guessed Vasco doesn't like these engines. However, since we both have them fitted in our boats then we wil have to make the most of it.
I notice your in London and with air temperatures in single
figure (centigrade) then its tough on an engine without a cold start. The quick way to start them is with a squirt of easy start, but don't go OTT with the stuff.
There are some other things you can check, on the side of the engine were the throttle cable joins the engine, does the throttle open fully? and does the engine stop cable work fully. You probably need two people to do this, one to move the levers and one to look at the engine. Next if you are feeling brave is to take side cover off the box the cable levers attach to. Unfortunately I don't have the access to do this without removing the engine on my boat. Inside is a series of springs, clips and widgets which move the fuel rack forward to increase the amount of diesel
injected on each stroke. Anything broken or worn in here isn't going to help.
Final thought is when was the last time the engine injectors were pulled and tested for the spray pattern? be warned that they live in a copper jacket which seals
them from the engine coolant
in the cylinder head
. If you are not careful taking the injectors out the copper jacket comes out too and that is a head off job to replace them, if you can buy them as they are getting rare. Deciding against this when I changed the fuel filter
last year I did a 50/50 mix with diesel
and injector cleaner to clean out the 3 x FIPs and injectors. Worked a bit so will repeat again this year.
When was the last time the tank was cleaned out? muck (diesel bug) in there blocks the fine mesh filter in the older type of fuel pumps which won't help starting.
Final thought, when was the air filter last cleaned? the process is in the manual available from the Volvo Penta
Website or Blue Moment forum, but it involves soaking in a bath of diesel, the filter is a wire mesh inside the metal canister and can't be opened up. The alternative is to fit a £30 K&N filter and do away with the volvo one. K&N have general purpose filters for engines not on their popular lists.
It is never going to be easy to start them in cold weather
but the above might it might help.