Diesel engine a pain to start

[SimonA]

My BMC 1.5 diesel is a right pain to start, cold or hot. I have to crank it over for ages before it even breathes any sign of life, hen it takes another 2 or 3 20 seconds attempts to get it to start. When it does start the throttle has no effect for about 20 to 30 seconds, the engine just idles away even with the throttle fully open.

Once it's warmed up I can switch off and back on and it will be fine. But if I leave it for any longer than 10 minutes it will be very difficult to start again.

It was fine last year, but has been like this since the start of the season.

A boatyard looked at my filters and said I had diesel bug. I have since changed the filters, treated the tank with Fuel Set and taken on 60 litres of clean diesel to mix with about 30 litres of the old diesel. None of this has made any difference.

When it does start I get a cloud of smelly smoke which is grey in colour. This soon goes.

 

[alb40]

A couple of things check:

1. Ensure all traces of bug are gone in filters and lift pump, and make sure there are no air leaks.

2. Check glow plugs are working. May pay to change them, and see what happens. You should have these on for at least 30 seconds prior to engaging the starter with these engines.

It may also be beneficial to have the injectors cleaned and checked incase the bug bunged them up. This could explain the hot starting issue. Its a fair bet that a blockage or air leak into the fuel is causing the problem.

Hope that helps
Alex

 

[scottie]

the space round the glow plugs may have carboned up
try a search for this on eonarlier post here

 

[moody1]

Friends of ours had all filters, lines and tank cleaned and still had trouble. Finally it was found that the small filter inside the main inlet of the injection pump was blocked. This is an item rarely mentioned and even rarer checked. When we heard about it - HWMBO had ours lifted and sure enough we had 50% blockage of same small filter.

 

[SimonA]

Thanks for the suggestions. Sounds like it might still be the bug giving my grief.

 

[harvey]

As already said, Glow plugs would be my starting point. Make sure that they are all getting to heat up. I had a similar problem on a Westerbeke engine and eventually discovered that the contacts for each of the glow plugs were slightly corroded which providing resistance. I took them off, cleaned them with fine wet and dry and the engine was good afterwards.
Good luck
John

 

[bromleybysea]

FWIW, I had very similar symptoms years ago on a Volvo 2003- turned out to be the anti-siphon valve in the water inlet had failed so water was being drawn back into the engine as it cooled after stopping. Might be worth checking.

 

[FlyingDutchman]

I don't think the glow plugs are the problem: The engine also starts difficult when warm. Suerely, you don't have to preheat a warm engine?