TAMD41b starting probs

[Elza_Skip]

Suggestions from the assembled wisdom sought!

The last couple of times going down to the boat the port engine has been reluctant to start- spinning over without firing for some while then after a few of tries and some throttle added it starts and runs fine. For the rest of the time I am at the boat it starts OK

Historically both engines start very well, even after a long break.

Some areas I am thinking of:

Firstly fuel but when running the engine delivers full power as normal

Air- but engine does not even attempt to fire to start with, not like the rough running and fading out I have had with airlocks before

Engine stop solenoid- I think I have heard that these can stick

Thoughts from the collective?

 

[Duster]

Almost certainly some air is getting into the system, or the fuel is draining back to the tank, when it is stood for log periods. One of our tractors did that trick for a while.

Check the seals on the fuel filters and fit new ones CAREFULLY, espescialy if there is one fitted to the center bolt which holds the unit together. I am not certain which filters your engine has but I have seen lazy / incompetant grease monkeys not replace this seal, even occasionally not change the main rubber ring seal and one one occasion, fitting a new ring without removeing the old one.

Note; warm the engine up first, it is much easier to bleed and restart a warm engine.

If that does not fix it, check the lift pump, particularly the suction side, for air leaks.

Regards mikej

 

[pappaecho]

Agree it sounds like a classic air problem, which is only purged after excessive cranking. I would check lift pump diaphragm, filter seals, if changed recently, and then pipework from tank to injector pump

 

[OAF]

I had same problem on my old ad41,s turned out to be a partial blockage in d fuel supply pipe from tank to lift pump, took ages of cranking to get started; I's your engine White smoking while you are cranking it ?

 

[DAKA]

Do the modern 41's still have diesel heaters ?

My old ones 1988, had two heaters for each engine from memory.

They are on the top (look a bit like a spark plug).

Turn engine on until glow light comes on or if you dont have a glow light just crank for a while and as soon as it starts turn it off, if it doesnt start thats even better for this test.

now simply put your finger on the glow lug which should be warm/hot to touch and everything else is still stone cold.

If they are also cold then replace the glow plug and test again.

Putting a fan heater directed at the top of the engine for 1/2 hour is a temporary solution to dodgy glow plugs.

I would have expected a little extra smoke at start up with dodgy glow plugs but I dont suppose its that easy to tell with 41s.

 

[Duster]

Good points, no smoke - usually means no fuel - usually means air leak.

 

[Elza_Skip]

Thanks all,

Just a few answers to the questions asked..
I do not think it is smoking while cranking until the engine fires. Considering the amount I cranked it there was not noticeably more smoke than usual but cannot say I looked out for it
The 41bs were not normally fitted with glow plugs and mine definately does not have them otherwise that would be a good place to start
I have not disturbed any part of the fuel system recently
The partial blockage in the supply side sounds a possible, but I would have thought this would manifest this more under load?
Air getting in- I will have a good look around all the connections to make sure they are sound next time I am down.

 

[Elza_Skip]

One other thought I have had- could the fuel be back siphoning into the tank when the engine has been at rest (presumably due to air getting in)? This would explain why the problem only appears after the boat has been left a week....

Having said that there is a solenoid valve on the tank that shuts off when the ignition is off

 

[Duster]

One other thought I have had- could the fuel be back siphoning into the tank when the engine has been at rest (presumably due to air getting in)? This would explain why the problem only appears after the boat has been left a week....

Highy likely, I have had this several times and it was my first suggestion. Air ( suction leaks are more difficult to trace than pressure / fuel leaks for obviose reasons. It may be a case of replace the filter seals and check that all the fuel pipe compression joints are tight.

It is possible that the solenoid valve has failed and stuck open or partially open.

By "smoking" I meant does white smoke (unburnt fuel) come out of the exhaust BEFORE the engine fires up? Smoke once it is running is not really relevant to this problem.

mikej