Smoke on start up.

[Peasgood]

This is in my Cabstar, but the engine itself came out of a Mistral. It is a 2.7TD mechanical fuel system.
When started from cold it smokes excessively and will not clear until it has been revved past 2500rpm or warmed up. The smoke is from fuel as I can smell it, it also coughs and splutters a bit at the same time. If I go straight up the lane it clears very soon but if I go down the fields slowly (farmer) it is like a steam engine chuffing out smoke.

Any ideas on why, or possible cures?

 

[jims-terrano]

Could be heater plugs not heating correctly. See the download on checking your heater plugs.

Jim

 

[clivvy]

depends on colour of smoke, but also could very well be the injectors? cheap enough on those engines, id check glow plugs as jim says, injectors as thats easy enough then your talking compression issues, timing/injection pumps perhaps.what about the basics, such as fuekl filter? (i doubt its that buy hey, worth checking)

 

[extreme-4x4]

glow plugs like jim said

 

[Peasgood]

Don't the glow plugs only come on briefly for startup?
I thought they went off again after a few seconds.

 

[macabethiel]

glow plug role in diesel engines

My understanding is that glow plugs operate in two ways.

Firstly on cold start-up they are pre-heated for a few seconds and then they are kept warm by the action of the diesel engine heating them up on the combustion/power stroke and then they help re-ignite the next charge of fuel by the tip acting as a ignition spark does in a petrol engine.

If the heater part of the glow plug fails then you get crap starting and your heater plug light remains illuminated for several minutes.

If the tip of the glow plug burns away then it fails to re-ignite the diesel properly so it does not burn cleanly - hence the smoke.

Not sure if this is the same for common rail but I beleive a similar action is involved.

 

[clivvy]

yup, thats it, they continue to run i believe untill the engine reaches operating temperature, or 50 degrees, something like that...!

 

[Peasgood]

Well I didn't know that. Tomorrow I am going to put a test meter on them just to see.