White smoke from cold 2.25 Diesel

Hello,
I am new here and have searched the forums for a solution to my smoke issue - to no avail! Can anyone help?
I have a 1978 Lightweight diesel LHD (ex Dutch army 24v). It’s in great shape having only done some 76km miles. When the engine is up to temperature it runs very well indeed with only a small amount of black smoke on hard acceleration.
But from cold starting, till it’s at normal running temperature, I get lots (embarrassing amounts) of white smoke. The white smoke is worse at normal driving speeds and all but disappears when de-accelerating or accelerating hard.
Once the engine is hot, the problem vanishes!
I keep the landrover up in the hills at 3000 feet. But the problem still exists at lower levels.
Anyone got any thoughts? Or has this been covered in another thread?
Thanks for your help.

White smoke is air in the fuel....you have a leak somewhere.

Ah! OK will check. But what I don’t understand is why does the smoke then disappear when the engine is up to temperature!

First thing. White smoke on a series is generally unburnt fuel. It mostly happens when there are timing issues.

Listen to it on tick over. Does it chuff now and then. Sounds like a slight miss, rather like a steam engine. If so firstly check your valve clearances and check for smoke and the chuff again.
If no improvement you may have to loosen the bolts holding the fuel pump down and rotate it slightly to set the timing. There should be a small pointer on the engine block next to the front pump retaining bolt. This bolt is in a slot. Unfortunatly there are no marks on the slot so with the aid of a pencil or tipex or a nail you have to mark its position and turn the pump about 1mm, tighten the bolts and then see how its running. Eventually you will get an improvement. Each time you move the pump its advisable to loosen the high pressure pipes that lead to the injectors then re tighten so as not to strain them.

Sometimes all the play has already been taken up on the pump slide. Some people take it off and make the slot longer (you can usually guess this if the bolt is already tight at one end of the slot). In such cases your better off changing the timing chain as very often its at the end of its useful life and has stretched and worn beyond saving.

There are other things it can be but usually its the timing and very easy to adjust. Its just a PITA taking the time to do it. Worth doing though as a well tuned diesel is as sweet as a nut.

JackLill said:

Ah! OK will check. But what I don’t understand is why does the smoke then disappear when the engine is up to temperature!

Click to expand...

white smoke is unburnt fuel caused by poor timing ie too retarded as chain and parts wear,
low compression which will improve when engine warms up,can be poor injectors to but id suspect its probably both of the first 2

This page is informative on the topic!

I would agree...retarded pump timing...you sure its white....and not blue mixed with condensation at this time of year.

Nick.

First thing I would do is fit a new fuel filter, fueling issues with diesels I always fit a new filter first unless the problem cause is obvious.
If it were air in the system it would be missing as well usually,
Did this problem happen suddenly or did it creep up over time?

If it is truly OK once warmed up, them maybe not something to be too concerned about? When cold it is understandable that there will be some unburnt fuel - but I don't know what is normal for those engines. Mine (perkins) produces huge white smoke on cold start, which mostly goes away, but the fumes remain quite strong, so this thread on the causes is interesting. I really want to adjust timing etc, but it is currently working and I don;t want to upset it.

These (I too have a Perkins) engines are pre-chamber designs so the combustion chamber is slow to heat up. Watch an old digger or loco start, its the same. Clean injectors will help as they produce a finer spray that is easier to ignite. Dirty injectors make droplets that stay on the cold chamber sides. I would run some injector cleaner through for a while and see if it helps. Simple and doesn't cost much.