series 3 2 1/4 diesel smokin

Hi after some advice I have a 2 1/4 diesel it seems to smoke black smoke with any acelleration once at a crusing speed smoke stops but if you put your foot down again it smokes black smoke again. When going up hills or when the engine seems to be under strain it seems to smoke.
The engine does not smoke on startup.
I did remove the exhaust manifold the other week and found it to be quite oily and I would not have expected this.

Has any body had this problem

The problem is almost certainly OVER-FUELLING.

Over fuelling means more diesel is being injected than there is air getting in to burn it. This could be too much fuel or not enough air.

The very first thing to do is to make SURE that your engine air filter and inlet hoses are clean and in good order.

You must make sure none of the air inlet hoses are suffering inside, and going flat when driving, or flaps loose inside hoses causing blockages. It happens.

The test to undertake is to REMOVE the air filter element and take the car for a drive. In a 2¼ diesel you can just take off the hose from the manifold and go for a run. It will be noisy .... If the black smoke stops then a clean air filter is called for. If not, it's Plan B next.

Assuming the engine is getting all the air it needs, the MAXIMIUM FUEL needs turned down a little, but whether you can do this depends on the pump type you have. It could be a Lucas CAV type DPA or DPS. Which? many of these pumps have the max fuel pre-set inside them and it's hard to alter them.

Remember, because it's a diesel, adjusting the THROTTLE arm back will NOT reduce maximum fuel flow - it will only cut down the maximum REVS, and in a 2¼ diesel you definitely need every last rev you can find.

Let me know which pump you have.

CharlesY

Hi Chaeles Thanks for your reply my injection pump is a DPA type with the external timimg pointer. I am going to try with air filter removed tonight.

stedsy said:

Hi Chaeles Thanks for your reply my injection pump is a DPA type with the external timimg pointer. I am going to try with air filter removed tonight.

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Good plan.

It would be highly unusual for the internal maximum fuel setting to "slip" further open, so we should eliminate all simple possible causes first.

While you are about it, make sure your engine breather cap is clean and the hose isn't choked up.

CharlesY

Charles I removed air filter hose and went for a drive I could not notice any difference in the amount of smoke. Checked breather cap and hose all seems ok. I did mention in my 1st post aout the exhaust manifold and inlet manifold being oily would this mean ring &bores worn or would this be a blue smoke ???

stedsy said:

Charles I removed air filter hose and went for a drive I could not notice any difference in the amount of smoke. Checked breather cap and hose all seems ok. I did mention in my 1st post about the exhaust manifold and inlet manifold being oily would this mean ring &bores worn or would this be a blue smoke ???

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It would be blue smoke if it was a little engine oil coming past the pistons or down valve stems, but you were talking about lots of BLACK smoke when you give it the welly. Right? That does suggest excess fuel.


One other possibility is that lots of engine oil is being blown out of the breather pipe and into the inlet manifold when you put your foot down, and making black smoke. Crankcase pressurisation can cause this, like worn rings and so on, but you would notice it using a lot of engine oil.

Take the breather pipe off the manifold, and tape it on to a plastic milk bottle so it "breathes" into the bottle. The bottle will need a hole near the top to let fumes out.

Get the engine warmed up and take it for a run and use full welly as much as possible. A few minutes of this and you'll know if it's blowing heaps of oil into the bottle.

It's a question of easy simple tests to enable you to diagnose the problem, basically by eliminating possibilities one by one.

My top favourite is still over fuelling. The DPA injection pump is fitted with an EXCESS FUEL DELIVERY SYSTEM as a starting aid. This should set itself whenever the engine stops (hot or cold) and UNset itself when the engine fires up. Let's hope this isn't stuck ...

Have you tried a bottle of diesel cleaner stuff? Some folk swear by it.

CharlesY

Try some 'Millers" diesel additive.

I will try some injector cleaner at the weekend thanks.

I have connected a bottle to the end of the breather pipe and went for a drive with plenty of welly there seems to be no breather problem as no oil in bottle.
I tried some injector cleaner in the engine, I filled the fuel filter with it and took it for a run it seems to go a bit better now but it still smokes the same under acceleration.

It MUST be one or other of too much fuel or not enough air.

You MIGHT make an improvement by advancing the injection timing as far as you can without inducing diesel clatter.

The effect of this is to allow more TIME for the fuel to burn.

This only works if the injection timing is retarded now - which is usually caused by wear and tear in all the bits and pieces that drive the injection pump.

Try advancing to pump in 2mm stages and see what happens.

Remember to slightly slacken the injector feed pipes at the pump end before you turn the pump.

This might make all the difference, AND the car will pull better if you get it right.

CharlesY