reduce smoke

[barkster1971]

My car has failed it's mot because it's too smoky. How can I get it blowing clearer exhaust gases out the back end?

[ngoma]

Is it the condition you described in this thread?

https://d24t.com/showthread.php?t=2362

[barkster1971]

No , that issue has been sorted, this is too smoky when revved up.

[ngoma]

Black smoke?

[barkster1971]

When I accelerate hard its chucking out black smoke, which is how the test is done. Is there enrichment when accelerating?
Turning down the fuel screw a bit help?

[ngoma]

The extra fueling corresponds to boost level, computed in the "flying saucer" on the top of the D24T IP.

Before going there, do you know if someone may have messed with the fuel screw? If so, then you can help lessen the excessive soot by backing the screw out to a more reasonable setting.

MY SUGGESTION: Start with 1/4 turn adjustments. TAKE NOTES so you can easily return to a good setting if problems arise. When you are getting close make 1/8 turn adjustments.

If you go too far it may not idle or even start, lack power, etc. Too far in and you get excessive soot, high idle, possible runaway, engine damage, poor fuel economy.

If this doesn't do it then we can look at the star wheel in the LDA.

What condition is the air filter?

[barkster1971]

I've backed off the fuel screw quite a bit. It's only only hard acceleration and it's not too bad. I've also put in v power diesel. The retest is tomorrow. Is there a limit to how much I can back off the fuel screw?

[ngoma]

Originally Posted by barkster1971

Is there a limit to how much I can back off the fuel screw?

Yes, that's why I recommended keeping a log of the changes, so if you encounter problems you can easily get it to the last good setting.

Curious: how many turns have you turned it out? Did it affect the idle?

Too far out you could get hard start/no start, poor idle/no idle, low power, etc.



What is v power diesel?

[barkster1971]

The turbo is original from 1984, it's knackered and weeping oil through the intake hence the black smoke on boost /

[ngoma]

Huh, interesting. I would have thought burning oil should be more blue?