TD5 injector problem.

I've had my 02 plate disco es premium TD5 for about 3 years now and with the exception of what seams to be the mandatory leaking factory fit sunroof, its been a great motor.
However, about 6 weeks ago it started chucking blue smoke out the exhaust and running really rough. My local mechanic found all 5 injectors to be well and truly burnt to a crisp! These have been replaced with a set of reconditioned ones but the cause remains a mystery. So far:
1. Dye in the fuel has revealed no crack in the cylinder head and no increase in fluid in the oil sump.
2. The turbo is running at normal pressure.
3. The fuel has been tested and is normal.
4. There is no blockage in the exhaust.

Help! Does anybody have an idea of what could have caused the injectors to overheat because my mechanic is running out of ideas.
Thanks in advance.
APC

Did he take any pics of the old injectors, or do you still have the old ones?
Did you check the normal things? Injector loom, oil in the red plug.
What mileage had they done?
Was it def blue smoke? Blue is a sign of burning oil and shouldn't be an indication of fuel/injector problems.
White acrid smoke is a sign of fuel injector/timing issues, the white smoke is unburt fuel vaporizing in the engine.
Mark

Nah, sorry the old injectors were binned before any pics were taken. I did see them and they were certainly very scorched and misshapen.
It's done 95K with a FSH every 10K (one of the reasons I bought it was the low mileage of about 85K three years ago)
My mechanic seamed to think it was more white smoke than I did (maybe I'm going colour blind!).
I'll ask my mechanic whether he checked the injector loom
Thanks.

I probably misread your first post, did changing the injectors fix the problem or is it still producing white smoke?
Did he re-code the ECU when he installed the "new" injectors?
Mark

Yes the new injectors sorted out the problem and now there is no white / grey smoke and yes the ECU was recoded to the new ones.
The disco runs now but is quite sluggish (in my mechanics words " a snail is quicker"!) but the concern is that the reason all 5 injectors over heated is still a mystery.
Thanks.
Adrian.

Hi Adrian
Thanks for update. Yes its a bit of a mystery.
Poor performance as well, possible turbo/wastegate issues? Over boosting?
Hopefully whatever did in the injectors didnt melt anything else, like a piston?
Mark

My mechanic mentioned something about an air sensor which talks to the ECU maybe faulty which in turn can leads to the wrong fuel / air mix which can cause overheating. Apparently the genuine landy ones are only made by Siemens and the one on my disco is not marked at all. He's going to look at this this week but if that's not faulty then the mystery will remain.