Blue smoke is usually caused by oil(knackered engine);injector problems are more likely to cause white smoke.

Makesure you renew the breather valve on the top of the engine & the egr is clear.

Clogged up breather unit makes these smoke blue !

heres a very useful link finally found it

tuning-diesels.com/75Zt/R75faults.htm

Edited by injection doc on 14/03/2013 at 18:07