Starts first turn, idles smoothly and revs freely but Smokes under load and the power is well down.

No fault codes. Scoped MAF (seemed OK but tryed another one just to be sure-No diferent)

Am getting a pulse trace from the feedback sensor on injector #4.

Owner has already had EGR valve replaced and new filters/oil change.

Then it got cold and dark!

Any suggestion as to what I should check next?

(Oh, added problem is that Autodata is rather light on information on this model! No wiring/pin diagrams etc! Just to make life interesting!)

Regards Mark.