Hi. My E320cdi, Chassis starts WDB2100, will not rev above 3000 at all when cold with very slow build up of power then for no reason it will pull like it should but with lot of black smoke initially then after a while it will return to no power, no smoke, then back to full power and so on. Valve on inlet manifold been changed by Mercs and they show no faults on computer BUT fault is there. Hope someone can help?? eltomo.

 

Could be an intermittent fault with the air mass flow sensor. I had a failed sensor and it gave the loss of power you describe. If it comes back on you would get a burst of fuel and the black smoke you describe.