Hi I have a 2006 freelander TD4 and I lose power when I travel over 50 mph. It does not come to complete stop but the power comes and goes. The amber engine management light comes on from time to time. I have taken it to the garage and they have found nothing wrong with it. They checked everything apart from the ECU. I have sent the ECU off to have it checked but was wondering if this could be a possible fault?. My local Landrover arage said it was the wrong fuel but we have tested it and it is the right fuel. I get black smoke from the exhaust and the engine seems to mis-fire as well. But when I disconnect a pipe in the engine the black smoke stops but I still lose power. Please any help or advice. Thanks guys