hi, d90 1987 200tdi conversion two years ago, right, driving along building up the revs to change to third and I'm getting an intermittent power loss on the pedal, change to third build power up to change to fourth same again, also same in fourth when up to power, on inspection I found that the small pipe that comes off the airflow meter to fuel pump was melted to manifold with a hole in it, changed the pipe with new, but still got the same problem first thought it was water in fuel checked filter all clear, I then pulled the rubber hose off that fits to the airflow meter and I could see a slight oil on the connector, also there isn't so much power in truck as normal, any ideas dd.