I feel stupid for finding this was the problem ,replaced fuel filters and cleaned the banjo bolt at the aluminium air port but it didnt make a difference so as I was about to pull the tank to look at the screen I realized the most basic need of the diesel was its linkage con rods being well lubed.I bought some good lithium spray and it responds good as new..I had an issue once before on a linkage peice that seems to wear out over age ,it resides on the firewall but this I knew was not the issue,well goes to show if you start with the small stuff first it makes life so much easier.

Ditto. I replaced the ball pivot on the firewall + cleaned and lubed all the linkage pieces after I got them tightened up to where they don't have any slop/play. New tank screen and new filters makes a whole world of difference on these cars.

__________________
current vehicles:
'82 240D - 125k - daily driver
'85 380SE - 299k - on dry dock
'87 Vanagon - 183k - sold