Three things cause power loss.
1. Linkage adjustment/placement.
2. Valves adjusted too lose/wrong valve lash... I.e. Intake valve got exhaust setting and vice versa...
3. Turbo/Alda line dislodged.
Also, if it's been a while, fuel filters clogged can seriously slow down the vehicle.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!