W123

I just purchased this car. It starts quickly and idles smoothly but has no power and will only go about 30 on flat ground. I removed exhaust pipe with the cat and muffler, thinking the cat was plugged, didnt help. the previous owner said the turbo got hot and caught the underhood insulation on fire but he got it out quickly and with the exception of 2 vacumn lines it didnt hurt anything. turbo area emits a highpressure air sound, not a turbo whistle,at idle and it gets louder under power. Any suggestions? Thanks Tom Postscript 1st benz Ive owned so have to catch up.

Our 1979 300D runs great at speed. We just installed Kent's boost pump kit and it really does help starting and idling and did help a little on power too. I was hoping it would also solve our shifting problem as well but it did not. From a dead stop, the car will always start rolling in second gear (which as everyone knows makes it painfully slow) even if I mash the pedal down. It will do this even if I shift into neutral while stopped then shift to drive just before moving.
We've already done the following to this car: recent valve adjustment, timing chain replaced (has good timing now), recent diesel purge, new filters, fuel lines and fuel strainer, adjusted kickdown rod from throttle to transmission (which did improve the shifting above 20mph to earlier shifts for more power).