Poor acceleration 1985 300tdt

[rogersherwoodki]

Mercedes 300 tdt 1985 with automatic transmission.

This new old car has very slow acceleration especially when cold until about 30 or 35 mph and 2200 rpm where turbo must kick in because RPM picks up quickly and car accelerates well. Takes about 14 or 15 seconds to get to 60 mph so performance seems reasonable as long as it is being asked to accelerate the most. But at about 40 mph, car wants to slow down unless enough throttle is used to kick in turbo. Makes for a surge like ride for in town driving since can’t accelerate slowly – either almost not at all or fast with the turbo. Measured pressures are 17 in Hg vacuum and 12 psi pressure during acceleration peaking at about 14 momentarily during a shift. Would appreciate any suggestions.

Roger