1972 220D 4 speed manual with later model 240D engine swapped in. Unknown miles.

Motor runs smooth, starts first thing in the cold. Have not checked compression but the motor does not consume much oil. On par with my 82 240D that is much quicker. Burns about 1qt / 1500-2000 miles. Motor has excellent oil pressure. It's basically at about 3.5 bar at hot idle coming off the highway. I'm presuming the motor is in great shape.

The throttle linkage has lots of slop, but when I have someone floor it inside the cabin, all the slack is taken out in the engine bay.

One thing I've noted is that the throttle linkage does not reach the full throttle stop on the injection pump. Even if I disconnect all the links and move just the injection pump arm, it does not reach the full stop. Also the injection pump won't let me manually shut the motor off.

Whats been done:

- New fuel lines (no air leaks)

- New fuel filters

- Tank removed and power washed out, screen removed and cleaned

- Injectors replaced with known good units from another 240D

- New air filter

- valves checked and all within spec, motor oil and filter changed( not that that part would matter)

Symptoms:

Absolutely glacial acceleration in comparison to my 82 240D AUTOMATIC. I would assume the w123 with automatic trans is a heavier car and therefore slower. That car has about 165k miles on it.

Car struggles to climb hills in 3rd gear and will lose speed on the highway in 4th cruising around 65/70 at the slightest incline.

Checked brakes and none are dragging. I'm stumped as to what could make this car so slow. I thought the 4 speed would make it a touch peppier than the auto w123. It is noticeably slower.