Stock is 149 hp and 195 ft/lbs torque, not bad for 3.0L and a diesel to boot (this is somewhat more hp than a Chevy Vortec per cc displacement).

I would check the integrity of the boost signal from the manifold to the altitude compensator on the injection pump. The rubber hoses are likely bad by now, and failure to hold pressure will cause low fuel delivery -- as the boost comes up, more fuel is added by the altitude compesator (ALDA for short). It may also need a different shim underneath.

Also, replace both fuel filters, the small in-line clear one and the main "spin on" (actually bolt on). A clogged fuel filter will severely restrict hp output by fuel starvation. If you dont' get some black smoke with it floored at high rpm, this is a distinct possiblity.

Check to see if you still have a trap oxidizer instead of trap catalyst -- the oxidizer is a football shaped thing above the turbo on the passenger side -- if it has been replaced, there will be an insulated exhaust pipe from the rear of the manifold up to the turbo instead. If you still have the trap oxidizer, likely it's shot or plugged, and will be replaced (for free) under warrenty by MB. DO NOT replace it yourself, if the turbo is also bad you get a new one, and a new exhaust most of the time -- something like $4000 worth for nothing.

Stock boost is 13.9 to 14.1 psi.

Do not use propane fumigation, you are very likely to blow the head off from pre-ignition, this is NOT a low compression engine like a cummins or detroit, and the propane will ignite long before TDC on a hot engine if you get a burnable amount in there. Prechamber engines don't do well with propane.

The Finns love these cars, and there is an outfit there that will retrofit your injection pump to produce something like 300 hp (with an intercooler). Way hot for a diesel!

Do not monkey with the timing, you will only lose power or burn the prechambers! Again, this ain't a detuned Cummins, it's a high rpm mechanically advanced MB. There is no electronic control of fuel delivery, so you cannot "chip" it, and I also advise against upping the fuel delivery unless you also increase the airflow -- all you will do is make more black smoke, and power will drop off rather than increase as it goes over-rich.

Check for dragging brakes, especially the rears (pull the pads, clean all the rust out of the slots, and put a little anti-seize on the sides of the backing plate and the cross-spring were it contact the pads). This can cost you lots of acceleration. Fronts don't usually drag without you knowing it, but rears just eat fuel and acceleration.

You should also check the suspension rubber front and rear -- very likely the suspension links at the rear are sagging and need replacement (not a big deal) and the sway bar bushings front and rear are gone as well. If the strut mounts are cracked at all up front, replace those as well, and you probably need rear subframe mounts (I'm part way through this on the 300D). Amazing improvements in handling -- the car is totally immune to crosswinds, I don't even notice them except for wind noise and other vehicles wandering around!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!