Bosch MW inline injection pumps were used, which had flyweight governors and vacuum shutoff.

The North American engines had ADA device equipped pumps which limited fuel at high altitudes to prevent smoking with less dense air.

In August 1978 the precombustion chamber was updated to be similar to the new OM617A design for more swirl and more efficient combustion.

September 1979 saw a new camshaft with greater valve lift let air and exhaust gases have less resistance.

[1] In November 1980 the MW style injection pump was replaced with the M type for non-North American engines.

Vehicles sold to the North American market had exhaust gas recirculation equipment fitted.

OM617.931 and OM617.932 This engine was adapted from the .912 to fit the G Class,[3] main difference being oil pan changes.

[4] Modifications for production engines included oil jets to cool the underside of the pistons; pistons with oil passages; stronger connecting rods; sodium filled valve stems and a stronger nitride-hardened crankshaft.

Also an uprated oil pump with separate chain drive was fitted as the turbocharger lubrication required higher flow.

Bosch MW injection pumps were calibrated for greater fuel output and fitted with an ALDA device which prevented overfueling until the turbocharger had begun to provide boost pressure.

[7] The original performance figures for the 2998 cm3 unit were 85 kW at 4200/min[8] and a BMEP of 1.0 MPa,[6] equivalent to a maximum torque of ca.

These engines pre-dated tighter emissions laws, so did not have exhaust gas recirculation (EGR).