In 1998, the BT 5.9 was redesigned as a 24 valve engine to updated emission requirements. ISB stands for Interact System B. The ISB featured a Bosch VP44 rotary injection pump until 2003, when the injection system was upgraded to a Bosch high pressure common rail fuel injection system, which increased power output. In 2001, a high output (HO) version of the ISB became available, which slightly increased the ouput of manual transmission equipped trucks. A 610 version of the ISB became available which pushed torque to 610 lb-ft. Well known for its low speed torque, the Cummins 5.9 ISB has an advantage over V8 diesel engines in the light duty truck market.
359 cubic inches, 5.9 liters
Inline 6 cylinder
16.3:1, 17.2:1 (high output version)
OHV, 2 valves per cylinder, solid lifter camshaft
• Direct injection: Electronically controlled Bosch VP44 rotary injection pump