1990 Isuzu Trooper Service and Repair Manual

Late in the first generation, the 1990 Trooper offered two engines: a 2.6L SOHC inline-four and a GM-built 2.8L OHV V6. Most were four-door models in S, XS or LS trim, alongside a short-wheelbase RS two-door. Part-time four-wheel drive and a boxy, upright body defined the truck. This service and repair manual is matched to the 1990 Trooper, with procedures, specifications, torque values, wiring diagrams, diagnostics and maintenance schedules for both engines and the four-wheel-drive system.

Engines covered

• 2.6L inline-four — SOHC, naturally aspirated, gasoline
• 2.8L V6 — OHV, naturally aspirated, gasoline

Body styles covered

• 4-door sport utility
• 2-door sport utility

Trims covered

• LS
• RS
• S
• XS

Known issues on the 1990 Trooper. Three recalls are on federal record. They cover an oil cooler hose that can be installed where it touches and melts on the exhaust manifold, automatic transmissions overfilled with oil that can seep onto the exhaust manifold when hot, and a trailer hitch receiver weld that can break. NHTSA has also logged 34 owner complaints, most often about the engine and cooling system and the powertrain. Correct fluid levels, hose routing and hitch torque values are all in the manual.