Diagnostic Aids
WARNING: This page is about a different car, the 2000 Isuzu VehiCROSS, 2000 Isuzu Trooper, 2000 Isuzu Rodeo, 2000 Isuzu Amigo, and 2000 Honda Passport. However, it is still accessible from the selected car via links, so may be relevant.
Scan tool message MISFIRE CUR. #1-6 is helpful for determining if only a single cylinder is affected by misfire. Check ignition coil for cracks or damage. Substitute a known-good ignition coil. Numerous short trip drives (under 3 miles), may fuel foul spark plugs and set DTC. If DTC cannot be duplicated, check scan tool FAILURE RECORDS to determine mileage since last DTC was set.
If misfire is random, inspect all system grounds. Check for low fuel pressure or lean injector(s). Perform fuel pressure test and injector balance test. See SYSTEM & COMPONENT TESTING article. Check for fuel contamination, vacuum leaks at air inductions system or EGR system.