Colin I am also a Fixya expert but not in this AOE with regard to specific engines. Engine is installed in a 2002 Mitsubishi Adventure with Auto trans. Vehicle is a Philippine market product. Problem existed before the total by the book overhaul of the engine completed last Thursday. Idle hunts between 700 and 1,000 RPM AC off and 800 to 1,100 AC on. Then during acceleration engine is fine up to around 3,700 RPM when passing then you see the RPM being unstable and not reaching the normal RPM you would see in a passing gear. You also feel the car accelerate and decelerate even without lifting your foot off the accelerator. No engine codes at all. MAP sensor, O2 Sensor, TP sensor and idle control servo all pass resistance and temp checks. The main dealer support center and the factory engineers are also stumped. At this point the repair plan is to swap parts one at a time up to and including the engine computer until the problem is resolved. Any ideas?

Cars & Trucks - Mitsubishi