Mitsubishi 4G64 Engine idle hunts and engine surges above 3,500 RPM when AT is in passing gear
Long term issue. 2002 Engine in a ""Mitsubishi Adventure"" in the Philippines. Just did a complete by the book engine overhaul. Engine idle hunts from 600 to 900 AC off and 800 - 1100 rpm AC on. Also anytime the engine revs above 3,700 RP the engine surges and you feel the car speed up and slow down repeatedly until you drop engine speed. No engine codes at all. All sensors Ohm out per the service manual. Only suspects at this point are the idle control valve and fuel pump. New fuel filter no change... This problem existed before the overhaul.
Dealer tried a throttle body servo 18 Oct and did not correct the problem. Still have the Ignition module, Distributor and FUEL PUMP left in the troubleshooting process. All parts being tried are from known good engines.
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