My 1992 4.2ltr petrol shorty patrol misfires under load.
This is most noticeable at 2000 to 2400 RPM in overdrive or whilst accelerating when towing without overdrive and continues right through to 4000 RPM.
The problem can be non evident upon cold start but becomes more apparent as the engine increases in temperature.
Occasionally the engine will back fire on LPG but the misfire problem is constant regardless of fuel type (LPG/Petrol).
The engine has done 180000 K's and the valve clearances are fine.
All advice is welcome.
Regards hillyandco