Operation Section 60 Problem Probable Cause Corrective Action Engine Stalls Fuel Lock-off malfunction Repair/replace Fuel Lock-off z See Engine Service Manual Faulty vapor connection between the pressure regulator/converter and the mixer Check connection z Verify no holes in hose z Clamps must be tight z Look for kinked, pinched and/or collapsed hose Pressure regulator freezes Check level in cooling system z Must be full, check coolant strength z -35F minimum z Check coolant hoses z Watch for kinks and/or pinched hoses z Verify one pressure hose and one return hose Pressure regulator malfunction Test pressure regulator operation z See Engine Service Manual Vacuum leak Check for vacuum leaks z Between mixer and throttle body z Between throttle body and intake manifold z Between intake manifold and cylinder head Air/Fuel Mixer malfunction Check mixer z See Engine Service Manual Engine Mechanical See Engine Manufacturers Service Manual Rough Idle Faulty vapor connection between the pressure regulator/converter and the mixer Check connection z Verify no holes in hose z Clamps must be tight z Look for kinked, pinched and/or collapsed hose Pressure regulator malfunction Test pressure regulator operation z See Engine Service Manual Vacuum leak Check for vacuum leaks z Between mixer and throttle body z Between throttle body and intake manifold z Between intake manifold and cylinder head Air/Fuel Mixer malfunction Check mixer z See Engine Service Manual