TROUBLESHOOTING (Cont'd) Problem | Possible cause | Remedy | Page Rough idle, stalls or misses (cont'd) | Spark plugs faulty | Inspect plugs | IG-7 | Engine overheats | Check cooling system | CO-4 | Low compression | Check compression | EM-20, 21 Engine hesitates/ poor acceleration | Vacuum leaks • PCV hoses • EGR valve • Intake manifold • Air intake chamber • Throttle body • ISC valve | Repair as necessary | | Pulling in air between air flow meter and throttle body | Repair as necessary | | Incorrect ignition timing | Reset timing | IG-20 | Emission control system problem (cold engine) • EGR always on | Check EGR system | EC-12, 16 | High tension cord faulty | Inspect cord | IG-6, 11 | Fuel system clogged | Check fuel system | FI-70 | Air cleaner clogged | Check air cleaner | MA-5 | EFI system problems | Repair as necessary | | Spark plugs faulty | Inspect plugs | IG-7 | Engine overheats | Check cooling system | CO-4 | Low compression | Check compression | EM-20, 21 Engine diesels (runs after ignition switch is turned off) | EFI system problems | Repair as necessary | Muffler explosion (after fire) on deceleration only | Deceleration fuel cut system always off | Check EFI (fuel cut) system | FI-124 Muffler explosion (after fire) all the time | Air cleaner clogged | Check air cleaner | MA-5 | EFI system problems | Repair as necessary | | Incorrect ignition timing | Reset timing | IG-20 Engine backfires | Vacuum leak • PCV hoses • EGR valve • Intake manifold • Air intake chamber • Throttle body • ISC valve | Check hoses and repair as necessary | | Pulling in air between air flow meter and throttle body | Repair as necessary | | EFI system problem | Repair as necessary | | Insufficient fuel flow | Troubleshoot fuel system | | Incorrect ignition timing | Reset timing | IG-20 | Carbon deposits in combustion chambers | Inspect cylinder head | EM-32