TROUBLESHOOTING (Cont'd) Problem | Possible cause | Remedy | Page 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 | FI-58, 63 Incorrect ignition timing | Reset timing | IG-10 Emission control system problem (cold engine) • EGR system always on | Check EGR system | Ignition wiring faulty | Inspect wiring | Fuel system clogged | Check fuel system | FI-44 Air cleaner clogged | Check air cleaner | Fuel system problems | Repair as necessary | Spark plugs faulty | Inspect plugs | IG-5 Engine overheats | Check cooling system | CO-2 Low compression | Check compression | EM-6 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-79 Muffler explosion (after fire) all the time | Air cleaner clogged | Check air cleaner | EFI system problem | Repair as necessary | Incorrect ignition timing | Reset timing | IG-10 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 | FI-58, 63 EFI system problem | Repair as necessary | Insufficient fuel flow | Troubleshoot fuel system | Incorrect ignition timing | Reset timing | IG-10 Carbon deposits in combustion chambers | Inspect cylinder head | EM-18 Excessive oil consumption | Oil leak | Repair as necessary | LU-4 PCV line clogged | Check PCV system | EC-4 Piston rings worn or damaged | Check rings | EM-38