Backfire Diagnostics
NOTE: Backfire is when the fuel is igniting in the intake manifold, or in the exhaust system, making a loud popping noise.
|
Checks |
Action |
|
Preliminary Checks |
N/A |
|
Ignition System Checks |
- Check for proper ignition timing - Check the connection at the ignition coils - Check the resistance (ohms) of the spark plug wires, if any wires have a reading of over 29,000 ohms, replace those wires Remove the plugs and inspect them for any of the below conditions: - improper gap - any and all deposits - wet plugs - cracks - burned electrodes |
|
Engine Mechanical Checks |
Check the engine for any of the below conditions: - sticking or leaking valves - exhaust system leaks - improper valve timing - engine compression - sticking or leaking valves - manifold vacuum leaks |
|
Fuel System Checks |
- Perform a fuel system diagnostics check (Refer to the Fuel System Diagnostics of the manual. |
Table 52. Backfire Diagnostic Table
