Chart 11
WARNING: This page is about a different car, the 2004 Ford Pickup Heritage. However, it is still accessible from the selected car via links, so may be relevant.
Spark Knock
NOTE:
If the following test fails to correct the condition, it is recommended that the owner change the source of fuel. Ensure the proper grade of CNG fuel is being used.
| SYSTEM/COMPONENT | REFERENCE (PINPOINT TEST - BI-FUEL CNG unless noted) |
|---|---|
| Verify engine operates at normal temperature | Visual (refer to STEP 2: NO DTC(S) PRESENT SYMPTOM CHART INDEX to diagnose any cooling system concerns that are present). |
| Base Engine | Refer to appropriate ENGINE article. |
| Fuel Delivery System | GO to Pinpoint Test HC . |
| Secondary Ignition | Refer to INTRODUCTION - CNG, FLEX-FUEL & GASOLINE . |
| Knock Sensor (KS) | Refer to INTRODUCTION - CNG, FLEX-FUEL & GASOLINE . |
| PCV System | Refer to INTRODUCTION - CNG, FLEX-FUEL & GASOLINE . |
| Engine Oil Quality | Visual. |
| Mass Air Flow MAF Sensor | Refer to INTRODUCTION - CNG, FLEX-FUEL & GASOLINE . |