Symptoms Diagnosis
Symptom checks cannot be used properly unless problem occurs while vehicle is being tested. To reduce diagnostic time, ensure steps in appropriate BASIC TESTING and TESTS W/CODES articles in the ENGINE PERFORMANCE Section were performed before diagnosing a symptom.
Use diagnostic charts to identify systems and components that should be checked for fault. See DIAGNOSTIC CHART INDEX . Perform check or adjustment procedure indicated in appropriate diagnostic chart.
DIAGNOSTIC CHART INDEX
| Driveability Symptom | See Chart # | |
|---|---|---|
| Starting | ||
| No Crank | 1 | |
| Hard Start/Long Crank | 2 | |
| Stall After Start | 3 | |
| No Start/Normal Crank | 4 | |
| Idle | ||
| Slow To Return To Idle | 5 | |
| Rough Idle | 6 | |
| High Idle | 7 | |
| Low/Slow Idle | 8 | |
| Stalls/Quits | ||
| At Idle | 3 | |
| On Acceleration | 9 | |
| At Cruising Speed | 9 | |
| On Deceleration | 8 | |
| Runs Rough | ||
| At Idle | 6 | |
| On Acceleration | 10 | |
| At Cruising Speed | 10 | |
| Misses | ||
| At Idle | 6 | |
| On Acceleration | 10 | |
| At Cruising Speed | 10 | |
| Buck/Jerk | 9 | |
| Hesitation | ||
| On Acceleration | 9 | |
| Surge | ||
| On Acceleration | 9 | |
| At Cruising Speed | 11 | |
| Backfires | 12 | |
| Lack/Loss Of Power | 13 | |
| Spark Knock (Pings) | 14 | |
| Diesels/Runs On | 7 | |
| Poor Fuel Economy | 15 | |
| Improper Shift | 18 | |
| Emissions Compliance | 16 | |
| Warning Indicators | 17 | |
| Engine | ||
| High Oil Consumption | 19 | |
| Noise | 24 | |
| Runs Cold | 21 | |
| Runs Hot | 20 | |
| Exhaust Smoke | 22 | |
| Fuel Odor | 23 | |
| Vibration | 25 | |