ENGINE SYMPTOM TROUBLESHOOTING [L8, LF]

id0103a0800300

• Confirm trouble symptom using the following diagnostic index, then go to appropriate troubleshooting chart.

Diagnostic Index

No. | TROUBLESHOOTING ITEM | DESCRIPTION
--- | --- | ---
1 | Melting of main or other fuses | —
2 | MIL illuminates | • MIL is illuminated incorrectly.
3 | Will not crank | • Starter does not work.
4 | Hard to start/long crank/erratic start/erratic crank | • Starter cranks engine at normal speed but engine requires excessive cranking time before starting. (The battery is in normal condition.)
5 | Engine stalls | After start/at idle | • Engine stops unexpectedly at idle and/or after start.
6 | Cranks normally but will not start | • Starter cranks engine at normal speed but engine will not run. • Refer to symptom troubleshooting “NO.5 ENGINE STALLS” if this symptom appears after engine stall. • Fuel is in tank. • Battery is in normal condition.
7 | Slow return to idle | • Engine takes more time than normal to return to idle speed.
8 | Engine runs rough/rolling idle | • Engine speed fluctuates between specified idle speed and lower speed and engine shakes excessively. • Idle speed is too slow and engine shakes excessively.
9 | Fast idle/runs on | • Engine speed continues at fast idle after warm-up. • Engine runs after the ignition switch is turned off.
10 | Low idle/stalls during deceleration | • Engine stops unexpectedly at beginning of deceleration or recovery from deceleration.
11 | Engine stalls/quits | Acceleration/cruise | • Engine stops unexpectedly at beginning of acceleration or during acceleration. • Engine stops unexpectedly while cruising.
Engine runs rough | Acceleration/cruise | • Engine speed fluctuates during acceleration or cruising.
Misses | Acceleration/cruise | • Engine misses during acceleration or cruising.
Buck/jerk | Acceleration/cruise/deceleration | • Vehicle bucks/jerks during acceleration, cruising, or deceleration.
Hesitation/stumble | Acceleration | • Momentary pause at beginning of acceleration or during acceleration.
Surges | Acceleration/cruise | • Momentary minor irregularity in engine output.
12 | Lack/loss of power | Acceleration/cruise | • Performance is poor under load (such as power down when climbing hills).
13 | Knocking/pinging | Acceleration/cruise | • Sound is produced when air/fuel mixture is ignited by something other than spark plug (such as hot spot in combustion chamber).
14 | Poor fuel economy | • Fuel economy is unsatisfactory.
15 | Emission compliance | • Fails emissions test.
16 | High oil consumption/leakage | • Oil consumption is excessive.
17 | Cooling system concerns | Overheating | • Engine runs at higher than normal temperature/overheats.
18 | Cooling system concerns | Runs cold | • Engine does not reach normal operating temperature.
19 | Exhaust smoke | • Blue, black, or white smoke from exhaust system.
20 | Fuel odor (in engine compartment) | • Gasoline fuel smell or visible leakage.
21 | Engine noise | • Engine noise from under bonnet.
22 | Vibration concerns (engine) | • Vibration from under bonnet or driveline.
23 | A/C does not work sufficiently | • A/C compressor magnetic clutch does not engage when A/C is turned on.
24 | A/C is always on or A/C compressor runs continuously | • A/C compressor magnetic clutch does not disengage.
25 | A/C is not cut off under wide open throttle conditions | • A/C compressor magnetic clutch does not disengage under wide open throttle.
26 | Exhaust sulphur smell | • Rotten egg smell (sulphur) from exhaust.
27 | Spark plug condition | • Incorrect spark plug condition.
28 | AT concerns | Upshift/downshift/ engagement | • AT concerns not related to engine performance.