Cylinder 4 Contribution/Balance Fault
Cylinder 4 fuel injector is delivering insufficient fuel, causing reduced power and rough idle. The injector may be clogged, failing, or spraying poorly.
What You Might Notice
- Check engine light on
- Reduced power and acceleration
- Rough idle
- Drop in fuel economy
- Misfiring in cylinder 4
Most Common Causes
- 1
Clogged fuel injector
Carbon buildup prevents proper fuel atomization in cylinder 4.
- 2
Failed fuel injector
Injector coil or internal components are damaged or stuck open.
- 3
Low fuel pressure
Fuel pump or regulator failure reduces pressure to all injectors.
- 4
Faulty injector wiring
Corroded connector or damaged wire prevents proper injector operation.
How to Diagnose It
- 1
Check Clogged fuel injector — Carbon buildup prevents proper fuel atomization in cylinder 4.
- 2
Check Failed fuel injector — Injector coil or internal components are damaged or stuck open.
- 3
Check Low fuel pressure — Fuel pump or regulator failure reduces pressure to all injectors.
- 4
Check Faulty injector wiring — Corroded connector or damaged wire prevents proper injector operation.
How to Fix It
- 1
Clean fuel injector
Use fuel system cleaner or have injector professionally cleaned or soaked.
- 2
Replace fuel injector
Install a new or refurbished injector on cylinder 4.
- 3
Check fuel pressure
Test fuel pump and regulator; replace if pressure is low.
- 4
Inspect injector wiring
Check connector, harness, and ECU connections for corrosion or damage.
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