P0284

Code

LAND ROVER P — Powertrain

Cylinder 8 contribution / balance

Brand: LAND ROVER

Type: P — Powertrain

Views: UK: 26 EN: 59 RU: 31

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Page language: EN

Causes

Faulty or clogged fuel injector (mechanical failure, sticking, leaking)
Open/shorted injector wiring or poor connector contact for cylinder 8
Faulty injector driver / PCM output for cylinder 8
Low or erratic fuel rail pressure or supply (weak pump, clogged filter, pressure regulator)
Low compression, valve train problems, or mechanical damage on cylinder 8
Incorrect camshaft/crankshaft timing or timing chain/belt issues

Symptoms

Illuminated MIL / check engine light
Rough idle or vibration at idle
Reduced engine power, hesitation or surge under load
Increased fuel consumption
Visible smoke (especially on diesel engines) or uneven exhaust note
Possible misfire codes (P0308) or related injector circuit codes (P0208)

What to check

Read freeze frame and live data with a capable scan tool; capture cylinder contribution/balance values and misfire counts
Check for related DTCs: misfires, injector circuit faults, fuel system or cam/crank sensor codes
Inspect wiring harness and connector for injector 8 for corrosion, damage or poor contacts
Measure injector resistance and compare to specification
Monitor injector pulse width and command with a scope or bi-directional tool
Verify fuel rail pressure and inspect fuel filter, pump and regulator

Signal parameters

Injector coil resistance (ohms) — compare to spec in service manual
Injector pulse width (ms) during idle/load as reported by scan tool
Fuel rail pressure (psi / bar) under key-on and engine running conditions
Cylinder contribution / balance % or deviation values from scan tool
Misfire counts for cylinder 8 (events/min or counts per cycle)
Battery voltage (V) during cranking and operation

Diagnostic algorithm

Verify the code and capture freeze frame/live data. Note operating conditions when the code set.
Check for other stored codes (P0208, P0308, fuel system or timing related codes) and address those first if present.
Visually inspect injector 8 connector and wiring for damage, corrosion, pin push-out, or rubbing points; secure grounds and battery connections.
Measure injector 8 resistance and compare to spec. If out of range, replace the injector.
Use a scope or scan-tool to verify injector command and response (pulse width, timing). Look for intermittent commands or missing pulses.
Verify proper fuel rail pressure at idle and under load. Repair fuel supply if pressure is low or fluctuating.
Perform a compression test or leak-down on cylinder 8 to check for mechanical issues. Repair valves/pistons/rings if compression is low.
If mechanical and fuel supply are good, swap injector 8 with another known-good injector and re-run the contribution test to see if the code follows the injector.
Check cam and crank timing alignment and inspect timing components (chains, guides, tensioners, sprockets). Correct timing issues.
If wiring, injector and mechanical checks pass, test the injector driver output at the PCM. If output is faulty, consider PCM repair/reprogram or replacement per factory procedures.
After repairs, clear codes and road-test under the same conditions to confirm the fault is resolved and the monitor completes without resetting the code.

Likely causes

Mechanical or electrical failure of the injector for cylinder 8 (most common)
Wiring/connector fault or intermittent open/short to injector
Low fuel pressure or intermittent supply
Low compression / valve issue on cylinder 8
Timing or sensor synchronization problem affecting contribution monitoring

Fault status

⚠️ Status

Cylinder 8 contribution/balance out of expected range — possible injector, wiring, fuel, timing or mechanical issue. Further diagnosis required.

🟡 Repair difficulty: Medium

⏱️ Diagnostic time: 1.5-4 hours

Repair manuals

Manual library for LAND ROVER

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Browse 413 LAND ROVER manuals: repair procedures, diagnostics, wiring diagrams, component locations, service data and Labor Times by year, model and trim.

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P0284 — Cylinder 8 contribution / balance