Engine cranks but won't start — diagnostic checklist

Tags: #fuel-pump · #ignition · #immobilizer

This card covers the scenario where the starter does crank the engine but it fails to actually start — distinct from the no-crank-at-all scenarios covered in starter-relay-no-crank.md (thermal relay sticking) and no-crank-rke-relay-harness-damage.md (RKE permission-signal path).

Three common causes, in a sensible check order:

1. Fuel system failure. Check fuel-pump operation and fuel pressure at the rail first — a pump that isn't running or delivering pressure will crank-but-not-start every time.
2. Spark failure. Inspect spark plugs and ignition-coil function if fuel checks out.
3. Immobilizer. If the immobilizer fails its check, the starter will crank normally but the engine gets no spark and the fuel pump won't engage — this can look identical to a fuel or ignition fault at first glance, so don't rule it out just because cranking sounds normal.

Recommended diagnostic order: start with fuel-pump operation and fuel pressure, then spark-plug condition, before assuming a deeper mechanical or immobilizer-specific problem ¹²³⁴.

Related pages

• Pandora alarm — remote engine start feature
• Cold-start hard cranking — LPG and valve clearance
• Fuel pump vs. ignition diagnosis (quick-start)
• Start/Stop button modes and startup sequence
• Front suspension noise diagnostic checklist

Sources

This page is compiled from 4 community messages. Every fact carries a numbered reference to its original author and message.

Last updated: 2026-07-25