Engine & warning lights
Car Cranks But Won't Start: A Three-Step Diagnosis
When the starter spins but the engine won't fire, it's fuel, spark, or compression — here's the order to test.
The short version
Relay/fuse $5–32, crank sensor $65–210, fuel pump $160–530, timing belt $320–930.
- 4 symptoms you can check yourself
- 4 diagnosis steps in order
- 2 FAQs answered directly
- Last editorial review: 2026-08-01 · 6 min read
The short answer
- Starter spins normally with no fire-up
- Weak fuel pump or a blown relay/fuse
- Turn the key to ON and listen for the fuel pump priming for two seconds
- Usually low fuel pressure or a heat-sensitive crank sensor.
Background
An engine needs three things: fuel, spark, compression. Strong cranking means your battery is fine; the job is finding which element is missing.
Numbers first: what you'll pay
Relay/fuse $5–32, crank sensor $65–210, fuel pump $160–530, timing belt $320–930.
Figures are a guidance range calculated with a published method — read the methodology.
How to spot it yourself
What actually causes it
- Weak fuel pump or a blown relay/fuse
- Failed crankshaft position sensor — very common
- Unrecognised key or active immobilizer
- Jumped timing belt or chain
Step-by-step inspection plan
- Turn the key to ON and listen for the fuel pump priming for two seconds
- Check fuel and ignition fuses and relays
- Scan for codes — a crank sensor code usually shows immediately
- Try the spare key to rule out the immobilizer
Prevention
Avoid habitually running near empty (it overheats the pump) and keep the timing belt on schedule.
Quick answers
Why does it start after many tries?
Usually low fuel pressure or a heat-sensitive crank sensor.
Is starter fluid useful?
As a diagnostic only — if it fires briefly, your problem is fuel delivery.
DriveMet review
Relay/fuse $5–32, crank sensor $65–210, fuel pump $160–530, timing belt $320–930. Avoid habitually running near empty (it overheats the pump) and keep the timing belt on schedule.
What we verified
- Cross-checked 4 warning signs against 4 likely causes before publishing.
- Reviewed 4 repair steps and confirmed the order a shop would follow.
- Compared the cost range with our published methodology and refreshed it on 2026-08-01.
- Answered 2 questions people actually search for on this topic.
Reviewed by the DriveMet editorial team on 2026-08-01 under our editorial policy. This is an editorial review of the page, not visitor ratings.
Related tools
Apply what you just read to your own car with your own numbers.
Reference sources
- NHTSA vPIC — vehicle specifications and manufacturer recalls
- EPA fueleconomy.gov — reference fuel-economy figures
- SAE J1979 standard for generic (Pxxxx) fault-code definitions
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