Cliff: Created page with "'''No-start diagnosis''' is an overview of diagnostic steps for a Pontiac Fiero that cranks but does not start, or does not crank at all. No-start problems can be caused by battery, starter, ignition, fuel, air, compression, ECM, wiring, sensor, or security-related faults. Diagnosis should begin by identifying whether the engine cranks normally. == Overview == A no-start condition should first be divided into two basic types: * '''No crank''' - the starter does n..."

2026-07-06T10:48:13Z

Created page with "'''No-start diagnosis''' is an overview of diagnostic steps for a Pontiac Fiero that cranks but does not start, or does not crank at all. No-start problems can be caused by battery, starter, ignition, fuel, air, compression, ECM, wiring, sensor, or security-related faults. Diagnosis should begin by identifying whether the engine cranks normally. == Overview == A no-start condition should first be divided into two basic types: * '''No crank''' - the starter does n..."

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'''No-start diagnosis''' is an overview of diagnostic steps for a [[Pontiac Fiero]] that cranks but does not start, or does not crank at all.

No-start problems can be caused by battery, starter, ignition, fuel, air, compression, ECM, wiring, sensor, or security-related faults. Diagnosis should begin by identifying whether the engine cranks normally.

== Overview ==

A no-start condition should first be divided into two basic types:

* '''No crank''' - the starter does not turn the engine.
* '''Crank, no start''' - the starter turns the engine, but the engine does not run.

These two conditions have different likely causes and should be diagnosed differently.

== No crank ==

A no-crank condition may be caused by battery problems, bad connections, starter failure, neutral safety switch or clutch switch problems, ignition switch problems, wiring faults, or ground problems.

Related topics:

* [[Battery]]
* [[Starter]]
* [[Starter problems]]
* [[Battery cables]]
* [[Ground problems]]
* [[Ignition switch]]
* [[Neutral safety switch]]
* [[Clutch safety switch]]

== Crank, no start ==

A crank/no-start condition usually requires checking for ignition spark, fuel pressure, injector operation, ECM power, sensor signals, and mechanical condition.

Basic checks include:

* Does the engine have spark?
* Does the fuel pump run briefly when the key is turned on?
* Is there correct fuel pressure?
* Are the injectors firing?
* Are any [[Diagnostic trouble codes]] stored?
* Does the engine have compression?
* Are the distributor, timing, and ignition components functioning correctly?

== Ignition checks ==

Ignition problems are a common cause of crank/no-start conditions.

Related topics:

* [[Ignition module failure]]
* [[Ignition coil]]
* [[Distributor]]
* [[Pickup coil]]
* [[Spark plug replacement]]
* [[Ignition timing]]
* [[Code 42]]

== Fuel checks ==

Fuel delivery problems can also cause crank/no-start conditions.

Related topics:

* [[Fuel pump problems]]
* [[Fuel pressure test]]
* [[Fuel pump relay]]
* [[Oil pressure switch]]
* [[Fuel filter replacement]]
* [[Fuel injectors]]
* [[Fuel pressure regulator]]

== ECM and electrical checks ==

The ECM and related wiring must receive proper power and ground for the engine to run.

Related topics:

* [[ECM]]
* [[ALDL diagnostics]]
* [[Diagnostic trouble codes]]
* [[Ground problems]]
* [[Fuses and relays]]
* [[Wiring diagrams]]
* [[Connector pinouts]]

== Mechanical checks ==

If spark and fuel are present, mechanical condition should be checked.

Related topics:

* [[Compression test]]
* [[Timing chain]]
* [[Valve timing]]
* [[Vacuum leaks]]
* [[Engine]]

== Diagnostic order ==

A practical diagnostic order is:

# Verify battery voltage and cable condition.
# Determine whether the engine cranks.
# Check for spark.
# Check fuel pump operation.
# Check fuel pressure.
# Check injector operation.
# Read diagnostic trouble codes.
# Inspect grounds, fuses, connectors, and wiring.
# Check compression and mechanical timing if needed.

== Notes ==

Avoid replacing parts at random. A no-start condition should be diagnosed by testing one system at a time.

On Fieros, ignition module failure, pickup coil failure, fuel pump problems, bad grounds, poor connections, and wiring issues are common causes of no-start complaints.

== See also ==

* [[Common problems]]
* [[Service procedures]]
* [[ALDL diagnostics]]
* [[Diagnostic trouble codes]]
* [[Ignition module failure]]
* [[Fuel pump problems]]
* [[Ground problems]]

[[Category:Fieropedia]]
[[Category:Diagnostics]]
[[Category:Common problems]]

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