* Fuel Delivery Problems:
* Clogged fuel filter: A dirty fuel filter restricts fuel flow to the engine.
* Weak fuel pump: The fuel pump may not be delivering enough pressure or volume. This is more likely if the problem worsens when the engine is under load (like using the AC or driving uphill).
* Fuel pressure regulator: A faulty regulator might not maintain the correct fuel pressure.
* Clogged fuel injectors: Blocked injectors prevent proper fuel atomization and combustion.
* Bad fuel: Contaminated fuel can cause similar issues.
* Ignition System Problems:
* Weak spark: A failing ignition coil, spark plug wires, or spark plugs themselves can result in a weak or intermittent spark, leading to the engine dying under load.
* Crankshaft Position Sensor (CKP) or Cam Position Sensor (CMP): These sensors tell the computer the engine's position, and a faulty sensor can cause misfiring and stalling.
* Air Intake System Issues:
* Mass Airflow Sensor (MAF) problem: A dirty or faulty MAF sensor provides inaccurate readings to the engine computer, leading to improper fuel delivery.
* Vacuum leaks: Leaks in the intake system can disrupt the air-fuel mixture.
* Electrical Issues:
* Alternator: A failing alternator may not be charging the battery properly. The engine might start, but once the battery's charge is depleted, the engine dies.
* Battery: A weak or dying battery can prevent the engine from continuing to run, especially under load.
* Engine Mechanical Problems:
* Low compression: Worn piston rings or valve problems can lead to insufficient compression, causing the engine to stall. This is less likely to cause starting issues, but the engine might die as soon as load is applied.
Troubleshooting Steps:
1. Check the battery: Make sure the battery terminals are clean and tight, and test the battery voltage.
2. Listen for unusual noises: Is there any unusual clicking, whirring, or grinding when trying to start?
3. Check engine codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the engine computer. These codes can provide valuable clues.
4. Inspect the fuel filter: Check the fuel filter for signs of clogging.
5. Check the air filter: A clogged air filter can restrict airflow and cause similar problems.
If you're not comfortable diagnosing and repairing these issues yourself, it's best to take your Chevy truck to a qualified mechanic for proper diagnosis and repair. Attempting some repairs without proper knowledge can potentially cause further damage.
