* Fuel Pump: A failing fuel pump, especially one weakened by age and heat, might not be able to maintain sufficient pressure at higher speeds or under load. The heat soak after you pull over allows it to cool down enough to work temporarily.
* Fuel Filter: A clogged fuel filter restricts fuel flow. This is exacerbated under high demand (freeway driving) and leads to similar symptoms.
* Fuel Pump Relay: The relay could be failing intermittently, cutting power to the fuel pump. Heat can make these problems worse.
* Mass Airflow Sensor (MAF) Sensor: A dirty or failing MAF sensor provides inaccurate readings to the engine computer, leading to a lean fuel mixture and stalling. This wouldn't necessarily explain the delayed restart, but is still a possibility to check.
* Crankshaft Position Sensor (CKP Sensor): A failing CKP sensor prevents the engine from knowing where the pistons are, interrupting the spark and fuel injection. Heat can also affect this sensor.
* Throttle Position Sensor (TPS): Similar to the MAF sensor, a faulty TPS can cause the engine to receive incorrect information about throttle position, leading to stalling.
Why it restarts after 10 minutes: The cooling-off period allows components that are heat-sensitive to recover enough to function temporarily.
What to do:
1. Check the check engine light codes: This is crucial. Get the diagnostic trouble codes (DTCs) read using a code reader (available at auto parts stores). The codes will point you toward the specific failing component.
2. Inspect the fuel filter: It's a relatively cheap and easy part to replace. A visibly clogged filter is a strong indication of the problem.
3. Consider the fuel pump: This is more involved but is a highly likely culprit given the symptoms. A mechanic might be needed for this.
4. Professional diagnosis: If you're not comfortable diagnosing and replacing parts yourself, take your Blazer to a qualified mechanic. They can properly diagnose the problem based on the codes and other tests.
Ignoring this issue could lead to complete engine failure, so addressing it promptly is vital. The fact that it restarts after a cooling period strongly suggests a heat-related issue within the fuel system.
