Chevrolet spark stalled and at times wont start or idle but cranks
Some potential solutions:
EGR (Exhaust Gas Recirculation): You mentioned that you cleaned the EGR, but it's still showing as a fault. The EGR system recirculates exhaust gases back into the intake manifold to reduce emissions. If the EGR valve is malfunctioning or clogged, it can affect engine performance.
Here are some steps to consider:
Check for Vacuum Leaks: Inspect the vacuum lines connected to the EGR valve for leaks or cracks. A vacuum leak can disrupt EGR operation.
Test the EGR Valve: Use a vacuum pump to check if the EGR valve opens and closes properly. If it doesn't, consider replacing it.
Clean the Intake Manifold: Sometimes carbon buildup in the intake manifold can affect EGR flow. Clean the intake manifold thoroughly.
Thermostat: You've already replaced the thermostat, which is good. A faulty thermostat can cause overheating or poor engine performance. Make sure the new thermostat is functioning correctly.
System Voltage Low: This could be related to the charging system (alternator, battery, or wiring).
Here are some steps to troubleshoot:
Check Battery Voltage: Measure the battery voltage when the engine is off and when it's running. It should be around 12.6V when off and around 13.8-14.4V when running.
Inspect Alternator: Ensure the alternator is charging properly. If it's not, consider replacing it.
Check Grounds and Wiring: Loose or corroded connections can cause voltage issues. Inspect battery terminals, ground connections, and wiring.
Idle Issues: If the engine won't idle properly, consider the following:
Idle Air Control Valve (IACV): The IACV controls idle speed. Clean or replace it if necessary.
Throttle Body Cleaning: A dirty throttle body can affect idle quality. Clean it using throttle body cleaner.
Vacuum Leaks: Check for vacuum leaks around the intake manifold, hoses, and gaskets.
Timing Chain: The B12D1 engine uses a timing chain. However, if it's stretched or worn, it can cause issues like poor performance or stalling. Consider having the timing chain inspected and replaced if needed.
Remember that diagnosing engine issues can be complex, and it's often best to consult a professional mechanic or use diagnostic tools.
