Express Diesel Stalling Reduced Power

The symptoms you describe sound familiar. While not on a Chevy, I encountered comparable issues with a 2018 Audi A6. The engine stalling and power reduction, in particular, strongly suggest a problem within the high-pressure fuel system. Have you attempted any diagnostic procedures, such as reading the fault codes using an OBD II scanner? Knowing the specific code will help pinpoint the malfunctioning component. Furthermore, could you describe the conditions under which the stalling occurs? Is it more frequent when the engine is cold, warm, or irrespective of engine temperature? Obtaining the Freeze Frame data from the ECU (Engine Control Unit) at the time of the fault could be invaluable.

Thanks for the reply. I did pull the codes and it points towards the fuel volume regulator. The stalling seems to happen more when the engine is warm, like after driving for a while and then stopping at a light. What was the diagnosis for your Audi, and what did it take to fix it?

In my Audi's case, the fault codes also suggested a fuel pressure regulation issue. After conducting thorough tests, including pressure readings and component checks, the eventual diagnosis was a failing high-pressure fuel pump. Given the mileage on your Express and the warm-engine stalling symptom, it's highly probable the pump is indeed the culprit, leading to the fuel volume regulator errors. If the fault codes are definitively pointing to the regulator, and considering your symptoms, replacing the high-pressure fuel pump is the logical next step. However, given the complexity of the high-pressure fuel system, I'd strongly advise having a qualified technician perform the replacement. It's crucial to ensure proper installation and system calibration to prevent further issues. A garage will also be able to perform further diagnostics to fully exclude other failing parts.

Appreciate the insight. I'll take it to a reputable shop for a proper diagnosis and likely a high-pressure fuel pump replacement. They quoted me around 1510€ for the repair including parts and labor. Thanks again for confirming my suspicions.