Fuel System Service & Repair in Gastonia, NC

Modern European engines use Gasoline Direct Injection (GDI) — a technology that delivers fuel directly into the combustion chamber at extremely high pressure for maximum efficiency and power. While GDI engines perform exceptionally well, they have a known maintenance challenge: without fuel washing over the intake valves (as in port-injected engines), carbon deposits build up on the valve stems and backsides over time, restricting airflow and causing rough idle, misfires, reduced power, and poor fuel economy. Many BMW, Mercedes-Benz, Audi, Porsche, and Volkswagen engines use GDI and are susceptible to this buildup. At Import Auto Tech, we perform walnut shell blasting — the only effective method for removing GDI carbon deposits — without disassembling the engine.

Beyond carbon cleaning, our fuel system services address the complete fuel delivery circuit: high-pressure fuel pump (HPFP) replacement for direct-injection engines, low-pressure fuel pump replacement, fuel injector cleaning and testing, fuel filter service, fuel pressure regulator replacement, and fuel line inspection. We diagnose fuel system issues using factory scan tools that read live fuel pressure, injector pulse width, and high-pressure fuel system data — allowing us to pinpoint failing components precisely before recommending any parts replacement.

Fuel system symptoms vary widely: extended cranking before starting (often a failing HPFP or low-pressure pump), rough idle or misfires under load (injector issues or carbon buildup), fuel smell from the engine bay (fuel line or injector seal leak), power loss at high RPM (fuel pressure dropping under demand), or poor fuel economy without other apparent cause. If you're experiencing any of these symptoms in your BMW, Mercedes, Audi, or Porsche, our diagnostic process will identify the root cause accurately.