Your fuel system delivers gasoline (or diesel) from the tank to the engine under controlled pressure, at the precise rate the engine needs. The components — pump, lines, filter, rail, injectors — work together with the engine control module to atomize fuel for clean combustion. When any of them degrade, you lose fuel economy, performance drops, and the check-engine light eventually comes on. Frank's Automotive in New Braunfels diagnoses fuel-system issues with proper pressure testing and injector analysis, not just parts swaps.
What's involved
A fuel-system service or diagnosis covers:
- Fuel pressure test — static and running. Modern systems run 40 to 90+ PSI depending on engine design
- Fuel filter replacement — modern vehicles often have lifetime filters in the tank; older ones have inline filters around 30,000 miles
- Fuel pump diagnosis — current draw + pressure-and-volume test. A pump can pressure-test fine and still fail to deliver under load
- Injector flow testing — real injector service means bench-testing flow and spray pattern, or a professional-grade chemical service in the rail
- Direct-injection carbon cleaning — many modern direct-injected engines (VW/Audi, BMW, GDI Ford) build up carbon on intake valves; we do walnut-blasting where required
- Fuel-tank issues — pump-module gaskets, level-sender problems, evap-system codes pointing back to the tank
When to bring it in
Bring it in if you notice:
- Loss of fuel economy — your normal mpg drops 10-20% with no other change in driving
- Hesitation, stumbling, or surging under acceleration
- Rough idle, especially when cold
- Long crank before the engine starts (fuel pressure bleeding off when off)
- Check-engine light with codes pointing to fuel trim (P0171/P0174 system lean) or injector circuits (P0201–P0208)
- Fuel smell at the vehicle (fuel leak — pull over immediately)
- Reduced power combined with reduced fuel economy — often direct-injection carbon buildup on intake valves
A fuel-system problem rarely fixes itself. The longer you drive on weak fuel pressure or fouled injectors, the more strain you put on the catalytic converter and the closer you get to needing a $1,000+ component replacement.
Why Frank's for fuel system service
Our techs are ASE Certified and we're a Bosch Service Center — Bosch makes the fuel injectors, fuel pumps, and direct-injection components in a huge percentage of modern vehicles, and we have the diagnostic and service equipment to do the work properly. We carry OEM-equivalent fuel system components and the work is covered by our 24-month / 24,000-mile warranty.
If it's an emergency, the fastest path is the phone — call (830) 627-3939. For a non-emergency drivability concern, request an appointment and we'll get you on the diagnostic schedule.