GDI

📖 YOUCANIC Automotive Glossary

GDI (Gasoline Direct Injection) injects fuel directly into the combustion chamber at 500-3,000+ PSI rather than into the intake port. Direct injection allows more precise fuel metering, better atomization, higher compression ratios, and 10-15% better fuel economy. GDI requires a camshaft-driven high-pressure fuel pump (HPFP) in addition to the standard in-tank pump.

The primary drawback is carbon buildup on intake valves — since fuel no longer washes over them, PCV oil vapors bake into hard deposits causing rough idle, misfires, and power loss. Some manufacturers use dual injection (GDI plus port injection) to solve this. DIYers with GDI engines should consider walnut shell blasting or chemical intake cleaning every 60,000-80,000 miles. Common DTCs: P0087 (Fuel Rail Pressure Too Low from HPFP issues).