Residual Fuel Pressure

Perform fuel pressure regulator test. See FUEL PRESSURE REGULATOR  . To test residual fuel pressure, proceed as follows.

1. Stop engine, wait 10 minutes.
2. Check residual pressure. See FUEL PRESSURE SPECIFICATIONS  table. When the engine is hot, fuel pressure is higher. This is a normal condition caused by fuel expansion.
3. If residual pressure specification is NOT obtained: Check pressure tester connection (for leaks), check fuel lines (for leaks), check fuel pump check valve. See FUEL PUMP CHECK VALVE  . Also check fuel injectors for leaks. See FUEL SYSTEMS in SYSTEM & COMPONENT TESTING article.
4. If NO leaks are found (and fuel pump check valve is OK), replace fuel pressure regulator.
5. Repeat residual pressure test. After checking fuel pressures (system and residual pressures), check and erase the Diagnostic Trouble Code (DTC) memory. See SELF-DIAGNOSTICS article.