Chart A8 - Fuel Injection
- Pressure less than 30 psi can be of 2 types:
- Regulated pressure less than 30 psi is when the amount of fuel to injector is okay, but pressure is too low. System may run lean and set Code 44. In addition, engine may be hard starting and have poor overall performance.
- Restricted flow can cause pressure drop. Normally, a vehicle with a system pressure of less than 9 psi will not be driveable. If the pressure drop occurs only while driving, the engine will begin to surge then stop as pressure drops rapidly.
- Restricting fuel return line allows pump to develop maximum pressure. Pressure should exceed 60 psi.
- This test determines if high pressure is due to a restricted fuel return line or a pressure regulator problem.