Diagnostic Aids
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
- This DTC does not set for an idle condition.
- A number of conditions may cause DTC P0087 and DTC P1093 to set:
- Excessive fuel return to the tank
- A fuel injection pump failure
- A fuel pressure regulator (RPCV) failure
- If you have to prime the fuel system, inspect for the following conditions:
- A restricted fuel supply line
- A fuel supply line air leak-Refer to Fuel System Diagnosis .
- A sticking fuel pressure regulator may set this DTC. Refer to Fuel System Diagnosis - High Pressure Side . Perform this test under the conditions for which the DTC set.
- If power enhancing devices have been attached to the fuel rail pressure sensor circuits, this DTC may set and adversely effect the fuel system components. Refer to Fuel System Diagnosis - High Pressure Side .
- If the condition is still intermittent, refer to Intermittent Conditions .