Diagnostic Aids
WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 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 failure.
If you have to prime the fuel system, check for the following conditions:
- A restricted fuel supply line.
- A fuel supply line air leak.
A sticking Fuel Pressure Regulator may set this DTC.
If the problem is still intermittent, see INTERMITTENT CONDITIONS under SELF-DIAGNOSTIC SYSTEM.