Fuel System
- Install Fuel Pressure Gauge (SA9127E). Turn ignition on. Fuel pressure reading should be 38-44 psi (2.7-3.1 kg/cm2
). If fuel pressure is as specified, see the TESTS W/O CODES
article. If fuel pressure is not specified, go to next step.
- Turn ignition off. Using a test light connected to ground, probe fuel pump fuse in fuse block. See Fig 1
. Turn ignition on. Test light should illuminate for 2 seconds, then turn off. If test light illuminates, check for open in fuel pump circuit (Gray wire) or ground circuit (Black wire). If circuits are okay, check fuel pump. If test light does not illuminate, go to next step.
- Turn ignition off. Repeat test with test light connected to fuel pump fuse. If test light does not illuminates, check for open or short to ground in Dark Green/White wire between fuel pump relay and PCM. See Fig 1
. If circuit is okay, check PCM connector tightness or for faulty PCM. If test light illuminates, go to next step.
- Remove fuel pump relay. Using a test light connected to ground, probe Red wire terminal between fuel pump relay and fuse block. See Fig 1
. If test light illuminates, check fuel pump relay connector tightness, for faulty fuel pump relay ground or for faulty fuel pump relay. If test light does not illuminate, check for faulty I/P BATT fuse. If fuse is okay, check and repair open in Red wire between fuel pump relay and fuse block.
Courtesy of GENERAL MOTORS CORP.