How to Troubleshoot the Fuel Systems of 1997 S-10 Chevy Blazers

by Lee Sallings
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The fuel system in your 1997 Chevy S-10 Blazer consists of an in-tank fuel pump, fuel injectors and an on-board computer. By isolating each component and testing separately from the other parts, the cause of failures can easily be found. Each component should be tested for electrical function, as well as mechanical function, before deciding if the part is faulty. Several relatively inexpensive pieces of test equipment are required, and they are all available at most auto parts stores.

Step 1

Locate the fuel pressure test port on the fuel rail that supplies fuel to the injectors. Remove the black plastic dust cap from the test port. Screw the fuel pressure tester onto the test port. Cycle the ignition key from the "Off" position to the "Run" position then back to the "Off" position three times.

Step 2

Turn the key to the "Run" position and observe the pressure indicated on the pressure tester. For a 1997 Chevy S-10 Blazer, the correct fuel pressure is between 55 and 62 PSI with the engine off and the key in the "Run" position. If it is low, replace the fuel pump. If it registers 0 PSI, proceed to the next step.

Step 3

Test for power at the fuel pump by probing the gray wire at the fuel pump electrical connector located on the frame just behind the fuel tank. With the power clips on the tester attached to the battery, push the probe end of the tester into the gray wire. Have an assistant turn the key to the "Start" position. There should be power indicated on the gray wire. If it is and the fuel pressure is 0, replace the fuel pump. If power is not indicated on the gray wire, proceed to the next step.

Step 4

Remove the fuel pump relay located in the under-hood fuse block near the battery. Turn the key to the "Run" position and touch the probe end of the circuit tester to each of the terminals. Two of the terminals will indicate power is present, and one will indicate ground is present. The fourth one should indicate ground is present when the key is turned to the "Start" position. If no ground is indicated when the key is in the "Start" position, replace the on-board computer. If ground is indicated, replace the relay.

Step 5

Unplug one of the electrical connectors from a fuel injector and insert a fuel injector test light (noid light) into the connector. Turn the key to the "Start" position and observe the light. It should flash when the engine is cranked. If the noid light doesn't flash, replace the ignition module. If the noid light flashes, proceed to the next step.

Step 6

Use a mechanic's stethoscope to listen for a clicking sound coming from the injectors when the engine is cranked. A clicking sound is normal and happens when the solenoid closes in the injector. Replace the injector if it doesn't click.

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