If you're having fuel pump issues, the problem likely lies with:
* The PCM itself: A faulty PCM can prevent the fuel pump from activating.
* The fuel pump relay: This relay acts as an intermediary between the PCM and the fuel pump. A bad relay will prevent the pump from working. This is a more common and easier-to-replace component than the PCM.
* The fuel pump: The pump itself might be failing.
* Wiring: Damaged or corroded wiring between the PCM, relay, and fuel pump can also cause problems.
* Inertia switch: Some Blazers have an inertia switch that cuts power to the fuel pump in the event of a collision. This switch might have tripped. This is usually found under the dash or in the engine compartment.
To troubleshoot, you'll need to:
1. Check the fuel pump relay: Locate the relay (consult your owner's manual or a repair manual), and try swapping it with a known good relay of the same type.
2. Check the inertia switch: Locate this switch and make sure it hasn't been tripped. There's usually a reset button.
3. Check the fuses: Check relevant fuses related to the fuel pump and ignition system.
4. Have it professionally diagnosed: If the above steps don't solve the issue, a mechanic can use a scan tool to check for diagnostic trouble codes (DTCs) from the PCM that can pinpoint the problem.
In short, there's no simple fuel pump switch to flip. The system is electronically controlled. Focus your troubleshooting on the relay, inertia switch, fuses, and then consider more involved diagnostics.
