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stin1974, Transmission Tech
Category: Chevy
Satisfied Customers: 765
Experience:  Chevy Transmission Tech
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1997 chevy s10 blazer: quit running..getting fuel..fuel pump relay

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i have a 1997 chevy s10 blazer just quit running while driving i changed fule pump because it was not getting fuel but still no fuel and there is no power to fuel pump i also changed fuel pump relay please help
Have you checked the fuses themselves in the fuse panel inside the vehicle?
Customer: replied 7 years ago.
yes all are fine it is a 4.3
You will have to trace this back. I would start at the relay. See if you are getting power to the relay. If not you will have to trace the wires back to see where you lose power or if you do have power to it you will have to trace the wires forward. Basically you will need to do some wire tracing and trouble shooting to see where you are losing power and at what point. If the relay and fuses are all good that is what will be required. That is what I or any other mechanic would have to do.
Customer: replied 7 years ago.

i am not getting any power to relay where do i go to for power at relay

is it from the ignition or fuse

It goes from the ignition then to the fuse. If you have power at the fuse (to the fuse) then you will have to trace it from the fuse panel to the relay. Look to be sure that there are not any grouind wires off or lose. Its basically just going to take some time to visually inspect as well as with your meter to find where the problem is.
Customer: replied 7 years ago.
sorry it took so long to get back i have power from one wire to the relay and one that is ground that leaves me three more wires that are not ground or power should any of these three have power to them

Here is a diagram This should help you find where the problem is.


Customer: replied 7 years ago.

alright the diagram is helping using a jumper wire from the orange wire to the grey wire i get the fuel pump to come on and when i start the vehicle it dies after about 5 seonds but using that jumper wire it will start just wont stay running


So you are bypassing the fuel pump switch when you are doing this right?
Customer: replied 7 years ago.
i believe i am i really dont know i am using the jumper wire right at the relay plug in without the relay looking at your wiring diagram i guess i am

Ok im gonna give you the complete test procedure. 1 sec




Circuit Description
When the ignition switch is turned ON, the VCM turns ON the in-tank fuel pump. The in-tank fuel pump remains ON as long as the engine is cranking or running and the VCM is receiving the distributor reference pulses. If there are no reference pulses, the VCM shuts off the fuel pump within 2 seconds after the ignition ON or the engine stops.

Should the fuel pump relay or the 12 volt relay drive from the VCM fail, the fuel pump receives a supply current through the oil pressure switch backup circuit. The fuel pump test terminal is located in the driver's side of the engine compartment. When the engine is stopped, applying the battery voltage to the test terminal can turn on the fuel pump.

Diagnostic Aids
An inoperative fuel pump relay can result in long cranking times. The time necessary for the oil pressure to reach the pressure required in order to close the oil pressure switch and supply the necessary current for the fuel pump causes the extended crank period. If the fuel pump relay circuit checks out OK, refer to Fuel System Pressure Test . See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Component Tests and General Diagnostics\Fuel System Pressure Test

Excessive fuel may also cause long cranking times which is accompanied by the following conditions:

  • A start that is not as fast as normal.
  • A puff of black smoke at the tailpipe. An improperly connected or faulty EVAP canister control valve can cause this problem. Disconnect the EVAP purge hose from the EVAP canister control valve in order to diagnose. Refer to EVAP Canister Hoses .

One or more leaking poppet nozzles may also extend the cranking time. Perform the Poppet Nozzle Test, in the Injector Balance Test Table. Refer to Fuel Injector Balance Test . See: Powertrain Management\Computers and Control Systems\Testing and Inspection\Component Tests and General Diagnostics\Fuel Injector Balance Test Procedure

Test Description
The numbers below refer to the step numbers on the diagnostic table.

  1. This step checks for the correct operation of the fuel pump.
  2. This step checks the operation of the fuel pump by supplying 12 volts to the fuel pump control circuit.
  1. This step checks the battery feed circuit to the fuel pump relay.
  1. This step checks for the proper operation of the fuel pump relay.

This along with the diagram I gave you is everything.

Customer: replied 7 years ago.
if it is the switch where about is that located
This should get you there. Can you follow this?
Customer: replied 7 years ago.
i am gonna try
This should lead you to the problem.
Customer: replied 7 years ago.
everything is saying the fuel pump\ oilpressure switch can tou tell me where to begin to find it so i can go get another one to replace it


stin1974 and 6 other Chevy Specialists are ready to help you
Customer: replied 7 years ago.
sorry it took so long but i drive truck and i wanted to make sure i was all done and running before i accepted thank you very much and again sorry it took so long