Fuel system disengages after driving for few minutes

Tiny
CODY WOOD
  • MEMBER
  • 2001 CHEVROLET MALIBU
  • 3.1L
  • V6
  • 2WD
  • AUTOMATIC
  • 187,636 MILES
Fuel system stops working after driving. I have put two fuel pumps on it and a coil pack and the problem is still there. What could it be?
Friday, July 27th, 2018 AT 9:04 PM

1 Reply

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 108,179 POSTS
Hi Cody and thanks for using 2CarPros.com.

Based on your description, the first suspect I have is the fuel pump relay. The relay may be failing and stopping power to the pump.

Here is a link which shows how to check a relay:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

As far as the fuel pump relay, when the ignition switch is turned on, the power-train control module (PCM) energizes the fuel pump relay which applies power to the fuel pump. The fuel pump relay will remain on as long as the engine is running or cranking and the PCM is receiving reference pulses. If no reference pulses are present, the PCM de-energizes the fuel pump relay within two seconds after the ignition is turned on or the engine is stopped. The reference pulses come from the crankshaft position sensor. If that is going bad, it can indirectly cause the pump to be shut down.

I noticed you replaced the coils. Was that due to the loss of spark? If so, then the crankshaft position sensor could be an issue. Take a look at this link. It discusses the symptoms of a bad sensor.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

As far as the fuel pump relay, it is located under the hood in the relay box. I have attached a picture of the relay box to help you locate it. Under the lid, it will identify what each relay is for.

Let me know if you have other questions.

I hope this is helpful,
Joe

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Friday, July 27th, 2018 AT 10:05 PM

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