This has started fine up till a day ago. Now, Nothing?

FOURBIT

MEMBER
1998 GMC SIERRA

This has started fine up till a day ago. Now, Nothing. The fuel pump has been heard well up till now. And, it appears that there is no fuel getting to the engine.

How do I troubleshoot this. I can't just replace the fuel pump and see if that works. GM wants around $500 for the complete module. :( After market wants around $200. YIIIKES!

So, where do I start?

Thanks in advance.

Paul

1 Reply

SQM

MECHANIC
6,383 POSTS

Hello,

When a fuel pump stops working the first item needs to be checked is the fuel pump relay.
The fuel pump relay is located in the fuse box under the hood (see diagram below).
That fuse block is located in the left rear side of the engine compartment, on the fender.
Visually check for any corrosion on the terminal or any burnt pin(s).
You can also test the relay.

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

https://www.2carpros.com/articles/how-to-check-wiring

Be sure to check to see if you are getting power to the relay as well.
If you are getting power to the relay and the relay is good. Then check to see if you are getting power to the pump. If you are getting power to the pump but the pump is not coming on, then it is likely a bad fuel pump.

https://www.2carpros.com/articles/how-a-fuel-pump-works
https://www.2carpros.com/articles/how-to-replace-an-electric-fuel-pump

I have attached the diagrams for your reference.

Please let me know of any questions.

Thank you.