Crank but no start, dual tanks?

HUNTER4271

MEMBER
2009 CHEVROLET SILVERADO
6.0L
V8
4WD
AUTOMATIC
205,000 MILES

My truck has had a problem with not starting but turning over strong. I don’t believe it to be the fuel pump because it has never stopped. It is getting spark. And it seems to happen at random times. It does have two gas tanks on it if that makes a difference.

3 Replies

KEN L

MASTER CERTIFIED MECHANIC
47,574 POSTS

Hello,

First, we should check the fuses, and then can you turn the truck on without cranking the engine over? Can you hear the fuel pump run inside the tank for about 5 seconds? If not, can you try switching tanks? I have seen one with two tanks. Is it aftermarket?

This guide can help as well to see if there are any codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

This can help check the fuses with the locations in the diagrams below:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Also, here is a guide to help you go over things, Also I would disconnect the MAF sensor and if it starts the sensor is bad.

https://www.2carpros.com/articles/car-not-running-advanced

Check out the images (below). Please let us know what happens.

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Thursday, February 16th, 2023 AT 4:15 PM

HUNTER4271

MEMBER
2 POSTS

I don’t believe it to be the fuses or relays, we dug through them pretty extensively and tested everything. It’s dual tanked from the factory (cab and chassis). I don’t think it’s getting fuel. But I’m not sure the fuel pump is out. It runs great and does not feel like it’s choking for fuel when it is running. Any and all advice or pointers is greatly appreciated.

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Thursday, February 16th, 2023 AT 5:41 PM

KEN L

MASTER CERTIFIED MECHANIC
47,574 POSTS

I would try starting fluid in the intake tube to see if it runs to help narrow down the system what is not working. It does sound like the fuel pump is out and if so, here is how to replace it. It looks like both pumps run all the time; do you gas in both tanks? I found the wiring diagrams for the cab and chassis. So, I believe if one of the pumps stops the engine will stop running due to lack of fuel pressure. There is a fuse with two relays as well that run the pumps so we can start by checking those. Please check the fuel pump fuse #20 in the under-hood fuse panel. Here is a guide and you can swap out the fuel pump control relays one at a time as well:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

The primary relay is in the main fuse panel under the hood as well while the auxiliary pump relay is on the left side of the engine compartment. Check the wiring diagrams below to see how the system works. Please get back to me.

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