09 Tahoe, New fuel pump.. fuel rails dry

[Skeer]

Ok so new member here! And I've got a problem that I hope someone can help with. 2009 Tahoe, 5.3 FF with ~198k miles. Discovered a pin hole leak in the output nipple on the original fuel pump. So I ordered a Delphi replacement, got it installed today in fact, and my pressure gauge is 0. I even pulled the valve core out and nothing.. not even a gas smell.
So trying to take a logical approach, I dropped the tank again, pulled the pump out and set it up in a 5 gallon bucket. Clipped the cig lighter adapter off an old tire inflator to power it and once that entire white plastic "basket" is submerged it began pumping pretty good.
So.. pump is good. So I raise it back into place and hook everything back up except for the line that runs to the engine. Turn the key and I hear the pump prime....but nothing. I crank it a total of about 30 seconds and still nothing. I dropped the tank again, checked al the lines and nothing plugged up.

Ok.. think, what now? Ok there's not enough gas in the tank. So I dump my 5 gallon cans (in the end, all 4). Gauge reads *full*. Still, rails dry, no pressure no nothing.

WTF might be going on?

 

[Brandon2489]

May want to look into the fuel pump contro
l module. There is also a recall on them. May want to look into it.

 

[swathdiver]

Ok so new member here! And I've got a problem that I hope someone can help with. 2009 Tahoe, 5.3 FF with ~198k miles. Discovered a pin hole leak in the output nipple on the original fuel pump. So I ordered a Delphi replacement, got it installed today in fact, and my pressure gauge is 0. I even pulled the valve core out and nothing.. not even a gas smell.
So trying to take a logical approach, I dropped the tank again, pulled the pump out and set it up in a 5 gallon bucket. Clipped the cig lighter adapter off an old tire inflator to power it and once that entire white plastic "basket" is submerged it began pumping pretty good.
So.. pump is good. So I raise it back into place and hook everything back up except for the line that runs to the engine. Turn the key and I hear the pump prime....but nothing. I crank it a total of about 30 seconds and still nothing. I dropped the tank again, checked al the lines and nothing plugged up.

Ok.. think, what now? Ok there's not enough gas in the tank. So I dump my 5 gallon cans (in the end, all 4). Gauge reads *full*. Still, rails dry, no pressure no nothing.

WTF might be going on?

Tech-2 time.

 

[Skeer]

Thanks guys.. this is our primary vehicle, been paid off for a couple years now. And we live about 20 miles from the nearest dealer.. or person with a tech2 that I know of. Anyway so hypothetical situation here. Say a person was replacing a fuel pump right? And the main pump connector broke so they ordered a replacement from Delphi. The wire colors did not match so the person might have had the first few attempts at running it with groups to the sensor, hot to maybe another sensor… sensor ref wire to a hot, you get the idea. Could this person had of maybe burnt something in this control module by chance?

But, more importantly how would this module stop fuel from reaching the engine?

Lastly, there are no codes being thrown presently.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving sage troubleshooting questions and advice from the knowledgeable folks on this Forum.

Have you checked out the Tech 2 owner list of this Forum's members? It appears to me that you need some troubleshooting help that only a sophisticated bi-directional scanner/programmer can provide, particularly if your 'hypothetical' situation is not quite so hypothetical.. Otherwise, you're just walking blind in the dark.

 

[Skeer]

Thanks, Joseph, Yeah I did checkout the list and the closest person to is in Livonia which is about 3-ish hours south. So I'm still confused how that module might physically limit fuel from being pumped when the pump is running like normal. The KOEO prime period, and while cranking the pump is pumping. There's not some sort of valve or something between the tank and the engine that could be restricting flow right?

This morning I've been looking and only one Autozone near me has a driver module in stock, so I was going to run and get one just test swap but then I read how the things have to be programmed UGH.

I wonder.. could a regulator fail and block flow entirely?

 

[Skeer]

OK so I checked.. the regulator is integrated with the pump assembly. So that's not the issue. I slide back underneath and there is literally nothing between the tank output line and the driver side fuel rail except line. Nothing at all that could interrupt flow.

I unhooked the flex line where it connects to the driver-side rail and nothing comes out.

The only piece left is the fuel pump control/driver module..So I finally read how the programming is required based on VIN (although I'd love to try once from another 2009 5.3l flex)
So the dilemma now is: $194 on eBay for an FSCM programmed for your VIN.. or upwards of $5-700 for the towing and a dealer to do it. What do you folks think? The pump has been tested, the pump powers up and has a priming sound correctly.. AND the lines are clear, what else could it be?

 

[BG1988]

Ok so new member here! And I've got a problem that I hope someone can help with. 2009 Tahoe, 5.3 FF with ~198k miles. Discovered a pin hole leak in the output nipple on the original fuel pump. So I ordered a Delphi replacement, got it installed today in fact, and my pressure gauge is 0. I even pulled the valve core out and nothing.. not even a gas smell.
So trying to take a logical approach, I dropped the tank again, pulled the pump out and set it up in a 5 gallon bucket. Clipped the cig lighter adapter off an old tire inflator to power it and once that entire white plastic "basket" is submerged it began pumping pretty good.
So.. pump is good. So I raise it back into place and hook everything back up except for the line that runs to the engine. Turn the key and I hear the pump prime....but nothing. I crank it a total of about 30 seconds and still nothing. I dropped the tank again, checked al the lines and nothing plugged up.

Ok.. think, what now? Ok there's not enough gas in the tank. So I dump my 5 gallon cans (in the end, all 4). Gauge reads *full*. Still, rails dry, no pressure no nothing.

WTF might be going on?

could be vapor lock

 

[Bill 1960]

OK so I checked.. the regulator is integrated with the pump assembly. So that's not the issue. I slide back underneath and there is literally nothing between the tank output line and the driver side fuel rail except line. Nothing at all that could interrupt flow.

I unhooked the flex line where it connects to the driver-side rail and nothing comes out.

The only piece left is the fuel pump control/driver module..So I finally read how the programming is required based on VIN (although I'd love to try once from another 2009 5.3l flex)
So the dilemma now is: $194 on eBay for an FSCM programmed for your VIN.. or upwards of $5-700 for the towing and a dealer to do it. What do you folks think? The pump has been tested, the pump powers up and has a priming sound correctly.. AND the lines are clear, what else could it be?

There is a Dorman FSCM that is plug and play, ready to go. At least for my 2008. I’ll see if I can find my post with the part number…

”Dorman FPCM / FSCM part number 601-022”. Fits mine, you’ll want to confirm if the 2009 differs.

 

[Skeer]

nah I still don’t think it’s the fscm. So the purpose of the fscm, is to A fire the pump to prime in KOEO, and B to fire it when the engine is cranking. So since that happens voltage is being delivered when it’s required, correctly. What I am thinking now is that there is a split in the plastic line in the fuel pump assembly that’s squeezed open when the top portion is compressed down In the tank. I mean it worked when I tested it in the five gallon bucket. I will be dropping the tank again tomorrow and removing the pump to check this.