What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[992dr]

Remember that’s just the tip of the iceberg. It’s way worse on the backside, where it started.

Ah yes, Unfortunately, I am aware of that. Sucks to have to deal with it on such a new vehicle.

 

[iamdub]

View attachment 352332

Amazon.com

After the car cools off some, we pull the engine cover and the cover for the fuel rail and attach this brass adapter a turn or two. Then we press onto the barb some 1/4" clear plastic tubing we have at the house (barb is 5/16"), about 5 or 6 feet long and then screw down the fitting which then depresses the schrader valve and fills the tubing with fuel. Then I begin to pour the fuel into the beaker until it hits the full line. Hopefully not too much and hopefully I remembered to put water in their first!

If the car has recently been driven, there's usually enough fuel in the rail to get a full sample without turning the key on to refill the rail.

I'm all set to do this too but it is pouring down rain these last few days.

This adapter is why I tagged you! I haven't bothered to test mine in so long since I know my PCM isn't reading the content correctly. But, I'll get this little gizmo when I do venture further in this.

 

[iamdub]

Doing an oil/filter change and going to replace some split loom that crumbled off a few months ago when replacing the oil pressure sender.

How does this clip in-clip? View attachment 352409

The stem slips over that threaded stud, the loop holding the wire is like a zip-tie. You can use a tiny (maybe sharpened?) screwdriver to pry the barb down to open up the loop. Otherwise, cut it off and replace it.

 

[iamdub]

Also pulled a fuel sample from the fuel rail. The test vial says just under 70% ethanol and my virtual sensor calculated 65%

View attachment 352413
View attachment 352415

Nice! I wish I knew why mine was stuck in the low-20s percentile, even with 65%+ actual alcohol content.

 

[RooTBeeRthe1st]

Doing an oil/filter change and going to replace some split loom that crumbled off a few months ago when replacing the oil pressure sender.

How does this clip in-clip? View attachment 352409

I need to do the same after changing my manifold.





Ordered parts for my own flex fuel sensor setup.
Ordered a few catch cans. See which one fits/I like better.
Only thing left I need to get is some AN lines.

 

[gooffeyguy]

View attachment 352332

Amazon.com

After the car cools off some, we pull the engine cover and the cover for the fuel rail and attach this brass adapter a turn or two. Then we press onto the barb some 1/4" clear plastic tubing we have at the house (barb is 5/16"), about 5 or 6 feet long and then screw down the fitting which then depresses the schrader valve and fills the tubing with fuel. Then I begin to pour the fuel into the beaker until it hits the full line. Hopefully not too much and hopefully I remembered to put water in their first!

If the car has recently been driven, there's usually enough fuel in the rail to get a full sample without turning the key on to refill the rail.

I'm all set to do this too but it is pouring down rain these last few days.

This adapter would rock if it had a pin so you wouldn't have to pull the core.

I ended up removing core, pushing on about a foot long piece of 3/8" fuel line running to a small cup and went and turned key on for a fraction of a second.

 

[RooTBeeRthe1st]

This adapter would rock if it had a pin so you wouldn't have to pull the core.

I ended up removing core, pushing on about a foot long piece of 3/8" fuel line running to a small cup and went and turned key on for a fraction of a second.

Do you pull the fuel pump relay and crank to drain the pressure before pulling the valve core?

 

[iamdub]

This adapter would rock if it had a pin so you wouldn't have to pull the core.

I ended up removing core, pushing on about a foot long piece of 3/8" fuel line running to a small cup and went and turned key on for a fraction of a second.

You don't have to remove the core. James was saying he screws the fitting on, pretty much just to hold it in place and likely to reduce the number of turns needed to tighten it with a hose on it (to reduce twists). He installs the hose then turns the fitting with the hose on it which gradually depresses the valve, letting the pressurized fuel bleed into the hose. He uses a clear hose so he can see it fill with fuel and knows when to stop and back the fitting off, closing the valve and stopping the fuel from filling the hose any further. I imagine he's holding the open end of the hose up so that the hose is U-shaped. Then, he slowly lowers the hose with the end draining into the vial, controlling it to get just the amount he needs.

 

[gooffeyguy]

You don't have to remove the core. James was saying he screws the fitting on, pretty much just to hold it in place and likely to reduce the number of turns needed to tighten it with a hose on it (to reduce twists). He installs the hose then turns the fitting with the hose on it which gradually depresses the valve, letting the pressurized fuel bleed into the hose. He uses a clear hose so he can see it fill with fuel and knows when to stop and back the fitting off, closing the valve and stopping the fuel from filling the hose any further. I imagine he's holding the open end of the hose up so that the hose is U-shaped. Then, he slowly lowers the hose with the end draining into the vial, controlling it to get just the amount he needs.

I got confused by his post. I read the first part and thought this adapter was just a hose barb fitting and he still removed the core, but I see now that it is an adapter to add a fuel pressure gauge and does depress the Schrader valve.

 

[gooffeyguy]

Do you pull the fuel pump relay and crank to drain the pressure before pulling the valve core?

I didn't. I relieved the pressure by pressing in on the valve with a small screw driver and also had a paper towel wrapped around the area. It only puked a little bit of fuel, which was absorbed by the paper towel.

 

[swathdiver]

This adapter would rock if it had a pin so you wouldn't have to pull the core.

I ended up removing core, pushing on about a foot long piece of 3/8" fuel line running to a small cup and went and turned key on for a fraction of a second.

You don't have to remove the core.

As you screw it down it depresses the core. Just used it again tonight and had to re-energize the fuel rail once to get a few more drops to fill the beaker.

Torque App showed Alcohol Content as being 66.7% and the beaker sample taken from the rail was right at 80%. Time to break out the Tech-2 when I get gas tomorrow and reset the alcohol content.

 

[RooTBeeRthe1st]

Already received some of the parts to start getting rid of the virtual garbage sensor.

 

[Fless]

As you screw it down it depresses the core. Just used it again tonight and had to re-energize the fuel rail once to get a few more drops to fill the beaker.

Torque App showed Alcohol Content as being 66.7% and the beaker sample taken from the rail was right at 80%. Time to break out the Tech-2 when I get gas tomorrow and reset the alcohol content.View attachment 352445

Are you going to reset the alcohol content while you have that much ethanol in it? Filling up with E85?

 

[swathdiver]

Are you going to reset the alcohol content while you have that much ethanol in it? Filling up with E85?

No, we'll probably use the Tech-2 and pump all the remaining fuel in the tank into a jerry can and then put 5 gallons of 93 in it from another jerry can, top it off at the gas station and then reset it after it finishes calculating for the new fuel. I considered driving around but don't really want to risk running out of gas or leaving too much E85 aboard when I hit the gas station.

The idiot light comes on nowadays when I have about 5.5-6 gallons still on board. After it came on last night, I drove it 26 miles so that should cut that number in half. Hmm, let me do some math... Yeah, if I drove straight to the station the AC might still be about 8%. Enough to do the reset but think I can get it closer. Maybe I should just take the long way to the station and throw a jerry can in back just in case. Boy, I sure do over-think things these days!

 

[iamdub]

As you screw it down it depresses the core. Just used it again tonight and had to re-energize the fuel rail once to get a few more drops to fill the beaker.

Torque App showed Alcohol Content as being 66.7% and the beaker sample taken from the rail was right at 80%. Time to break out the Tech-2 when I get gas tomorrow and reset the alcohol content.View attachment 352445

Nice- you have the widemouth vial. Mine's the smaller black plastic cap version. Where did you score E80?

 

[iamdub]

Already received some of the parts to start getting rid of the virtual garbage sensor.

Part number or link?
Better yet, a write up?

 

[George B]

Part number or link?
Better yet, a write up?

I found this.

2013 Chevy Silverado 5.3 FlexFuel Modification - PerformanceTrucks.net Forums

FUEL SYSTEMS - 2013 Chevy Silverado 5.3 FlexFuel Modification - I have a 2013 SIlverado with factory flex fuel. It has 40000 miles on it. I have modded the suspension (coilovers, caltracs, etc) and misc other aspects of the truck. Along the way attempting to prep it, as I intend to supercharge...

www.performancetrucks.net

 

[iamdub]

I found this.

2013 Chevy Silverado 5.3 FlexFuel Modification - PerformanceTrucks.net Forums

FUEL SYSTEMS - 2013 Chevy Silverado 5.3 FlexFuel Modification - I have a 2013 SIlverado with factory flex fuel. It has 40000 miles on it. I have modded the suspension (coilovers, caltracs, etc) and misc other aspects of the truck. Along the way attempting to prep it, as I intend to supercharge...

www.performancetrucks.net

Bookmarked. Thanks!

 

[RooTBeeRthe1st]

Part number or link?
Better yet, a write up?

I could do it right up I suppose once I get everything and actually get it done.

But honestly, from what I've seen. If you're okay with spending the money, just get the kit from DSX tuning, and all you have to do is take the signal wire from the sensor and find the right pin out on the ECM connector to put it in. Go into the tune and change it from virtual sensor to physical sensor and your supposedly done.

If you're set up is good on the stock fuel pump and fuel lines, then that's the best way to go. I bought that flex fuel bypass block thing with an fittings just in case I can't make the power I want on stock stuff... Which is pretty likely considering I like corn so much.
So that'll probably end up going on down the road when I have the Whipple kit on there.

 

[RooTBeeRthe1st]

I found this.

2013 Chevy Silverado 5.3 FlexFuel Modification - PerformanceTrucks.net Forums

FUEL SYSTEMS - 2013 Chevy Silverado 5.3 FlexFuel Modification - I have a 2013 SIlverado with factory flex fuel. It has 40000 miles on it. I have modded the suspension (coilovers, caltracs, etc) and misc other aspects of the truck. Along the way attempting to prep it, as I intend to supercharge...

www.performancetrucks.net

I hadn't seen that particular post, but that's pretty much what I was planning to do.