What did you do to your NBS GMT800 Tahoe/Yukon Today?

[nonickatall]

Me too, bought my Summit used and brocken, disassembled it, repaired it, pimpt him with better wheels, installed a storring system, and some detail changes polished everything. Installed a stainless steel cover for the fat pan, so that the cleaning is easy.

I love this grill. Power, Possibilty, Space and i love this "old" American Design where you can feel that that was a good time in America, where America was great, proud, mostly united in the idea of "a free country and endless possibilities" and rich (ok, mostly... Compare to other countries).

And there was good quality.

The same as with our cars. These cars where build at the right moment in the history of the car industry. Where the cars had a good quality and where modern enough for good transmissions, sound systems, automatic air-conditioning on so on.

Today we are on both sides on the end. The modern technology is amazing, from the sixties view like in a science fiction.
But in the same time the quality is so bad. Cars have become disposable products..

There will be no legends any more like a gmt800. And there will be no good Webers anymore...

So our Webers, and our cars are: "Like a Rock (in history)"

Philosophical thoughts on cars and barbecue...

"Like an old white Man...",,

 

[Gmg0547]

Me too, bought my Summit used and brocken, disassembled it, repaired it, pimpt him with better wheels, installed a storring system, and some detail changes polished everything. Installed a stainless steel cover for the fat pan, so that the cleaning is easy.

I love this grill. Power, Possibilty, Space and i love this "old" American Design where you can feel that that was a good time in America, where America was great, proud, mostly united in the idea of "a free country and endless possibilities" and rich (ok, mostly... Compare to other countries).

And there was good quality.

The same as with our cars. These cars where build at the right moment in the history of the car industry. Where the cars had a good quality and where modern enough for good transmissions, sound systems, automatic air-conditioning on so on.

Today we are on both sides on the end. The modern technology is amazing, from the sixties view like in a science fiction.
But in the same time the quality is so bad. Cars have become disposable products..

There will be no legends any more like a gmt800. And there will be no good Webers anymore...

So our Webers, and our cars are: "Like a Rock (in history)"

Philosophical thoughts on cars and barbecue...

"Like an old white Man...",,

Best thing I've heard all day!

 

[nonickatall]

Das Beste, was ich den ganzen Tag gehört habe!

I hope you heard not only bulls. the whole day and this was slight above zero...?

 

[Gmg0547]

I hope you heard not only bulls. the whole day and this was slight above zero...?

Haha, not a bad day. Just a great write up that hit me in the right spot I guess. I'll admit I partly bought this vehicle about 6 months ago as a mini midlife crisis and it's kind of became a little addiction. It's cool to hear how many people still love these trucks and I still see them everywhere around here. My wife thinks I'm crazy, but I've developed a passion to learn about them and work on them as much as I can....when needed!

 

[MassHoe04]

Has been in low to mid-90's F the last two days...
I ran the gas down to about 5 gallons.
Opened the gas cap and PSSSSSSSSSSSSSSSSSSH!

Holy crap!! The rush of escaping air blasted me in the face like the Avatar ride at Disney!

The air rushing out kept going and going and going. Seemed like for ever after taking the gas cap off. I go to put gas in but the air still coming out pushed the first quart I pump in right back out.

Never saw that much pressure!

I got the tank full and left the cap off for the ride down to the BBQ place and back.
Tightened the cap for the night and checked in the morning when it was about 50 F. No pressure. Drove to work 26 miles this morning and checked again... No pressure (meaning no escaping air from the filler cap... not talking about fuel line pressure from the pump - truck running great).

That heat really did it yesterday.

This had me LOL, because my persistent CEL code is for the Evap. large leak and I am frequently getting "Tighten Gas Cap" messages on the DIC!

Does this help narrow down what the Evap. code really is trying to tell me?

Extreme pressure build up in the tank when ambient temp. is very hot, yet previous codes telling me there is large leak in vent system... Pointing to filler vent tube, evap. canister or vent valve module?

 

[ivin74]

Has been in low to mid-90's F the last two days...
I ran the gas down to about 5 gallons.
Opened the gas cap and PSSSSSSSSSSSSSSSSSSH!

Holy crap!! The rush of escaping air blasted me in the face like the Avatar ride at Disney!

The air rushing out kept going and going and going. Seemed like for ever after taking the gas cap off. I go to put gas in but the air still coming out pushed the first quart I pump in right back out.

Never saw that much pressure!

I got the tank full and left the cap off for the ride down to the BBQ place and back.
Tightened the cap for the night and checked in the morning when it was about 50 F. No pressure. Drove to work 26 miles this morning and checked again... No pressure (meaning no escaping air from the filler cap... not talking about fuel line pressure from the pump - truck running great).

That heat really did it yesterday.

This had me LOL, because my persistent CEL code is for the Evap. large leak and I am frequently getting "Tighten Gas Cap" messages on the DIC!

Does this help narrow down what the Evap. code really is trying to tell me?

Extreme pressure build up in the tank when ambient temp. is very hot, yet previous codes telling me there is large leak in vent system... Pointing to filler vent tube, evap. canister or vent valve module?

Your problem is the the evap system is not working and not venting the pressure off to the intake manifold or the carbon canister. The evap sensor/valve at the intake manifold and the evap sensor/valve at the carbon canister are both bad. The way the system works is if the vehicle is running the pressure is release to the intake and the canister valve stays shut, If the vehicle is off the valve at the intake is shut and the valve on the carbon canister is open letting the pressure release thru the canister.

You need to get it look at asap

 

[Fless]

Suspect an intermittent canister vent valve, or a circuit problem on that valve. Mine was intermittent when I changed it out.

The purge valve on the engine should be closed with the engine off so it will seal that end of the evap system. Normal. Most of the time it's closed until commanded to purge the canister fumes, done only when engine running. If it was incorrectly open (when engine off) it would be allowing fumes into the intake manifold, causing flooding and hard starts. And being open it would have the opposite effect, relieving evap system pressure. Nothing to see here.

You can test the canister vent valve by trying to blow through it and alternately applying 12v DC to the terminals. It should be open (able to blow through) with no voltage, and closed with 12v applied. Location shown below on '04 Flex Fuel system.

 

[MassHoe04]

Suspect an intermittent canister vent valve, or a circuit problem on that valve. Mine was intermittent when I changed it out.

The purge valve on the engine should be closed with the engine off so it will seal that end of the evap system. Normal. Most of the time it's closed until commanded to purge the canister fumes, done only when engine running. If it was incorrectly open (when engine off) it would be allowing fumes into the intake manifold, causing flooding and hard starts. And it would have the opposite effect, relieving evap system pressure. Nothing to see here.

You can test the canister vent valve by trying to blow through it and alternately applying 12v DC to the terminals. It should be open (able to blow through) with no voltage, and closed with 12v applied. Location shown below on '04 Flex Fuel system.

View attachment 396990

I have a Tech 2, so I can check the valve response to open/close commands.
I haven't had time to pull it out and test yet.

Purge valve is new. Never had problems filling the tank. Even after the pressure build-up last night, I was able to fill the tank OK.

At least I know the cap is not the issue! If it can hold back that amount of pressure, it sure isn't loose or not able to seal tightly...

 

[clandr1]

I have a Tech 2, so I can check the valve response to open/close commands.
I haven't had time to pull it out and test yet.

Purge valve is new. Never had problems filling the tank. Even after the pressure build-up last night, I was able to fill the tank OK.

At least I know the cap is not the issue! If it can hold back that amount of pressure, it sure isn't loose or not able to seal tightly...

I wonder if you have charcoal pellets clogging your EVAP lines, causing the pressure to build rather than vent to the purge solenoid/vent canister when it's activated?

 

[Fless]

It could also be a plugged canister, but that's a bit further down the testing line, I would think.

Do test with the Tech 2, but don't be fooled by the commanded state of the vent valve, it can work electrically but still not open/close properly. As I noted, mine was intermittent and testing on the bench confirmed that.