Wrangler TJ Gas Overflow Fix

[mrblaine]

On page 11 of this thread, Blaine fixes other people's Jeeps with the real fix. But if they happen to have tried to GM hose fix, he keeps that hose and breaks the flapper valve.

Easiest way I've ever found to remove it.
Lay it on the concrete, smash it with a hammer, dump out the pieces.

 

[freedom_in_4low]

Easiest way I've ever found to remove it.
Lay it on the concrete, smash it with a hammer, dump out the pieces.
View attachment 541666

elegant in it's simplicity. I love an excuse to take the 3 pounder off it's hanger.

 

[MikeE024]

I'm nearly certain Blaine doesn't use the GM filler hose, especially after the sanding method on the factory check valve was discovered a few years ago.

I installed it long before I took my rig to him. The notes said he removed the flapper valve so I assumed that’s what he did.

 

[freedom_in_4low]

Now that I've had it apart and fully understand how it works, I'm even more appalled that this never got a safety recall. With the plunger stuck in the lower position, the rollover valve is rendered inoperable and in the event of a rollover will dump fuel out the filler nipple like it's not even there. That's a clear safety issue if I've ever heard one.

Seems like they ran the numbers and decided the recall would be more expensive than a few wrongful death suits. Typical of domestic manufacturers, unfortunately.

 

[mrblaine]

Now that I've had it apart and fully understand how it works, I'm even more appalled that this never got a safety recall. With the plunger stuck in the lower position, the rollover valve is rendered inoperable and in the event of a rollover will dump fuel out the filler nipple like it's not even there. That's a clear safety issue if I've ever heard one.

Seems like they ran the numbers and decided the recall would be more expensive than a few wrongful death suits. Typical of domestic manufacturers, unfortunately.

Except that it won't dump fuel generally. These systems run a sealed gas cap that is pretty robust.

 

[freedom_in_4low]

Except that it won't dump fuel generally. These systems run a sealed gas cap that is pretty robust.

True, most of the time. It stands to reason that the filler hose being damaged or disconnected during the incident, or someone being unlucky enough to be in a rollover right after they drove away from the gas pump with the cap left on their bumper was considered a big enough risk to justify including the rollover valve when it was just an added feature on an existing tank. It would only have been when the cost came to repairing 180k tanks in a costly recall campaign that they decided to "send it".

Also possible that there just weren't enough warranty claims on it to catch their attention or the information about what was actually going on didn't make it to the right people. But there could definitely be a non-zero quantity above nominal of post-rollover gasoline fires without WTJF ever knowing about it. Probably wouldn't have helped matters that the issue was coming to light around the time of the financial crisis and automakers were laying off by the thousands and asking for bailouts.

My second hand experience in this area is a close relative (immediate family) that got a 7 figure settlement from GM compensating for life-altering injuries due to a known safety issue that occurs just rarely enough that they're willing to pay a handful of those settlements rather than recall and fix what's out there on the road. When it comes to these mega corporations it really is about the bottom dollar and nothing more. We shouldn't have any illusions that they care one bit for the consumer the way a small business like yours does. We're not even the customer. Only the shareholder matters.

 

[mrblaine]

True, most of the time. It stands to reason that the filler hose being damaged or disconnected during the incident, or someone being unlucky enough to be in a rollover right after they drove away from the gas pump with the cap left on their bumper was considered a big enough risk to justify including the rollover valve when it was just an added feature on an existing tank. It would only have been when the cost came to repairing 180k tanks in a costly recall campaign that they decided to "send it".

Also possible that there just weren't enough warranty claims on it to catch their attention or the information about what was actually going on didn't make it to the right people. But there could definitely be a non-zero quantity above nominal of post-rollover gasoline fires without WTJF ever knowing about it. Probably wouldn't have helped matters that the issue was coming to light around the time of the financial crisis and automakers were laying off by the thousands and asking for bailouts.

My second hand experience in this area is a close relative (immediate family) that got a 7 figure settlement from GM compensating for life-altering injuries due to a known safety issue that occurs just rarely enough that they're willing to pay a handful of those settlements rather than recall and fix what's out there on the road. When it comes to these mega corporations it really is about the bottom dollar and nothing more. We shouldn't have any illusions that they care one bit for the consumer the way a small business like yours does. We're not even the customer. Only the shareholder matters.

I can come up with a zillion what ifs. That doesn't change that generally it hasn't been an issue and it took so long for what we use as "gasoline" to have an actual effect on the tolerances, it was long past any concerns about a safety problem. The frames in the salt belt rusted out faster and we both know how all the sniveling about a class action lawsuit over that went.

The sticking issue isn't 100%. That means that the possibility of someone getting into a fire problem is even more diminished. As far as us not knowing about it, I put the chances of that next to zero. Everything that affects a TJ that winds up in the news good or bad gets talked about. That one would not fly under the radar.

 

[MikekiM]

...drove away from the gas pump with the cap left on their bumper..

Sort of related to this topic..

If you run the TJ without a gas cap will it produce any codes?

I had a few Audi's and BMWs years back that would throw an EVAP code if you so much as looked at them crooked with the gas cap off.. Certainly if you started the vehicle and drove sans gas cap...

 

[freedom_in_4low]

Sort of related to this topic..

If you run the TJ without a gas cap will it produce any codes?

I had a few Audi's and BMWs years back that would throw an EVAP code if you so much as looked at them crooked with the gas cap off.. Certainly if you started the vehicle and drove sans gas cap...

My 99 did but it wasn't instant. Once I dropped the cap and it shattered, I drove straight to the nearest parts store and I think I made it a few blocks before the CEL came on, if at all... It's been about 7 years. I drove away once on my way to work and it definitely came on that time.

My LJ has the tether so I've never "tested" it.

 

[MountaineerTom]

Sort of related to this topic..

If you run the TJ without a gas cap will it produce any codes?

I had a few Audi's and BMWs years back that would throw an EVAP code if you so much as looked at them crooked with the gas cap off.. Certainly if you started the vehicle and drove sans gas cap...

I would think it would. My ‘06 had a P0446 (evap leak) code in early June a day or so after getting gas. I removed and reinstalled the gas cap, reset the code and it has t come back. It was the easiest thing to check of the suggested fixes.

 

[mrblaine]

I would think it would. My ‘06 had a P0446 (evap leak) code in early June a day or so after getting gas. I removed and reinstalled the gas cap, reset the code and it has t come back. It was the easiest thing to check of the suggested fixes.

The system has leak detection. There are parameters when it runs so it may throw a CEL quickly or some time later if it is outside the parameters.

 

[sab]

If you run the TJ without a gas cap will it produce any codes?

Yes, a missing gas cap should trigger a P0455-EVAP SYSTEM LARGE LEAK, but how those codes get triggered differs, depending on your PCM.

For a JTEC (up to, and including, 2004):

For an NGC (2005 and 2006):

 

[mrblaine]

Yes, a missing gas cap should trigger a P0455-EVAP SYSTEM LARGE LEAK, but how those codes get triggered differs, depending on your PCM.

For a JTEC (up to, and including, 2004):
View attachment 543227

For an NGC (2005 and 2006):
View attachment 543228

The set condition for the 05-06 reads like it was written by an engineer who has never once interacted with someone who speaks normal English.

 

[sab]

The set condition for the 05-06 reads like it was written by an engineer who has never once interacted with someone who speaks normal English.

1. I don't know about Chrysler (20 years ago), but most vehicle manufacturers employ technical writers, not engineers, to write the manuals. Usually, though, the editing process includes a review by the design engineer for that system. Depending on the relationship between the writer and the engineer, none, all, or a mix of the engineer's comments will be used in the final manual. So it is entirely possible that an engineer had nothing to do with that section (but unlikely).
2. I detest spelling errors (though I'm anything but immune from them, myself - there's likely one in this here post ), and there is a glaring error in that section. Shame on the writer for that!
3. Allow me to attempt to translate to normal English:

Set Condition: The engine computer turns the EVAP Purge Solenoid on. When on, the solenoid pumps air out of the fuel tank to create a vacuum. There is a pressure switch in the fuel system that is normally open. That switch closes at about 0.04 psi of negative pressure (just a tiny vacuum). When the engine computer gets the signal from the closed switch that there is a vacuum in the tank, it shuts the EVAP Purge Solenoid off and starts a timer. If it sees the pressure switch open within a pre-determined amount of time (because air is leaking back into the fuel tank), it sets a counter in the engine computer from 0 to 1. Then, the next time the "When Monitored" conditions are met, the same test is performed. If the same leak is detected, the counter in the engine computer changes from 1 to 2, and the P0455 code is triggered. If the leak is not detected, the counter changes from 1 to 0 and no code is triggered. Only when the test detects a leak two times in a row is the code triggered.

And there you go. Engineerese-to-English.

 

[freedom_in_4low]

The set condition for the 05-06 reads like it was written by an engineer who has never once interacted with someone who speaks normal English.

I've been the engineer in this interaction:

Tech support: hey can I get the sequence of operations for the new controller?
Engineer: I just have a shorthand developer version, nothing for external publishing yet. Some of it more closely resembles code than any recognizable human language.
Tech support: ok Cool can you send it to me?
Engineer: I can but you can't send it out. You and your guys can use it for troubleshooting but that's it. Give me a week and I can get you something to work with.
Tech support: go ahead and send what you have for now, thanks
Engineer: ok.... <sends document>
Tech support: <forwards to entire department without any of the cautions or context, who forward it to anybody that asks, internal or external>
Tech writer: <copies verbatim into manual>
Engineer: <proceeds to get questioned on it in perpetuity by people that never should have seen it, regrets being helpful>

 

[mrblaine]

1. I don't know about Chrysler (20 years ago), but most vehicle manufacturers employ technical writers, not engineers, to write the manuals. Usually, though, the editing process includes a review by the design engineer for that system. Depending on the relationship between the writer and the engineer, none, all, or a mix of the engineer's comments will be used in the final manual. So it is entirely possible that an engineer had nothing to do with that section (but unlikely).
2. I detest spelling errors (though I'm anything but immune from them, myself - there's likely one in this here post ), and there is a glaring error in that section. Shame on the writer for that!
3. Allow me to attempt to translate to normal English:

Set Condition: The engine computer turns the EVAP Purge Solenoid on. When on, the solenoid pumps air out of the fuel tank to create a vacuum. There is a pressure switch in the fuel system that is normally open. That switch closes at about 0.04 psi of negative pressure (just a tiny vacuum). When the engine computer gets the signal from the closed switch that there is a vacuum in the tank, it shuts the EVAP Purge Solenoid off and starts a timer. If it sees the pressure switch open within a pre-determined amount of time (because air is leaking back into the fuel tank), it sets a counter in the engine computer from 0 to 1. Then, the next time the "When Monitored" conditions are met, the same test is performed. If the same leak is detected, the counter in the engine computer changes from 1 to 2, and the P0455 code is triggered. If the leak is not detected, the counter changes from 1 to 0 and no code is triggered. Only when the test detects a leak two times in a row is the code triggered.

And there you go. Engineerese-to-English.

Minorly better. Where I am confused is the function of the two different methods of "pumps" in the system. The early system has a LDP or leak detection pump. The later system uses NVLD or natural vacuum leak detection. Both systems use a purge solenoid valve. I was not aware that they were anything but a simple valve that was open or closed and not an actual pump. The LDP is a pump that changes pressure in the system to check for leaks, the latter uses temperature to create a natural vacuum. What am I missing?

 

[sab]

Both systems use a purge solenoid valve. I was not aware that they were anything but a simple valve that was open or closed and not an actual pump.

You know, you're exactly right. I just "translated" it without stopping to read it. The purge solenoid is not a pump. It is just a valve. I guess what that says is the purge solenoid opens, and that allows the intake manifold vacuum to trigger the pressure switch by pulling the tank to a vacuum through the open purge solenoid valve.

Those are just the large EVAP leak tests, though, which is what a missing gas cap would trigger. There are actually three different tests (small, medium, and large) for leaks. Only the small leak test for the NGC PCM uses pressure changes from ambient temperature changes. The medium and large leaks tests are the same. I think only the time that the PCM monitors for a leak is different between them.

I have struggled for many years to understand these EVAP tests for many vehicles I've worked on, but there is scarce good information out there to understand what exactly is going on.

 

[MikekiM]

All good.. thank you all.
I figured that would be the case.

 

[mrblaine]

You know, you're exactly right. I just "translated" it without stopping to read it. The purge solenoid is not a pump. It is just a valve. I guess what that says is the purge solenoid opens, and that allows the intake manifold vacuum to trigger the pressure switch by pulling the tank to a vacuum through the open purge solenoid valve.

Those are just the large EVAP leak tests, though, which is what a missing gas cap would trigger. There are actually three different tests (small, medium, and large) for leaks. Only the small leak test for the NGC PCM uses pressure changes from ambient temperature changes. The medium and large leaks tests are the same. I think only the time that the PCM monitors for a leak is different between them.

I have struggled for many years to understand these EVAP tests for many vehicles I've worked on, but there is scarce good information out there to understand what exactly is going on.

I know almost nothing about how they work which is why I am easily confused.

 

[TeejMeister]

I'm late to the party, and now that specific fuel filler hose is not available. Does anyone know if the GM ACDelco 25828451 Original Equipment Fuel Tank Fill Hose will work? From what I can gather the Hose #15131046 is 10 inches long. The ACDelco #25828451 is 6.3 inches long. How did I deal with it for so long? I knew when to slow the pump, or mostly just had gas pour out the inlet. I thought it was due to the speed at which the gas was flowing into the tank.

Oops, I didn't read through all of the comments... let me check