Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen? (1 Viewer)

[Eyedaho]

I can not duplicate mine. Some hot days at sea level, some low elevation mountain driving, some regular driving on the highway on a 70° day. The worst was an 85° - 90° day on I-85 in north GA headed south. Could hear it at the gas station. Had an eighth of a tank or so left and it vented like an angry monster. Usually I just have high pressure and a faint gas smell.

When mine has been bad at the gas station, I have trouble getting any fuel into the tank because the pressure leaving the filler neck immediately trips the automatic shutoff.

I was starting to smell fuel more often towards the end of the summer, but seem to have solved that with a new gas cap. I'm guessing it got contamination in the over pressure relief from being actuated in dusty conditions? This won't solve the fuel boiling issue, but at least temporarily reduced the frequency of the fuel smell.

 

[nikoli]

'03 LC100 here... developed a very strong fuel smell last summer. The odor in the cabin was awful. I could smell gas outside at the rear of the vehicle. When I filled the tank there would be a small amount of actual fuel leak onto the driveway overnight. No leak if I didn't fill past 3/4. The odor was almost non-existent with less than 3/4 tank. Reputable Toyota shop in town could not find anything wrong and suggested pulling the tank out to troubleshoot further. So rather than do that I just ran with 3/4 tank until I saved up enough $$$ for LRA replacement tank.

At the beginning of March I had the entire system replaced, including the replacement tank from LRA (40 gallons). The shop that did the work said the CC and the lines that went to it was all completely rusted out, and the top of the tank appeared to be rusted too. I ran thru a few tanks of gas with the new system and everything seemed perfect while driving in my city/state... Omaha, NE (roughly 1,000 feet).

However, I am typing this message from a cabin near Silver Plume, Colorado... at roughly 9,700 feet. Somewhere in the mountains the smell came back. It seemed to happen when going up a steep grade while running the engine really hard to keep up with traffic on the interstate. Since then it has happened a few times after come back west (up hill) from visiting Georgetown... seems to only happen when I run above 4,000 RPM for a minute... that's when the smell comes up. It goes away pretty quick after I'm able to back off the gas and open up all the windows for a bit. The smell doesn't go away 100% but it's definitely far less substantial than when the engine is working hard.

FTR, I only use 91 with no ethanol. And that's all I've ever used. My LRA tank was a little over half full when the smell came back. I don't hear any "boiling" and haven't noticed any fuel leaking from anywhere. It's obviously not hot here either.

All I know is I hate this. There have been plenty of other idiosyncrasies with this vehicle that I've been able to excuse. But this fuel smell thing is a deal breaker. Not only is it not safe... which is bad enough... but it also makes the whole experience really low brow. Like I'm driving some POS beater that stinks up the joint, rather than a high end luxury SUV that I can be proud of, even if the sunroof leaks from time to time and the windows controls are moody. Nothing has ever made me want to sell this vehicle... but dumping all this $$$ into the fuel system only to have the problem come up on the trip I saved up for has got me thinking.

 

[DTC72]

The answer is in this thread. I had the problem. I followed the specific advice below after trying many other things.

Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?

I've had this issue with and without full Dissent skids. In fact the single worst time I had fuel boiling out of my filler neck was without any after market skids. So I've ruled that out as a main cause, it could however be a factor in making a vehicle without a properly maintained cooling...

forum.ih8mud.com

 

[2001LC]

'03 LC100 here... developed a very strong fuel smell last summer. The odor in the cabin was awful. I could smell gas outside at the rear of the vehicle. When I filled the tank there would be a small amount of actual fuel leak onto the driveway overnight. No leak if I didn't fill past 3/4. The odor was almost non-existent with less than 3/4 tank. Reputable Toyota shop in town could not find anything wrong and suggested pulling the tank out to troubleshoot further. So rather than do that I just ran with 3/4 tank until I saved up enough $$$ for LRA replacement tank.

At the beginning of March I had the entire system replaced, including the replacement tank from LRA (40 gallons). The shop that did the work said the CC and the lines that went to it was all completely rusted out, and the top of the tank appeared to be rusted too. I ran thru a few tanks of gas with the new system and everything seemed perfect while driving in my city/state... Omaha, NE (roughly 1,000 feet).

However, I am typing this message from a cabin near Silver Plume, Colorado... at roughly 9,700 feet. Somewhere in the mountains the smell came back. It seemed to happen when going up a steep grade while running the engine really hard to keep up with traffic on the interstate. Since then it has happened a few times after come back west (up hill) from visiting Georgetown... seems to only happen when I run above 4,000 RPM for a minute... that's when the smell comes up. It goes away pretty quick after I'm able to back off the gas and open up all the windows for a bit. The smell doesn't go away 100% but it's definitely far less substantial than when the engine is working hard.

FTR, I only use 91 with no ethanol. And that's all I've ever used. My LRA tank was a little over half full when the smell came back. I don't hear any "boiling" and haven't noticed any fuel leaking from anywhere. It's obviously not hot here either.

All I know is I hate this. There have been plenty of other idiosyncrasies with this vehicle that I've been able to excuse. But this fuel smell thing is a deal breaker. Not only is it not safe... which is bad enough... but it also makes the whole experience really low brow. Like I'm driving some POS beater that stinks up the joint, rather than a high end luxury SUV that I can be proud of, even if the sunroof leaks from time to time and the windows controls are moody. Nothing has ever made me want to sell this vehicle... but dumping all this $$$ into the fuel system only to have the problem come up on the trip I saved up for has got me thinking.

I'm sorry you're having so many issues. But you need to understand a few things:.
1) Age & miles. 100 series or not, age has many effects. First being many hands have touch it (messed stuff up).
2) Rust! A rusty rig based, has special consideration. Some buy rust to save $$ on PP, others just don't know better. But they can be very problematic. First being rusts holes in under body, giving exhaust avenue into cabin.
3) Modifying a highly engineered vehicle like the 100 series. Issues will come up, and so will cost. In-fact some Dealership and INDY shops, will not help solve issues, when vehicle modified.

But all not lost. But depending on mods and extent of rust. You may head down an expensive road. Make sure you've a 100 series worth putting money into. I look at under body. If I see any rust in body seams, I don't feel worth much. If you feel your 100 worth put money into, to restore to what it should be. Then start with basics. Record engine coolant temps and fuel trims while driving (dash gauge useless). Once you've basics inline. You'll likely need to replace charcoal canister (CC). This assume you had a fuel boiling event or overfill gas tank, even once. As once CC flooded, they just don't work will again.

 

[Sventvkg]

I'm sorry you're having so many issues. But you need to understand a few things:.
1) Age & miles. 100 series or not, age has many effects. First being many hands have touch it (messed stuff up).
2) Rust! A rusty rig based, has special consideration. Some buy rust to save $$ on PP, others just don't know better. But they can be very problematic. First being rusts holes in under body, giving exhaust avenue into cabin.
3) Modifying a highly engineered vehicle like the 100 series. Issues will come up, and so will cost. In-fact some Dealership and INDY shops, will not help solve issues, when vehicle modified.

But all not lost. But depending on mods and extent of rust. You may head down an expensive road. Make sure you've a 100 series worth putting money into. I look at under body. If I see any rust in body seams, I don't feel worth much. If you feel your 100 worth put money into, to restore to what it should be. Then start with basics. Record engine coolant temps and fuel trims while driving (dash gauge useless). Once you've basics inline. You'll likely need to replace charcoal canister (CC). This assume you had a fuel boiling event or overfill gas tank, even once. As once CC flooded, they just don't work will again.

Is there a thread on replacing charcoal canisters?

 

[2001LC]

Is there a thread on replacing charcoal canisters?

IDK. You'll need to search. But they're not difficult. But as with all services, use the FSM.

 

[nikoli]

I'm sorry you're having so many issues. But you need to understand a few things:.
1) Age & miles. 100 series or not, age has many effects. First being many hands have touch it (messed stuff up).
2) Rust! A rusty rig based, has special consideration. Some buy rust to save $$ on PP, others just don't know better. But they can be very problematic. First being rusts holes in under body, giving exhaust avenue into cabin.
3) Modifying a highly engineered vehicle like the 100 series. Issues will come up, and so will cost. In-fact some Dealership and INDY shops, will not help solve issues, when vehicle modified.

But all not lost. But depending on mods and extent of rust. You may head down an expensive road. Make sure you've a 100 series worth putting money into. I look at under body. If I see any rust in body seams, I don't feel worth much. If you feel your 100 worth put money into, to restore to what it should be. Then start with basics. Record engine coolant temps and fuel trims while driving (dash gauge useless). Once you've basics inline. You'll likely need to replace charcoal canister (CC). This assume you had a fuel boiling event or overfill gas tank, even once. As once CC flooded, they just don't work will again.

Thanks for the response. It means a lot to me when others take the time to respond.

My wife purchased this '03 LC a couple years ago because she wanted a dog hauler and it "looked cool". She bought it "cheap" (LOL) with 202k on the clock, from some crappy small lot on the east coast while on on vacation, canceled her return flight and drove it home instead. It was a total POS with east coast rust and obvious neglect from previous ownership. However, she loves the thing and so we've done a TON of work on it... primarily done by a highly reputable Toyo shop. Initially they said it's not worth turning it into an overland/offroad rig due to the rust... but that it would be a fine dog hauler. It has been great for the most part and has reliably gotten us all over the midwest and CO... sitting at 213k now. We've had some significant work done on the brakes, ABS, rear suspension, etc. (FWIW, the LRA tank is the only non-OEM part on this thing.)

Now with the LRA tank and all the ancillary fuel system components (pump, CC, lines, etc) I guess what I'm trying to say is the money is already sunk. I was hoping to use the LC and LRA tank to tow my old Porsche between home and family cabin in the summer. It's a 3 hour drive into Iowa, no elevation but it will be hot in the summer. Now it sounds like this would be a risky and unpleasant proposition with the LC. I was really looking forward to making use of the 40 gallon tank in this context.

So the CC is brand new. That's maddening to hear it's very possibly shot already, esp considering how expensive the dumb thing is. Question... is that what we are smelling?

 

[AlpineAccess]

Thanks for the response. It means a lot to me when others take the time to respond.

My wife purchased this '03 LC a couple years ago because she wanted a dog hauler and it "looked cool". She bought it "cheap" (LOL) with 202k on the clock, from some crappy small lot on the east coast while on on vacation, canceled her return flight and drove it home instead. It was a total POS with east coast rust and obvious neglect from previous ownership. However, she loves the thing and so we've done a TON of work on it... primarily done by a highly reputable Toyo shop. Initially they said it's not worth turning it into an overland/offroad rig due to the rust... but that it would be a fine dog hauler. It has been great for the most part and has reliably gotten us all over the midwest and CO... sitting at 213k now. We've had some significant work done on the brakes, ABS, rear suspension, etc. (FWIW, the LRA tank is the only non-OEM part on this thing.)

Now with the LRA tank and all the ancillary fuel system components (pump, CC, lines, etc) I guess what I'm trying to say is the money is already sunk. I was hoping to use the LC and LRA tank to tow my old Porsche between home and family cabin in the summer. It's a 3 hour drive into Iowa, no elevation but it will be hot in the summer. Now it sounds like this would be a risky and unpleasant proposition with the LC. I was really looking forward to making use of the 40 gallon tank in this context.

So the CC is brand new. That's maddening to hear it's very possibly shot already, esp considering how expensive the dumb thing is. Question... is that what we are smelling?

I would go through the list of items for the boiling gas problem - seems like most people resolve it with very minimal expense (heat shielding and some tune up stuff).

Many of us have similar or higher mileage and don't have any concerns driving and towing when it's hot out. My 100 stays cooler than most vehicles I've owned and handles warm temps very well, but it did take some refreshing and tune ups to get it there (it's 24 years old after all).

Our dog like it as well! Great dog hauler!

 

[nikoli]

Thanks Alpine, you're right... I should do some of things that have helped others in this thread.

After reading more of this thread, it seems like there are bandaids that effectively address the symptoms, while there is still open debate on the cause.

Yesterday I used my bluetooth OBDII widget to the get the ECT while driving between Silver Plume (9,700ft where we are staying) and Georgetown (8,500ft)... it's about 3 miles between exits on i70.

Going downhill to Georgetown it never got above 196F. While in town it remained in the 190-200F range. It never seems to go under 190F.

Going up hill back towards Silver Plume it got up 212F... never went under 200F until I exited it the interstate. I was driving very conservatively this time, never going over 50mph. This kept the LC from getting into the 4k rpm range... which seems to be somewhat of a magic number for my truck. On our first trip when I was keeping up with traffic (65mph zone) it gets well into the 4k rpm range and stays there... and the gas smell happened.

So it would seem that my '03 LC runs hot, and we should work towards tuning so that we operate in the 180F range. I'm still uncertain the ideal ECT range is for my truck.

In the meantime I should probably do some shielding to bandaid the symptom.

For the trip I'm currently on, it seems best to keep it under 50mph while going uphill.

 

[AlpineAccess]

Thanks Alpine, you're right... I should do some of things that have helped others in this thread.

After reading more of this thread, it seems like there are bandaids that effectively address the symptoms, while there is still open debate on the cause.

Yesterday I used my bluetooth OBDII widget to the get the ECT while driving between Silver Plume (9,700ft where we are staying) and Georgetown (8,500ft)... it's about 3 miles between exits on i70.

Going downhill to Georgetown it never got above 196F. While in town it remained in the 190-200F range. It never seems to go under 190F.

Going up hill back towards Silver Plume it got up 212F... never went under 200F until I exited it the interstate. I was driving very conservatively this time, never going over 50mph. This kept the LC from getting into the 4k rpm range... which seems to be somewhat of a magic number for my truck. On our first trip when I was keeping up with traffic (65mph zone) it gets well into the 4k rpm range and stays there... and the gas smell happened.

So it would seem that my '03 LC runs hot, and we should work towards tuning so that we operate in the 180F range. I'm still uncertain the ideal ECT range is for my truck.

In the meantime I should probably do some shielding to bandaid the symptom.

For the trip I'm currently on, it seems best to keep it under 50mph while going uphill.

That seems too hot.

The ECT is right on the exit side of the engine leading into the thermostat. If you are staring into the engine bay from the front of the vehicle, and locate the radiator hose on the passenger side, you will see an aluminum housing with a neck that goes into the top of the hose. In that assemble is the thermostat, and between the hot engine and the thermostat is the sensor stuck into the top side of the housing.

Here's a pic from another thread:

100 - Serries coolant temperature sensor location

I searched and could not find the answer to this, so here is a picture of the location. Find where you put in the thermostat and follow the pipe straight back and the sensor is the first one you come to with the green top. You will need a 19mm deep socket, which is the type of socket you use to...

forum.ih8mud.com

Because of the location, the coolant temp at this spot is going to be virtually as hot as it possibly can get; which is why they stick it there (smart!).

That being said, even when worked really hard, the coolant should not be getting that hot. Not trying to be that guy and say "well mine doesn't do that" but it sounds like you do need a control group here for some results to compare it to. My LC just about religiously sits at 187-193. 187 is downhill in the winter, 193-195 maybe is holding high revs on a 100 degree day while towing.

I'd take stock of what's been done on the vehicle and look at making sure you've got a good thermostat, fresh/correct coolant, and making sure you have a radiator with less than 200k miles in there is a good start. I find spraying evap coil cleaner in my radiator and then hosing it down with water removes a LOT of crap that I never would have thought was in there. It's at every hardware store in the HVAC section.

These are winter time temperatures and it should not be struggling at all to stay cool, especially not towing. It sounds like its able to stay at a normal temp when not pushed super hard, which I would hazard a guess means the thermostat is opening at the right temp.

It COULD be:

1. Thermostat is not opening fully when super hot.
2. Radiator isn't cooling efficiently; old, dirty, etc.
3. SNOW/ICE blocking airflow over radiator!
4. Not bled properly, air pocket forming in system potentially near water pump (losing syphon so its not moving enough coolant)?
5. Congestion somewhere?
6. Something is up with the coolant. I'd guess certain coolant transfers heat to certain metal surfaces better than they do to others but I'm no fluids engineer.


Here is a thread where common engine temps are discussed; lots of people logging results.

2UZ-FE Normal Operating Temperature

Hi Mudders! I've searched the 100 series forums and couldn't find a definitive answer. What is the normal operating temperature for the 2UZ-FE during normal driving conditions? In cooler and warmer climates? I currently have a 98 with 169,000 miles still equipped with the original radiator...

forum.ih8mud.com

 

[nikoli]

That seems too hot.

The ECT is right on the exit side of the engine leading into the thermostat. If you are staring into the engine bay from the front of the vehicle, and locate the radiator hose on the passenger side, you will see an aluminum housing with a neck that goes into the top of the hose. In that assemble is the thermostat, and between the hot engine and the thermostat is the sensor stuck into the top side of the housing.

Here's a pic from another thread:

100 - Serries coolant temperature sensor location

I searched and could not find the answer to this, so here is a picture of the location. Find where you put in the thermostat and follow the pipe straight back and the sensor is the first one you come to with the green top. You will need a 19mm deep socket, which is the type of socket you use to...

forum.ih8mud.com

Because of the location, the coolant temp at this spot is going to be virtually as hot as it possibly can get; which is why they stick it there (smart!).

That being said, even when worked really hard, the coolant should not be getting that hot. Not trying to be that guy and say "well mine doesn't do that" but it sounds like you do need a control group here for some results to compare it to. My LC just about religiously sits at 187-193. 187 is downhill in the winter, 193-195 maybe is holding high revs on a 100 degree day.

I'd take stock of what's been done on the vehicle and look at making sure you've got a good thermostat, fresh/correct coolant, and making sure you have a radiator with less than 200k miles in there is a good start. I find spraying evap coil cleaner in my radiator and then hosing it down with water removes a LOT of crap that I never would have thought was in there. It's at every hardware store in the HVAC section.

These are winter time temperatures and it should not be struggling at all to stay cool, especially not towing. It sounds like its able to stay at a normal temp when not pushed super hard, which I would hazard a guess means the thermostat is opening at the right temp.

It COULD be:

1. Thermostat is not opening fully when super hot.
2. Radiator isn't cooling efficiently; old, dirty, etc.
3. SNOW/ICE blocking airflow over radiator!
4. Not bled properly, air pocket forming in system potentially near water pump (losing syphon so its not moving enough coolant)?
5. Congestion somewhere?
6. Something is up with the coolant. I'd guess certain coolant transfers heat to certain metal surfaces better than they do to others but I'm no fluids engineer.


Here is a thread where common engine temps are discussed; lots of people logging results.

2UZ-FE Normal Operating Temperature

Hi Mudders! I've searched the 100 series forums and couldn't find a definitive answer. What is the normal operating temperature for the 2UZ-FE during normal driving conditions? In cooler and warmer climates? I currently have a 98 with 169,000 miles still equipped with the original radiator...

forum.ih8mud.com

I would imagine it's primarily #2... I don't believe we've had the radiator replaced. Pretty sure the coolant has been flushed... think that was one of the first things we had done when my wife bought it. But looking at it, I see bent fins all over the place. So it's probably original and I sincerely doubt any previous owner ever did any cleaning. Probably we should plan on replacing.

We just drove back to Georgetown to do the Guanella Pass. Driving up the pass real slow, it never got over 208F. It was pretty much right at 200F the whole time. Put in low on the descent and it went back down to 190F range. On the drive back to cabin on i70 we stayed at 45mph up steep hills and 50mph when it leveled off... pretty much stayed right at 200F the whole time. Never went over 4k RPM at any point. Again, that seems to be the magic number for my truck since there was no gas smell.

In fact, the only times I really ever smell "engine smells" is when I start it. Doesn't smell like raw gas, just general "fumes" that I'd consider normal for an old truck with 213k on it.

One thing I haven't mentioned yet is we occasionally get P0420 and P0430 codes. And when I say "we" I really mean "I" because my wife says she's literally never seen the code when she's driving. She's only ever seen it when I drive it lol... and I drive it like a grandpa. (Seriously I love driving this thing slow). Idk whether those codes are related to the subject of this thread but figured it's worth mentioning. It's the only CEL we ever get since we fixed the ABS.

 

[AlpineAccess]

I would imagine it's primarily #2... I don't believe we've had the radiator replaced. Pretty sure the coolant has been flushed... think that was one of the first things we had done when my wife bought it. But looking at it, I see bent fins all over the place. So it's probably original and I sincerely doubt any previous owner ever did any cleaning. Probably we should plan on replacing.

We just drove back to Georgetown to do the Guanella Pass. Driving up the pass real slow, it never got over 208F. It was pretty much right at 200F the whole time. Put in low on the descent and it went back down to 190F range. On the drive back to cabin on i70 we stayed at 45mph up steep hills and 50mph when it leveled off... pretty much stayed right at 200F the whole time. Never went over 4k RPM at any point. Again, that seems to be the magic number for my truck since there was no gas smell.

In fact, the only times I really ever smell "engine smells" is when I start it. Doesn't smell like raw gas, just general "fumes" that I'd consider normal for an old truck with 213k on it.

One thing I haven't mentioned yet is we occasionally get P0420 and P0430 codes. And when I say "we" I really mean "I" because my wife says she's literally never seen the code when she's driving. She's only ever seen it when I drive it lol... and I drive it like a grandpa. (Seriously I love driving this thing slow). Idk whether those codes are related to the subject of this thread but figured it's worth mentioning. It's the only CEL we ever get since we fixed the ABS.

If the radiator is original you're going to find that is likely solving most of this issue. Dropping 20-25* of temperature is going to cool everything down a lot, but those clogged CATS are definitely a factor as well.

Albeit a messy project, the radiators on these things are a breeze to swap out. Thermostats are even easier. You can make sure the valve on the thermostat is at 12 o-clock so air bubbles and some coolant can bypass the valve (I see this wrong a lot). While you can TRY to save the coolant by using a drain hose from the petcock on the underside , but honestly its probably a good time to do a flush and get switched to Toyota Red or Pink if you have green or orange in there. No matter how much I try to keep my coolant clean when I drain it I always get crud in it and its ruined.

Also, most mechanics don't do a proper flush before switching to a new coolant type. They end up combining green/orange with red/pink which can lead to gelling, even if its in small amounts. Especially if they don't pull the block drains (almost never). Best to just flush it and go with what Toyota recommends as it plays well with the metals/seals/plastics they use and flush it a few times with distilled water between coolant types.

The second thing is that a clogged up cat will create very hot exhaust on the entry into the cats. Coincidentally that exhaust/cats are a lot closer to the fuel lines than maybe Toyota should have put them knowing the conditions most land cruisers are maintained/operated in around the world. That area gets pretty darn warm. If you actually put your hand in the bottom of your cup holder sometime you might get a feel for how much heat is hitting that transmission tunnel - that can be much hotter if you have cats that aren't flowing well.

You may consider running some cat-a-clean through and (once you get the new radiator in to keep things cool) give the thing some hard Italian tune ups. In Colorado those of us with the four speed 100's get italian tune ups every hard pull up the pass! Maybe you can find some cat-a-clean up in Summit County and use the rest of the trip to get things cleaned out!

 

[2001LC]

Flush coolant, R&R the thermostat & Rad Cap - use only Toyota here.
Replace bad vacuum lines.

#1 Clean the fins.

Radiator fins need cleaning! Alert Alert Alert

I've a 06LC w/192K I just bought. In reading history I found PO complained of engine temp raising when both front and rear AC on. Toyota Dealership diagnosed with clogged radiator fins. Recommended new OEM radiator, $600 for the US spec Radaitor plus coolant and labor. They should have added...

forum.ih8mud.com

 

[nikoli]

The second thing is that a clogged up cat will create very hot exhaust on the entry into the cats. Coincidentally that exhaust/cats are a lot closer to the fuel lines than maybe Toyota should have put them knowing the conditions most land cruisers are maintained/operated in around the world. That area gets pretty darn warm. If you actually put your hand in the bottom of your cup holder sometime you might get a feel for how much heat is hitting that transmission tunnel - that can be much hotter if you have cats that aren't flowing well.

You may consider running some cat-a-clean through and (once you get the new radiator in to keep things cool) give the thing some hard Italian tune ups. In Colorado those of us with the four speed 100's get italian tune ups every hard pull up the pass! Maybe you can find some cat-a-clean up in Summit County and use the rest of the trip to get things cleaned out!

Where do you suppose I could find a bottle? We might be headed towards Dillon tomorrow.

 

[rock climber]

Where do you suppose I could find a bottle? We might be headed towards Dillon tomorrow.

Walmart sells it

 

[2001LC]

Cataclean is found at most parts stores, or similar products. They're basically paint thinner. See:


Old CATs are not as effective as new. Which may result in some fuel smell, during lower RPMs, mostly idling. But it should not enter cabin, nor should exhaust fumes. Entering cabin, means excessive fumes and or a leak. Which fume leaks into cabin, can be body opening (rust holes) or rear side windows open. Even holes in exhaust (i.e. muffler) can enter cabin.

High altitude fuel smell, is most associated with fuel boiling. Which looking inside fuel door around gas cap, muck, is revealing of.

IMHO in every signal instance of fuel boiling or fumes:
1) The first order of business is to get ECT down. Washing Radiator (all 3) fins every 5K to 10K miles, since day that they were installed. Or more often, if driving though excessive air born debris (bugs, cotton, brasses, birds, dust, etc.). Is important and almost never done. I see more clogged rad fins, causing ECT issues than anything else. I've even found Styrofoam in-between condenser and engine radiators. I get shovels full of debris form out radiators during 2 hore washing. Even those large iron bumper & winches play a roll air flow & temps. If engine running hot, two issue devolve. 1) Fuel trims increase fuel in mixture (rich mixture). 2) Fuel lines get more radiant heat,than normally would.

2) Second order of business: Have a properly turned engine and transmission service.

Unfortunately; Any fuel boil (often from, excessive fuel tank pressure) or over-filling gas tank (NOT: stopping fueling at 1st auto pump handle shutoff) event. May damage the Charcoal Canister (CC,) which. Which we'll also get raw fuel smell from, and may also contribute to fuel boiling issues

Modified vehicle i.e. weight, shielding, fuel tank, fuel pump, fuel pressure regulator, return (EVAP) flows both raw fuel and vapor, etc. Also may play a roll here. Which I can't speak to, if modified.

 

[nikoli]

Cataclean is found at most parts stores, or similar products. They're basically paint thinner. See:


Old CATs are not as effective as new. Which may result in some fuel smell, during lower RPMs, mostly idling. But it should not enter cabin, nor should exhaust fumes. Entering cabin, means excessive fumes and or a leak. Which fume leaks into cabin, can be body opening (rust holes) or rear side windows open. Even holes in exhaust (i.e. muffler) can enter cabin.

High altitude fuel smell, is most associated with fuel boiling. Which looking inside fuel door around gas cap, muck, is revealing of.

IMHO in every signal instance of fuel boiling or fumes:
1) The first order of business is to get ECT down. Washing Radiator (all 3) fins every 5K to 10K miles, since day that they were installed. Or more often, if driving though excessive air born debris (bugs, cotton, brasses, birds, dust, etc.). Is important and almost never done. I see more clogged rad fins, causing ECT issues than anything else. I've even found Styrofoam in-between condenser and engine radiators. I get shovels full of debris form out radiators during 2 hore washing. Even those large iron bumper & winches play a roll air flow & temps. If engine running hot, two issue devolve. 1) Fuel trims increase fuel in mixture (rich mixture). 2) Fuel lines get more radiant heat,than normally would.

2) Second order of business: Have a properly turned engine and transmission service.

Unfortunately; Any fuel boil (often from, excessive fuel tank pressure) or over-filling gas tank (NOT: stopping fueling at 1st auto pump handle shutoff) event. May damage the Charcoal Canister (CC,) which. Which we'll also get raw fuel smell from, and may also contribute to fuel boiling issues

Modified vehicle i.e. weight, shielding, fuel tank, fuel pump, fuel pressure regulator, return (EVAP) flows both raw fuel and vapor, etc. Also may play a roll here. Which I can't speak to, if modified.

Thanks 2001LC

We didn't get around to driving towards Dillon today. Instead we hiked around our area. Then we went to drive towards Georgetown to get some dinner... and once we hit the on-ramp for i70 we started getting p0304.

Remember how I said above we hadn't gotten any other CEL codes? Whoops... jinxed it!

So we turned back around on the next exit and now I'm posting my problems here lol. It's definitely acting goofy. RPMs don't stay steady. Got us home okay though. But we've only got tomorrow left. Supposed to head back to Omaha on Thursday. Not sure if I should try a shop in Georgetown or try to get somewhere in Denver?

 

[Eyedaho]

If you're getting a misfire, that seems like you could be dumping unburned fuel into the cat and causing it to heat up. I'm not sure if a failing coil/plug related misfire would cause your RPMs to bounce around though, or if that indicates some other systemic fuel/air delivery issue or something.

 

[AlpineAccess]

Thanks 2001LC

We didn't get around to driving towards Dillon today. Instead we hiked around our area. Then we went to drive towards Georgetown to get some dinner... and once we hit the on-ramp for i70 we started getting p0304.

Remember how I said above we hadn't gotten any other CEL codes? Whoops... jinxed it!

So we turned back around on the next exit and now I'm posting my problems here lol. It's definitely acting goofy. RPMs don't stay steady. Got us home okay though. But we've only got tomorrow left. Supposed to head back to Omaha on Thursday. Not sure if I should try a shop in Georgetown or try to get somewhere in Denver?

Well, you might be in luck! Paul is just outside of Denver! (2001LC).

 

[nikoli]

Sorry I'm a newb here. How do I get in touch with @2001LC to coordinate a visit?

I'm in a bit of a pickle with the timing of all this... we're supposed to be out of the cabin Thursday (tomorrow) by 11am and headed back to Omaha.

Ideally I could drive to Denver and (hopefully) get this p0304 sorted today and then get back to cabin to pack up for return trip.