Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen? (2 Viewers)

[2001LC]

PM (Start a conversation) me, with your phone number. I'll text and or call ASAP.

What we know so far:
03 w/213K miles.
P0420 and P0430 codes on occasion.
Running hot. ECT hitting 208F during cooler weather. Running in the 190's in cooler weather.
Fuel smell at high altitude. Likely boiling fuel.
Non factory installed fuel tank.
Cylinder #4 misfire.

My guess:
Radiator fins clogged. Possible low coolant and or old, after market or improperly installed thermostat. Possible reservoir issues also.
Not properly tuned. i.e vacuum leaks, Spark plug(s) walking out. #4 Coil cooked. #4 spark plug may have blown out, or may be ready to.

Likely: That up-stream of CAT issue, have been going on for some time now, and getting worst. Likely excessive idling and or low RPM driving playing a roll in CAT codes. Whereas the 4.7L well suited for low RPM driving. It must be, well tuned to do so.

 

[nikoli]

PM (Start a conversation) me, with your phone number. I'll text and or call ASAP.

What we know so far:
03 w/213K miles.
P0420 and P0430 codes on occasion.
Running hot. ECT hitting 208F during cooler weather. Running in the 190's in cooler weather.
Fuel smell at high altitude. Likely boiling fuel.
Non factory installed fuel tank.
Cylinder #4 misfire.

My guess:
Radiator fins clogged. Possible low coolant and or old, after market or improperly installed thermostat. Possible reservoir issues also.
Not properly tuned. i.e vacuum leaks, Spark plug(s) walking out. #4 Coil cooked. #4 spark plug may have blown out, or may be ready to.

Likely: That up-stream of CAT issue, have been going on for some time now, and getting worst. Likely excessive idling and or low RPM driving playing a roll in CAT codes. Whereas the 4.7L well suited for low RPM driving. It must be, well tuned to do so.

Okay I sent you my name/number... hopefully I did it right

Everything else you said here seems to check out.

 

[2001LC]

Got it! Calling you now!

 

[nikoli]

Got it! Calling you now!

Thanks for speaking with me. It really means a lot to me. What a great community this is!

I was able to get from Silver Plume to Japanese Auto Services without issue (took it real easy on the hills). They were totally booked up for the day but they understood my situation and helped me out quickly. They confirmed the p0304 code was caused by a bad coil. They replaced with a denso unit they had on hand. Great bunch there... nice shop... friendly and fair. Drove back to Silver Plume without issue.

The next morning we packed up and drove to CostCo in Denver (Wadsworth street of i70) to fill up our LRA 40 gallon tank. (Yes there's ethanol in their gas). We then drove straight through to Omaha, 534 miles to our home... no issue, one tank of gas, and still have enough in the tank that the gas light didn't turn on! Averaged about 80mph, with two humans and two big dogs, a loaded yakima on the roof and a loaded trailer hitch carrier on the back... gotta love having 40 gallons in the tank! ECT sat at 206F pretty much the whole time.

Now that we're back home I'm going to work with a local shop to get our 03 LC100 tuned up and cooled down. I'm sure I'll be posting updates/progress on this site and asking lots of questions... probably lots of dumb ones, but hopefully mostly good ones lol.

 

[rock climber]

Thanks for speaking with me. It really means a lot to me. What a great community this is!

I was able to get from Silver Plume to Japanese Auto Services without issue (took it real easy on the hills). They were totally booked up for the day but they understood my situation and helped me out quickly. They confirmed the p0304 code was caused by a bad coil. They replaced with a denso unit they had on hand. Great bunch there... nice shop... friendly and fair. Drove back to Silver Plume without issue.

The next morning we packed up and drove to CostCo in Denver (Wadsworth street of i70) to fill up our LRA 40 gallon tank. (Yes there's ethanol in their gas). We then drove straight through to Omaha, 534 miles to our home... no issue, one tank of gas, and still have enough in the tank that the gas light didn't turn on! Averaged about 80mph, with two humans and two big dogs, a loaded yakima on the roof and a loaded trailer hitch carrier on the back... gotta love having 40 gallons in the tank! ECT sat at 206F pretty much the whole time.

Now that we're back home I'm going to work with a local shop to get our 03 LC100 tuned up and cooled down. I'm sure I'll be posting updates/progress on this site and asking lots of questions... probably lots of dumb ones, but hopefully mostly good ones lol.

Thanks for the update and glad you made it back!

I'm jealous of your LRA tank. I barely make it it up the mountains to vail before I need to fill up. Moab is 3 tanks of gas

 

[AFei]

So for all of those method to limit the heat into the gas lines and tank, has anyone tried to wrap the exhaust pipes including CAT and muffler with the fire resistant fibber fabric to actually reduce the radiation heat?

Thinking about this method for lower cost and easier installation. However, have the concern on if it may increase the exhaust system temperature which may cause any damage to components like CAT/muffler, negatively impact engine performance, or even damage the engine? Can anyone share their knowledge?

This is the product I'm talking about, and This post says it's good to the exhaust system.

Thanks!

 

[krispykritter]

So for all of those method to limit the heat into the gas lines and tank, has anyone tried to wrap the exhaust pipes including CAT and muffler with the fire resistant fibber fabric to actually reduce the radiation heat?

Thinking about this method for lower cost and easier installation. However, have the concern on if it may increase the exhaust system temperature which may cause any damage to components like CAT/muffler, negatively impact engine performance, or even damage the engine? Can anyone share their knowledge?

This is the product I'm talking about, and This post says it's good to the exhaust system.

Thanks!

I have not tried that, though I do use it on my team's racecar. I used some aluminum to extend the driver's side cat heat shield farther down, and then added a bunch of the aluminum/foam insulation stuff to the front and sides of the fuel tank. This stuff off amazon. It's pretty quick and easy to apply, and relatively cheap. That is all I've done.

I can say that doing only that made a huge difference. In 2021, I went to Canyonlands with some friends and spent virtually the entire trip watching my coolant temps (any period spent idling resulted in the coolant creeping up) and listening to my fuel tank boil - even got the dreaded non-start issue once. I also got a nice big red smear around my fuel filler door from the fuel fumes mixing with dirt and adhering to the 100.

That same year, after my trip, I put in a new fan clutch and aluminum radiator, and added the cat heat shield and fuel tank insulation. Then, we went back to Canyonlands in late 22. I STILL had the idling/crawling coolant temp rise issue despite my improved cooling system, but zero fuel-related issues. No boiling, no non-start, no fuel smell, nothing.

Edit: I just remembered my buddy was in his brand spanking new 22 4Runner and we had to deal with gas fumes from him, but not my 100. He was not thrilled.

Wrapping the exhaust pipes near the tank may help, I'm not sure. But I do know adding that adhesive insulation completely solved my fuel issues. Also, I hate dealing with the fiberglass insulation, and only use that stuff as a last resort.

 

[AFei]

I used some aluminum to extend the driver's side cat heat shield farther down, and then added a bunch of the aluminum/foam insulation stuff to the front and sides of the fuel tank. This stuff off amazon. It's pretty quick and easy to apply, and relatively cheap. That is all I've done.

Great to know. I will apply it also. Quick question: Before installation, do you have to clean/wash the area to remove dirty?

 

[krispykritter]

Great to know. I will apply it also. Quick question: Before installation, do you have to clean/wash the area to remove dirty?

I did clean that area as best I could while also being lazy. Pressure washer at a local diy car wash. It'll definitely help it stick to get any big chunks of dirt or grease off.

I used scissors to chop it into reasonable sized pieces and to get around corners and edges. I also double layered it where I could. It's not the prettiest installation but it's damn sure effective.

 

[AFei]

I used scissors to chop it into reasonable sized pieces and to get around corners and edges. I also double layered it where I could. It's not the prettiest installation but it's damn sure effective.

Besides of around the gas tank and adjacent area, any other place did you also install the shield?

 

[krispykritter]

Besides of around the gas tank and adjacent area, any other place did you also install the shield?

Nope, just slapped it all over the tank. Keep in mind, anything you stick on the bottom is likely to get scraped back off again but I don't think I've lost any on the sides yet. I paid special attention to the front inboard corner where the crossover pipe gets quite close to the tank. I made sure to coat the front side and inboard sides as best I could and left everything else expose, with the thought that the heat that does get into the fuel should have somewhere to escape to.

You could also buy something nicer or better than what I bought, or actually do a better job than I did! This was an experiment in some ways, but @J1000 was 100% right that is was the best bang for my time and money.

Here's the cat heat shield I made of scrap aluminum:

 

[2001LC]

Thanks for speaking with me. It really means a lot to me. What a great community this is!

I was able to get from Silver Plume to Japanese Auto Services without issue (took it real easy on the hills). They were totally booked up for the day but they understood my situation and helped me out quickly. They confirmed the p0304 code was caused by a bad coil. They replaced with a denso unit they had on hand. Great bunch there... nice shop... friendly and fair. Drove back to Silver Plume without issue.

The next morning we packed up and drove to CostCo in Denver (Wadsworth street of i70) to fill up our LRA 40 gallon tank. (Yes there's ethanol in their gas). We then drove straight through to Omaha, 534 miles to our home... no issue, one tank of gas, and still have enough in the tank that the gas light didn't turn on! Averaged about 80mph, with two humans and two big dogs, a loaded yakima on the roof and a loaded trailer hitch carrier on the back... gotta love having 40 gallons in the tank! ECT sat at 206F pretty much the whole time.

Now that we're back home I'm going to work with a local shop to get our 03 LC100 tuned up and cooled down. I'm sure I'll be posting updates/progress on this site and asking lots of questions... probably lots of dumb ones, but hopefully mostly good ones lol.

Great!

Get ECT down and engine tuned with proper parts (OEM/Denso). Will make a big difference in reliability. Most shops will not take the time to wash radiator fins. So you may want to do that yourself, before taking in. If drive belt or it's pulley bearings, past useful life. They'll like start squealing once you get wet. Shop can then replace them for you. Make sure the get all vacuum leaks stopped (new hoses).

 

[2001LC]

Anyone watch ECT?

 

[wsudu]

OK, I've read through this thread and I found bits and pieces but not the full picture, at least for me. I get a consistent check engine light with five evap codes shown below. I get the fuel smell, boiling, not starting issue in the summer and/or at high altitudes. Last, I get a finicky fuel gauge that shows empty when it is around 1/4 tank, but then eventually goes back to normal. She is tuned up, and runs well with no other issues. If you were me, where would you start? The fuel canister? Thank You

 

[krispykritter]

OK, I've read through this thread and I found bits and pieces but not the full picture, at least for me. I get a consistent check engine light with five evap codes shown below. I get the fuel smell, boiling, not starting issue in the summer and/or at high altitudes. Last, I get a finicky fuel gauge that shows empty when it is around 1/4 tank, but then eventually goes back to normal. She is tuned up, and runs well with no other issues. If you were me, where would you start? The fuel canister? Thank You



View attachment 3296047

Wow - hopefully someone can chime in with some info; I'm not helpful with that =(

That's a weird one, as most of those codes contradict the rest of those codes. I would guess you've got a major leak somewhere but it's a complete guess.

Might be helpful to post your model year.

 

[AFei]

#2: Moving return fuel line off the engine to the firewall. This just eliminated the steel return fuel line that is bolted directly to the engine cylinder heads on the rear of the engine reducing the amount of heat returned to the tank from the fuel rails. I also covered the fuel line as well as the rest of the lines with heatshield: Amazon.com: Design Engineering 010448 Cool-Tube Extreme Heat Reflective Sleeve, 0.75" x 9' - Black: Automotive - https://amzn.to/2ZZs0ds

Wondering how you relocated the fuel return line? Did you replace the factory steel one with rubber hose?

 

[augustwest]

I've been getting the P0420 and P0430 codes for a while now, and have been resetting them via the Torque app. On Saturday, I finally got around to running a bottle of cat-a-clean through it, and then this morning the dash lights up and I'm getting P0420 and P0430 again. The dash typically lights up 1-2x per day, so the 3 days I got out of it was longer than usual. Should I run some more cat-a-clean through it? Check the O2 sensors? Would really hate to have to spring for new cats.

 

[2001LC]

I've been getting the P0420 and P0430 codes for a while now, and have been resetting them via the Torque app. On Saturday, I finally got around to running a bottle of cat-a-clean through it, and then this morning the dash lights up and I'm getting P0420 and P0430 again. The dash typically lights up 1-2x per day, so the 3 days I got out of it was longer than usual. Should I run some more cat-a-clean through it? Check the O2 sensors? Would really hate to have to spring for new cats.

What year and miles?
I'll guess 06-07 150k to 250K miles!

 

[krispykritter]

What year and miles?
I'll guess 06-07 150k to 250K miles!

Oh pls no I really don't need more failures in the near future!

 

[2001LC]

Oh pls no I really don't need more failures in the near future!

IMHO all 06-up, all makes and models. Need action taken w/S.A.I. or they kill the CATs and more.

S.A.I. Modification in VVT engines to prevent its failure! Alert Alert

We've a $2.00 part in the S.A.I.S. of the VVT engine, 1s taking-out ~$7,000.00 $15,000 (inflation) in parts. WOW! I've a very easy and cheap WORK AROUND. You are going to love this ;) This thread is dedicated to the 4.7L 2UZ-fe VVT engine, in the 2006 & 2007 100 series Land Cruiser & Lexus...

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