Just throwing in my $.02; when I went to Moab from California, I put in that Ethanol 95 stuff. They don't distribute that here in CA, so I've never used it before. But let me tell you, there was a huge difference when I went to refill after running a tank of it. It spewed for 30+ seconds and got all over. Now that I'm back in CA putting non-Ethanol, I've not had a recurrence.
Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen? (3 Viewers)
- Thread starter 2001LC
- Start date
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Eyedaho
SILVER Star
I'm a little confused about what you're saying. California has ethanol gas blends. If you're referring to E85, you should not be putting that in your 100 series. That stuff is for flex fuel vehicles, or vehicles that have been modified to run on it. It seems like you might want to read up on the various ethanol blends of gasoline?
2001LC
SILVER Star
- Thread starter
- #343
With covid slowing all auto, ship and airline jet fuel demand. Refiners drop to ~60% of capacity (normal in spring/early summer is 94 to 97%). Interesting too, they've been re-refining jet fuel into gasoline, to reduce glut of jet fuel. With so many business including gas station hurt by shutt downs and slow downs. It very likely, some less than honorable, added addition ethanal and even water, to boost profits.
The amount of water in @CUBuffs fuel pump was very strange. He drives regularly and buys from newer gas stations (newer the storage tanks, less chance of groundwater) for the most part. Speaking with BG with regards to their fuel drier product. He said; They've not been selling much Fuel Drier these days, since ethanol was mandated.
This could be the return tube. Perhaps your serpresor/anti-siphon boot fell off and sound is louder.
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Yeah I don’t remember seeing that orange piece you circled in your photo... How bad is it to run without that orange piece?
2001LC
SILVER Star
- Thread starter
- #345
IDK. It's just a soft rubber nipple, with a slit in the end. Seem like it to would allow fuel into tank easy, but make difficult to come out or rather back into the return line. It likely has effect of deadening sound, as fuel passes somewhat restricted into fuel tank.
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Non Ethanol gas test:
Decided to try a tank of non ethanol today, same trail run I've been testing on, 8600 - 9000 FT, today was a little cooler - 79 vs 81 OAT.
Filled up in Denver area with 22.1 gallons of non ethanol and headed up to the trail, which is 55 miles away. ECT range was 185 - 203.
Stopped about 30 mins into the trail and could smell gas and see vapor from the cap.
Shut engine off, waited 5 mins, restarted, it had a rough idle and stalled maybe 20 seconds later. restarted it right away and seemed fine, I let it idle for 5 mins, during that 5 mins a couple times it would drop rpm pretty low, but didn't stall.
After 5 mins of idle running, I shut it off again. Let it sit off for 5 mins, restarted it - again rough idle and stall in 20 seconds. Restarted right away and was ok, idle would drop down a couple times but kept running. Drove a few hundred feet and felt fine.
I then shut it off again, removed the gas cap for one minute, could hear some boiling noise, then tried to restart. No start after multiple tries. Waited 5 mins, still no start on multiple attempts. Waited another 5 minutes and it started right up.
Didn't have as much time today to keep testing, but back at the trail head I did one last shut down, let it sit for 5 minutes, and it started up fine. Could still smell gas, and see vapor from the cap.
When I got back home, I didn't smell gas, or see any vapor coming from the cap area, which I did on previous runs.
So at least for me, non ethanol wasn't much better... maybe a little...
Also got probably .75 MPG better on the non ethanol. Will have to see how the rest of the tank goes.
Decided to try a tank of non ethanol today, same trail run I've been testing on, 8600 - 9000 FT, today was a little cooler - 79 vs 81 OAT.
Filled up in Denver area with 22.1 gallons of non ethanol and headed up to the trail, which is 55 miles away. ECT range was 185 - 203.
Stopped about 30 mins into the trail and could smell gas and see vapor from the cap.
Shut engine off, waited 5 mins, restarted, it had a rough idle and stalled maybe 20 seconds later. restarted it right away and seemed fine, I let it idle for 5 mins, during that 5 mins a couple times it would drop rpm pretty low, but didn't stall.
After 5 mins of idle running, I shut it off again. Let it sit off for 5 mins, restarted it - again rough idle and stall in 20 seconds. Restarted right away and was ok, idle would drop down a couple times but kept running. Drove a few hundred feet and felt fine.
I then shut it off again, removed the gas cap for one minute, could hear some boiling noise, then tried to restart. No start after multiple tries. Waited 5 mins, still no start on multiple attempts. Waited another 5 minutes and it started right up.
Didn't have as much time today to keep testing, but back at the trail head I did one last shut down, let it sit for 5 minutes, and it started up fine. Could still smell gas, and see vapor from the cap.
When I got back home, I didn't smell gas, or see any vapor coming from the cap area, which I did on previous runs.
So at least for me, non ethanol wasn't much better... maybe a little...
Also got probably .75 MPG better on the non ethanol. Will have to see how the rest of the tank goes.
Pretty sure the stalling and no-start is due to vapor lock. The fuel in the lines needs to stay pressurized, otherwise with the heat and altitude you will get pockets of vapor in the fuel lines. The more it sits, pressure in the lines will drop and with no air flow or fuel flow to keep the fuel rails cool, the heat soaked engine will heat the fuel rails, fuel filter, etc. increasing chance of vapor. This can happen up until the point that the engine and fuel all cools enough for fuel in the lines to return to liquid.
I'm guessing that opening the gas cap also contributes to dropping pressure in the fuel feed lines, increasing likelihood of vapor lock. Lower pressure = lower transition temperature. I haven't read to see if you have a newer fuel pump, but lower operating pressures in the fuel lines, or a warn pump allowing pressure to drop after shutoff will probably also increase likelihood of vapor lock.
Not poking at anybody here, but I honestly don't understand the logic for removing gas cap and venting the fuel tank. I don't think it helps the fuel system cool significantly faster. I think it increases chances for vapor lock, and I definitely think it increases the risk of hazards.
I'm guessing that opening the gas cap also contributes to dropping pressure in the fuel feed lines, increasing likelihood of vapor lock. Lower pressure = lower transition temperature. I haven't read to see if you have a newer fuel pump, but lower operating pressures in the fuel lines, or a warn pump allowing pressure to drop after shutoff will probably also increase likelihood of vapor lock.
Not poking at anybody here, but I honestly don't understand the logic for removing gas cap and venting the fuel tank. I don't think it helps the fuel system cool significantly faster. I think it increases chances for vapor lock, and I definitely think it increases the risk of hazards.
I thought about that exactly, the few times I experienced this, and that was the conundrum: reduce pressure and increase the chance of vapor forming in the fuel line, or reduce pressure, and hope the evaporation in the main tank (sorry VOCs) will cool it enough that cycling the fuel pump a few times in half hour will pump liquid through the entire supply. In short, I can't say one causes the other, but the correlation was hard to ignore in a panicked state of mind.
ramangain
Clarksonian disciple
I had the fuel cap fumes events happen recently in AZ and CA when temps were 105+F. I wasn't at elevation. After filling up, my rig took 3-5 seconds of cranking to catch and run, but it always caught and ran without any stalling or bogging issues.
Anyone thought of installing a couple of TEC coolers and blowing the cooler air down on top of the gas tank to try and help a bit?
Anyone thought of installing a couple of TEC coolers and blowing the cooler air down on top of the gas tank to try and help a bit?
I didn't yesterday, but after a 40 mile city drive today.. it was the same (hot).
Had a new fuel pump and filter installed last week.. I also think it is a vapor lock type of issue, maybe by the belly plate trapping heat from the cats next to the fuel lines
Yeah - I would not recommend removing the gas cap either, was just testing some theories I've seen - in the times I've tried it led to longer wait times before I could restart.
Thank you so much for documenting your progress addressing this issue. I've been following pretty closely and built a heatshield as well based off of your process. I tried drilling the last screw closest to the engine bay, but could not reach it. Did you just drop the heatshield and install the sheet metal off the truck? Also, correct me if I'm wrong, but aren't you just wrapping the AHC lines here? Arent the fuel lines running higher? Did you happen to take pictures of how you wrapped it? Thanks!
No, the lines shown in my photo are the fuel lines, the AHC lines are above and have a black coating on them already. I was able to drill all of the holes with everything in place on the truck. I used on of these super-handy 90 degree drills: https://amzn.to/2Yjb0NV
Things are going really good with my truck. Drove around town and then to Boulder and back. Doesn't really get any better than this. I was initially shocked and had to double check all of my numbers.
No, the lines shown in my photo are the fuel lines, the AHC lines are above and have a black coating on them already. I was able to drill all of the holes with everything in place on the truck. I used on of these super-handy 90 degree drills: https://amzn.to/2Yjb0NV
Things are going really good with my truck. Drove around town and then to Boulder and back. Doesn't really get any better than this. I was initially shocked and had to double check all of my numbers.
Awesome! Glad to hear, thanks for the tip.
On my truck '05 LX, the fuel/vapor lines are higher & run next to each other. So 4 lines all next to each other (2 going 2 coming back).
It was easy to just take the original heat shield off & attach the new one & then just reinstall. Although I did mess up the holes alignment & drilled 8 holes where I only needed 2 ( Don't ask how, I have this knack).
I also applied heat shielding on the return lines in the engine bay, in the hopes on reducing heat to the tank.
That's what I thought - that the fuel lines are the 4 lines running in parallel with each other, because when I traced the two larger lines it routed to the AHC globes - same with the passenger side. Glad the heat shield was easy to take off, I was worried that if I took them off, it would be a PITA to put back on. Thanks for the info, did the shielding end up helping for you? I have yet to test at altitude
Have not tested yet, but I'll report back hopefully soon.
Here's some non-scientific personal experience information that might be helpful to others experiencing this problem. 2 weeks ago, my LC had this issue and I think I have since solved it.
1999 LC with about 255k miles, brand new OEM radiator, hoses, topped up with OEM coolant, new heater tees, and brand new OEM gas cap; factory original carbon canister in the engine compartment; generally running 185-195 F coolant temps
When I first had this issue, I was driving up to about 10k elevation in the Eastern Sierras from Owens Valley starting with a full tank of 91 octane gas which was 10% ethanol. The OAT in Owens Valley was 100F. By the time I got up to 10k elevation, I had some fuel odor in the passenger compartment, some dirt staining around the gas cap, and fuel odor coming from the EVAP canister in the engine bay. I loosened the gas cap and it immediately began venting lots of pressure and fuel vapors. I closed the gas cap. I did not have any issues starting the truck and no engine shutdown.
After that trip, I made the following changes to the truck. I replaced all the EVAP hoses in the engine compartment and the PCV valve. The rubber was old and cracking. The plastic grommet for the PCV practically fell apart on removal as well. I also used 36" long x 3" wide velcro heat wrap from Amazon and wrapped the hard fuel lines as they passed the catalytic converter on the driver's side.
This past weekend, I drove back up to 10k elevation with OAT in the valley of 100 F again. Same fuel and full tank. This time, no fuel smell inside or outside the truck and no dirt/fuel residue around the gas cap. I did not burp the gas cap to check, but I'm guessing fuel pressure was just fine since there was no venting from the EVAP or gas cap.
List of EVAP related hoses/parts replaced:
Everything in the Wit's End PCV Kit 100 Series 2UZ PCV Kit- 1/1998-4/2005
12204-50020 - Valve, ventilation
90480-18001 - PCV grommet
12235-50010 - Vent Cap
12236-50010 - Vent valve cover
12261-50050 - Vent hose
12262-50080 - Vent hose
Plus the following
17341-50110 - Hose, Air
17030-50070 - Hose, No 1 (Idle-up)
23829-50070 - Hose, Fuel Vapor
Photos of my poorly executed fuel line wrap:
1999 LC with about 255k miles, brand new OEM radiator, hoses, topped up with OEM coolant, new heater tees, and brand new OEM gas cap; factory original carbon canister in the engine compartment; generally running 185-195 F coolant temps
When I first had this issue, I was driving up to about 10k elevation in the Eastern Sierras from Owens Valley starting with a full tank of 91 octane gas which was 10% ethanol. The OAT in Owens Valley was 100F. By the time I got up to 10k elevation, I had some fuel odor in the passenger compartment, some dirt staining around the gas cap, and fuel odor coming from the EVAP canister in the engine bay. I loosened the gas cap and it immediately began venting lots of pressure and fuel vapors. I closed the gas cap. I did not have any issues starting the truck and no engine shutdown.
After that trip, I made the following changes to the truck. I replaced all the EVAP hoses in the engine compartment and the PCV valve. The rubber was old and cracking. The plastic grommet for the PCV practically fell apart on removal as well. I also used 36" long x 3" wide velcro heat wrap from Amazon and wrapped the hard fuel lines as they passed the catalytic converter on the driver's side.
This past weekend, I drove back up to 10k elevation with OAT in the valley of 100 F again. Same fuel and full tank. This time, no fuel smell inside or outside the truck and no dirt/fuel residue around the gas cap. I did not burp the gas cap to check, but I'm guessing fuel pressure was just fine since there was no venting from the EVAP or gas cap.
List of EVAP related hoses/parts replaced:
Everything in the Wit's End PCV Kit 100 Series 2UZ PCV Kit- 1/1998-4/2005
12204-50020 - Valve, ventilation
90480-18001 - PCV grommet
12235-50010 - Vent Cap
12236-50010 - Vent valve cover
12261-50050 - Vent hose
12262-50080 - Vent hose
Plus the following
17341-50110 - Hose, Air
17030-50070 - Hose, No 1 (Idle-up)
23829-50070 - Hose, Fuel Vapor
Photos of my poorly executed fuel line wrap:
I noticed my catalytic making noise what guys think about the Magnaflow universal ofcourse the cali version
no engine light but rattles.
no engine light but rattles.
