TheGrrrrr
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This current trip has been the worst so far. I’m committed to solving the problem so let me know what I can do to supplement your data and help find a solution.
Gas/Fuel vapors/fumes visible from gas door
- Thread starter kalieaire
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This current trip has been the worst so far. I’m committed to solving the problem so let me know what I can do to supplement your data and help find a solution.
Is there an obd fusion sensor for the fuel temp? At least 4 of the 7 of us had various boiling fuel issues today
Something like this might be promising. The F350 Super Duty has this somewhat simple fuel cooler on the fuel return line. Two of the ports for the the return line inlet and outlet (obviously), and the other two ports are for a secondary coolant system to send coolant through (to help bring the return fuel down to a more similar temperature). It gets bolted to the frame rail. A cooler like this could be attached wherever convenient (and safe) on the LC, and then the coolant lines could get routed to wherever the coolest air is (e.g., right behind the grille) and then attach an electric pump and a radiator with an electric fan. The main question would be how much heat could actually be transferred from the fuel to the coolant?
Amazon product ASIN B0BQ7QQFC2
Amazon product ASIN B0BQ7QQFC2
Not that I know of, and with a quick look at the engine nothing that appears to be a temp sensor on either of the fuel rails.
I don’t think the ECU being aware of fuel temp is as important in naturally aspirated port injection as it is direct, or with forced induction.
I will say almost 140f tank temp (based on what was flowing out of the pump) didn’t make a hint of odor in the panhandle at about 3k feet elevation. Whereas a full tank under 120f seemed to be boiling (or at least producing a whole lot of vapor and odor) at about 9800. Half ethanol-free on the latter observation.
VERY interesting.
Fluid/fluid coolers can transfer a tremendous amount of thermal energy.. we’d just need to figure out how much heat we’re removing and size the air-fluid exchanger appropriately. And add a coolant pump.. which in my experience will be the toughest part of this to make reliable.
I think the best thing to try first is pick the most reliable car brand (... Toyota?) and select an electric coolant pump from a model that has one (e.g., Prius). Probably will be the most reliable pump as long as it's a later generation model. The nice thing, even if the pump fails, it just means the vehicle reverts back to not cooling the return fuel (so worst case failure is that it reverts back to OEM functionality).
EDIT: Apparently VW & Audi (among others) also have secondary electric pumps for sending coolant to turbos. Not sure I'd want to go with theirs, but at least there are some reasonable options available.
One of my prior VWs had one. Usually 5/8-3/4” ports. I wonder whether restricting flow that much would be a problem. We’d see much lower temps and pressure than in those oem setups..
Interesting "4 of 7", not 7 of 7! Any differences, that account for only some boiling fuel.
Shouldn’t really have anything to do with boiling fuel as long as the cooling system of the truck can still keep up
What you're looking at in post #209 pictures, is 3 radiators. The largest in the background with cottonwood, leaves, bugs, dirt, brake and tire dust, grasses and all manner of road debris. Is the engine coolant radiator.
I can assure you, that in matters a great deal that fins of radiators all be keep clean.
Engine radiator is an integral part of coolant system. Reduce air flow through Rad fins, reduces cooling ability greatly.
I've lost count of just how many Land Cruiser/LX. That come to me running hot, were owner has no idea it is. They'll say, dash gauge looks normal, some needles even below mid-range.
I'll hook up to the OBD port and log ECT (engine coolant temp), as I drive in afternoon sun with front & rear AC on max cold. On a day perhaps, 90f to 100F OAT. I'll see ECT around 190F to 200f, depending on speed and yr. As I come to a stop, idling with foot on brake in D. I'll watch ECT climb to, 200- 220F, the drop back as I drive.
I'll service the coolant system. This service begins with washing radiator fins of debris. Often includes a new thermostat, rad cap, flush and make sure reservoir working as it should. Some, a new fan clutch is needed. ECT then drops to 194F to 197F (98-02 184F to 187F). Now with AC on and stopped idle in D. ECT stay under 200F (98-02 under 190F). I can drive all day, HWY speeds and at a crawl, still maintain proper operating temp (ECT).
I've wash shovels full of debris from radiators. Which to really get one not cleaned regularly, requires hours of washing over days. Dealership and most INDY, just replace the engine radiator when they find clogged. Which is best! But if one regular hose out debris, they clean much easier.
We must have coolant system working at peak at all times.
Will this correct all fuel boiling issues. NO! But it is a first step.
My fuel boiled 2k miles after a new radiator, the exact same way it does with 90k on that radiator.
It is painfully obvious a healthy cooling system is important for a reliable vehicle, but the discussion seems to be headed toward the only real solution for this being to remove heat from the fuel before it returns to the tank.
Mostly unrelated anecdote: a newer Mazda cx5 just drove past me at a ~9k foot mountain resort base, definitely never been off-road, and there was a serious cloud of fuel vapor following that thing.
It isn’t just Toyotas.
It isn’t just Toyotas.
My thoughts on this whole issue.
1st if it is a design error in the Land Cruiser (80,100 or 200). Then all would boil fuel. They don't! I know of many, both stock an built rigs. Running high altitude trials, without issue. So, it must be something happening after it leaves the factory. Which is my theory. But not just clogged Radiator fins, although that is so very common.
Once a fuel boiling episode has accrued, for whatever reason. Be it cylinder head temp, squeezing fuel pump handle one extra time after auto-shut-off (overfilling fuel tank), excessive CAT heat, EVAP issue, etc. The charcoal canister likely flooded, and if so will need replacing. If CC or EVAP system not releasing vapor/pressure, as it should. This can increase pressure in fuel tank.
We must correct whatever started the issues. Then replace EVAP components effected, if effected. Or it will continue to boil fuel.
My 80 boiled fuel just like my 200 does. I’ve read of plenty of 100s doing it.
I also believe the evap system is sophisticated enough to detect a CC that can no longer do its job, which is specifically why some people get codes. The evap/purge system is critical to emissions reduction and as such has a relatively high level of control, feedback, and error reporting.
Someone needs to experiment here on reducing fuel temps returning to the tank. Fuel temp is a fundamental contributor to boiling, and the only factor we can mess with. Pressure is the other and those limits will be set by Toyota with little opportunity to alter. As it stands we don’t know what portion of the elevated temps are radiant/convective from the tank being under the vehicle, vs added back to the tank via hot fuel from the engine bay/fuel rails.. but again, the hot returning fuel is one thing we can control.
I've yet to see a CC DTC in 100 or 200 series.
J2000 has done a lot of work with heat shielding and monitoring temps, in 100 series. He modified fuel system and intake. You can certainly check out what he's done. Then go down that road. It will benefit the issue (reduce fuel boiling) for sure.
Joey (Witends) siad. They found snorkel help lower IAT & ECT temps in 80 series. Also, that 8 of 10 new fan clutches he see, are weak. They need opening and thicker oil added. This also helps.
I'll recommended anyone have a fuel boiling issue. Run logs as they drive, logging FT, ECT, IAT, MPH, RPM, AFT & CAT temps. See what's going with engine & AT first. If they're running hot, correct first.
J2000 has done a lot of work with heat shielding and monitoring temps, in 100 series. He modified fuel system and intake. You can certainly check out what he's done. Then go down that road. It will benefit the issue (reduce fuel boiling) for sure.
Joey (Witends) siad. They found snorkel help lower IAT & ECT temps in 80 series. Also, that 8 of 10 new fan clutches he see, are weak. They need opening and thicker oil added. This also helps.
I'll recommended anyone have a fuel boiling issue. Run logs as they drive, logging FT, ECT, IAT, MPH, RPM, AFT & CAT temps. See what's going with engine & AT first. If they're running hot, correct first.
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@linuxgod can you think of any correlation between dorkel and lack of boiled fuel on the recent trails?
Or anyone else for that matter?
A snorkel would effectively take IATs off the table as a contributing factor.
Or anyone else for that matter?
A snorkel would effectively take IATs off the table as a contributing factor.
"snorkel" does not prevent fuel boil.
Found this article with this curve:
punchlistzero.com
I haven’t been following this thread too closely so sorry if this has already been posted.
From the curve, at 140F return temp, the gas would be about 20% vapor. At normal driving conditions this would probably not be an issue as the tank temp would be less and the evap system would be doing its thing.
Now add high altitude plus 100F+ ambient temp, and 3 mph wheeling up a mountain it’s easy to see how how well get some boiling.
So why do some have issues worse than others? IDK but mods are probably part of the equation. It makes sense to me that full BB style skids may trap enough heat that the tank doesn’t cool like OEM and the fuel return temp could even be higher.
Gasoline Boiling Point: Facts You Need to Know
In this article, you will learn the blends and compounds in gasoline, their effect on its boiling point, as well as pressure’s effect.
I haven’t been following this thread too closely so sorry if this has already been posted.
From the curve, at 140F return temp, the gas would be about 20% vapor. At normal driving conditions this would probably not be an issue as the tank temp would be less and the evap system would be doing its thing.
Now add high altitude plus 100F+ ambient temp, and 3 mph wheeling up a mountain it’s easy to see how how well get some boiling.
So why do some have issues worse than others? IDK but mods are probably part of the equation. It makes sense to me that full BB style skids may trap enough heat that the tank doesn’t cool like OEM and the fuel return temp could even be higher.