This is absolutely not true. You can search this very forum as find people having this fuel boiling problem with 100s as long ago as this forum existed.
Gas tank building excessive pressure & fuel smell. Dangerous for sure! Why does this happen?
- Thread starter 2001LC
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@J1000 You misinterpreted my post. I'm not arguing the use of E85, E10 or whatever. My only point was running the fuel pump on full blast will contribute to increasing the temperature through heat of the pump and friction in the lines. Simple, I know. Nikoli comes along and says it's a flawed test due to E85 and what not. It doesn't matter what fuel one is using, running the pump on full bore will not help. Best to leave it alone. I'm done here.
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Prove it. I don't believe it. I already mentioned the reasons why.
FWIW, had no pressurization in the tank for 800 miles. Just pulled into an unusually warm Wichita (80F) and it was fully pressurized when refueling. I had topped up 4 times prior with no pressure build up, just weird how intermittent it can be.
this rumor of two speed pump annoys me.
it's variably controlled by a lump of aluminum that fluctuates with temp to maintain a certain supplied voltage in a certain range. Consequently, volume output is lessened while maintaining the pressure spec.
www.epa.gov/gasoline-standards/ethanol-waivers-e15-and-e10 starting point, I think.
100% sure the 100 was not engineered to run on e15, including future changes to fractional makeup or any waivers for rvp, even if only 1 degree on paper.
I can't even imagine the conversation if 100's were carbureted or were twin turbo 8's.
or pressure washing the 3 radiators on new gx, sequoia, tundra.
please, everyone, sell your 100s and 200s before you miss out on this fabulous market toyota has planned.
all the landcruisers are just ticking time bombs.
long live the 3ur 2uz 1gr 1ur
it's variably controlled by a lump of aluminum that fluctuates with temp to maintain a certain supplied voltage in a certain range. Consequently, volume output is lessened while maintaining the pressure spec.
www.epa.gov/gasoline-standards/ethanol-waivers-e15-and-e10 starting point, I think.
100% sure the 100 was not engineered to run on e15, including future changes to fractional makeup or any waivers for rvp, even if only 1 degree on paper.
I can't even imagine the conversation if 100's were carbureted or were twin turbo 8's.
or pressure washing the 3 radiators on new gx, sequoia, tundra.
please, everyone, sell your 100s and 200s before you miss out on this fabulous market toyota has planned.
all the landcruisers are just ticking time bombs.
long live the 3ur 2uz 1gr 1ur
- Thread starter
- #946
Wrong!
Sure we can find some in this microcosm of 100s, with fuel boiling issues. But, by no means does that mean all.
Today I own four 100s. Over last 21 years, I've owned about 20 of them. Ranging from 1998-2007 with mileages from 45K to 380K miles. Not one boiled fuel, when it left here/my ownership. Only one had evidence (gunky fuel fill/cap area), it may have once boil fuel before I owned it. So in my, microcosm of ownership of 100, that only 5% even showed a possible sign, it may have once boiled fuel.
But you also don't tow or go off-road or drive across country so how would you know?
FYI, mine has had the boiling/vapor lock issue. I'm sure it will still happen as I have done nothing to mitigate it. I don't put the truck in the situation enough to consider it a problem I need to address at this point. Not to belittle it as boiling fuel is a terrifying thing. It has happened in the typical situations of slow, bouncy 4x4 warm weather driving that gain considerable altitude. I've kept my truck where you put it at 100% in factory spec, other than the TT spark plugs(which I installed after the times it happened). This isn't a comment against you or your meticulous attention to detail with your work on my rig or any of the others you have had. In fact, all your observations are correct in that they will help contribute to the boiling happening. I'm just putting my experience out there as a data point. Factory spec will get the truck to the best chance at not boiling but is not a 100% guarantee that it won't happen.
There is no single reason for this problem. There have been a few solutions on here that have worked for some but don't show as the main reason as not everyone has had the same success.
At this point, I believe the main factors for this are:
- These trucks weren't designed for ethanol fuel. So the baseline from which we start is skewed right there.
- Agitating the fuel in the off-road scenario adds to that.
- Moving the evap canister didn't help this problem.
if the fuel pump control module controlled or regulated voltage, why would there be a resistor in the engine bay?
for that matter, follow the above conclusions written above.
why not kill the velocity all the way down to supply the specific volume required at a specific number psig? oh wait, that's going backwards in history.
unless you have denso drawings and designs you'll never know. Toyota doesn't ever break ground on new tech.
I'd have a hard time believing the fuel controller even monitors anything more than one wire from the body ecu.
pcm controlled rpm on the fuel pump. no i don't think so
for that matter, follow the above conclusions written above.
why not kill the velocity all the way down to supply the specific volume required at a specific number psig? oh wait, that's going backwards in history.
unless you have denso drawings and designs you'll never know. Toyota doesn't ever break ground on new tech.
I'd have a hard time believing the fuel controller even monitors anything more than one wire from the body ecu.
pcm controlled rpm on the fuel pump. no i don't think so
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Which resister are you referring too? There's probably several. The one that everyone sees is the Daytime running lights resistor on the passenger side.
As for the ECU controlled fuel pump, it sounds like you are assuming it is a closed system.
Don't believe me? I found you a video...
As for the ECU controlled fuel pump, it sounds like you are assuming it is a closed system.
Don't believe me? I found you a video...
Just because it came that way from the factory doesn't mean it's best. There are so many other considerations that manufacturers have to juggle. Taking a wiring diagram as gospel and disregarding the physics of electricity is probably the wrong way to go about fixing problems.
- Thread starter
- #953
J1000, we've never meet, yet you presume to know me!
Regardless, now your implying not all boil fuel. Just one driven certain ways.
I would agree with this. There are a few things IMHO need correcting.
But if hot wiring (bypass resistor) fuel pump, corrects fuel pump issue we see in 06-07. Then replacing fuel pump, would not correct. But it does, and does long term. It also keeps design as intended. Without any other mods or parts need replacing.
You've not really said why you hot wire FP, or did I miss that. If it's a case, of design flaw resulting in to little voltage. Wouldn't correcting output, be the best way to go!
Hot wiring fuel pump, I don't see as one cure. Sure it can be done, but at what expense. Seems your going down a rabbit hole on it already. In that you replaced the fuel damping device (FDD) with new OEM. Now, adjusting it pop up screw on FDD, which is a factory preset. You're the first I every heard of, need this replaced or adjusted. Is this in the same one you've 12 holes fuel injector. Is that causing some resonation in fuel rails. Or did the FDD, fail (screw not pop up). Is it the same pure ethanol 100s, that you insulated every fuel line. I've know idea which rabbit hole you've gone down!
Hey Dace, good to hear from you.
I agree, for the most part. In "At this point, I believe the main factors for this are:
- These trucks weren't designed for ethanol fuel. So the baseline from which we start is skewed right there.
- Agitating the fuel in the off-road scenario adds to that.
- Moving the evap canister didn't help this problem."
But Toyota does imply, they did engineer for up to E10.
06-07 gas cap:
Dace, I don't recall if I ever mention. A one off issue I had in Butter. It was 7 years ago, when I was driving back from SoCA. Because I love driving 100s cross county. I took, the longer Northern rout back to Denver from SoCA, where I bough it. It was Sept and even driving along the CA/NV desert, it only hit about 90f OAT that day. That even after stopping for Dinner, at the eastern base of ridge to Lake Tahoe. We drove up and over to Lake Tahoe. Near the top of the ridge, I felt a shutter and saw RPM bounced a bit. Next day I check air filter, and found it to be the factory installed still in at 54k miles. It was the dirties I'd even seen.
What's interesting, is PO (I felt sold) do to shutter. Service history at Toyota showed he bought in for a shutter. I was shocked Dealerships, didn't replace the air filter. But perhaps a little more was going, perhaps with tank pressure. IDK. But, I replace air filter while on may way to Salt lake City, a day or two later. The shutter never happen again. It also was very clear, the dirty filter was affecting fuel trims (ECM). As the MPG drop drastically, after installing the new air filter. Perhaps Butter has had an event, where Charcoal Canister has flood, before or after my 3 months I had it.
- "Agitating the fuel in the off-road scenario adds to that."
It seem the idea there, was to leave expansion room. Which trail agitating, result in expansion and increase tank pressure. Adding that, high summer OAT, sun and lower boiling point with increase in altitude. Would be the same as overfilling fuel tank by squeezing pump handle after auto shut off. Even filling fuel tank, stopping at first at first auto pump handle shutoff. Could result in over filling, on a hot day. Since fuel comes out of storage underground storage cooler than OAT and expands with great OAT and road temps in the summer. Also we need to consider, angles. As incline's and tilt, can be much greater off road,. This too, if a full tank, could flood the CC.
Why does over filling matter. Your next point:
- "Moving the evap canister didn't help this problem."
Since I starting, looking at the fuel boiling issue around 2020. It's the Charcoal Canister (CC), I've found to be an issue with most fuel boiling. That is once all upstream issue with coolant system, engine and transmission corrected back to factory spec. Which most 100 series, that come and ask me to look over. Have many upstream issues. Most are running hot (above 200F), and don't know it. The CC being issue that must also be corrected, is much more prevalent in the 03-07.
One 05, was the worst cases I've seen. Even after all upstream issues corrected, which there were many. It was so badly "fuel boiling", even driving around Denver on an 70F OAT day, vapors could be seen and smelt. The smell, started out as bad gas smell. Like gasoline sitting in a gas can for years. Than fresh gasoline mixed in to smell, as engine run for awhile. It then started stalling, while idling at a stop in D. Once CC replaced, problem solved. At least on my test drives, and lack of report to the contrary over the last year. I'll note: It was being fuel to the top, squeeze pump handle repeatedly after auto shut off of pump handle. Until I warned them not to. It was also, used off road fishing & camping. It's CC felt considerable heavier, than new going in. Heaviest I've pulled.
Also consider:
Some venting is normal. In the OM it states, some hissing when remove gas cap is normal. It's why the cap has a check valve, it release pressure once system design pressure exceeded.
03-05 gas cap
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it is this resistor. it is right behind the AHC fluid tank.
from the EWD, the pump is switched between 2 modes. one with resistor in-line and one without.
@2001LC You have multiple clients of yours in this thread complaining that they still have fuel boiling issues after you worked on their trucks. But you continue to pretend it's not a problem on any truck you work on.
I have asked multiple times if you have done those things and you never respond so I presumed that you do not. And I have met you. You have street tires and ruinning boards on your LX. Not offroad worthly.
Of course. Boiling fuel is not something that happens every time you get into the truck. It only happens on really hot days with several hours of driving, minimum. Duh. It would happen to any 100 driven that way, yes. If you don't drive that way, then no. Pretty simple! We are talking about heat build up, which by nature takes time.Regardless, now your implying not all boil fuel. Just one driven certain ways.
This is broken English. Makes no sense.
I did, actually. Again, this is broken English and hard to understand.
Expense is 50 cents in wire and heat shrink. My truck has 300k and has a supercharger so I went the extra mile to baseline the fuel system.
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Hey Paul, I do recall you saying you had to replace the air filter on your trip home. I don't remember anything about a shudder but that was 6(?) years ago now. Butters has never shuddered since I got it from you. The truck has run flawlessly. The couple of times I experienced the boiling, I shut the truck off and let it sit for 30 or so minutes with the hood open and it was fine after that. The first time it was vapor locked and wouldn't start up until cooling. I didn't even try to start the second time until it was cooled.
"Imply". That's seems as far as they were willing to go there. I'm guessing they were trying to meet new standards with existing R&D. It was pretty easy to get away with then since it would be years down the road for problems too accumulate enough to provide some evidence of a problem.
I do tow a lighter camper-trailer a couple of times a year. For those times, I intentionally put non-ethanol fuel in the tank if ambient temp are going to be hot(~mid 80's and up). I don't know if that actually helps but I figure it's cheap insurance/piece of mind.
@sunfic To clarify, the question above... 98-02 has a fuel pump ECU and the 03-07 has the resistor..... neither have both ECU and Resistor. The Fuel pump ECU is located near the factory jack. If it has the ECU, it is has 3 speeds vs 2.
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Yes I understand this. the issue with resistor is that the resistance value will change for different temperatures. at 68F it should be measured about 0.7-0.76 ohms. with higher temperature, the value will be higher which will reduce the voltage on fuel pump. to say fuel pump should get about 10V around 70F but in 90F it only gets 8V which will reduce the fuel flow or reduce the cooling capacity.
However, this is only the analysis for the resistor. for the gasoline or most liquid, the viscosity will be reduced with higher temperature.
also we need to consider the pump performance in different temperature. I believe for different temperature the pump flow rate will change as well.
I think toyota engineer is trying to balance those factors to get more constant flow control. at least the engineer think resistor is a better solution so they changed back to resistor solution in later years LC100s.
The resistance also increases with age.