Gas/Fuel vapors/fumes visible from gas door

[isthatalexus]

I think going back to the OEM fuel tank skid helped a little but I still got some fuel smell if not actual gurgle gurgle boiling and puking. Went ahead and had the skid drilled out around the cats. Hoping this helps to get more air flowing and reduce what I think is an oven that had been created. Not ideal, but I'm experimenting at this point.

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Possibly SQOD: if one were to wrap the cats + about 6" in either direction with some kind of heat shield, would the cats have a problem given the absence of air cooling?

Also, I ran with all skids off for a while, and I'm not sure it made a huge difference. My issues resolved after new CC and thorough radiator cleaning.

 

[bloc]

Possibly SQOD: if one were to wrap the cats + about 6" in either direction with some kind of heat shield, would the cats have a problem given the absence of air cooling?

Toyota didn’t design them to run like that so we can’t know what the effect would be on their lifespan.. personally I wouldn’t risk it for such an expensive part.

That said, heat shielding over other objects in the area to cut down on radiant heat would help a lot. Teckis has posted about this.

 

[TheGrrrrr]

I think going back to the OEM fuel tank skid helped a little but I still got some fuel smell if not actual gurgle gurgle boiling and puking. Went ahead and had the skid drilled out around the cats. Hoping this helps to get more air flowing and reduce what I think is an oven that had been created. Not ideal, but I'm experimenting at this point.

View attachment 3663496

Just back from a trip to Mexico, where i had boiling fuel from when I left Phoenix in 106f heat (the truck was idling for close to an hour in the driveway while I packed it) all the way to Ajo, AZ where we had to let the tank cool in order to fill up. From there to Puerto Penasco, no issues. Coming home no issues in Puerto Penasco until we hit Gila Bend where temps reached 104f. Fuel smell started between Gila Bend and I-10 and got worse as I got closer to Scottsdale in the 106f. Venting the skids seems to have achieved nothing at all. Maybe they didn't get vented enough. Pretty frustrated at this point. There just isn't any way a truck designed to function in the harshest environments should have this problem. I'm not convinced going back to the factory skids will completely solve the problem, either.

I think I'm jumping directly to this solution. Nobody has been able to determine if the heating of the return fuel is happening in the engine bay or running past the cats or both, and if people have had the issue with bone stock trucks then it must be at least somewhat tied to engine bay temps. In either case I would think mounting this in the spare tire area and wiring it to have the fan run at all times the engine is running would be the most effective solution. Do you think it would cool enough to make a difference?

Amazon.com

 

[nwfl4runner]

I’m in the same boat, I just don’t know where to tie into the return line in a way that could be reversible - Toyota uses plastic metric quick disconnects that I couldn’t locate elsewhere

 

[grinchy]

One could get the fuel hose interface/pump bucket assembly and tap in 'behind' the stock interface (on what is meant to be the internal side of the tank), put the cooler behind. Here's what the front and back side look like.

 

[grinchy]

Or even better, maybe just buy an return hose and modify that . . . hmm.

 

[TheGrrrrr]

Or even better, maybe just buy an return hose and modify that . . . hmm.

The part I don't know is what size line/cooler fitting size should I be buying? The one I linked the right size?

 

[nwfl4runner]

Or even better, maybe just buy an return hose and modify that . . . hmm.

I did just that, the return hose is metric and connects to the tank through a plastic quick connect piece - I’ll send pictures tonight of what I have

 

[grinchy]

I was thinking this part number

77204-60060, which is labeled fuel return hose. I don't recall from the sub tank install if it was metal or plastic unfortunately, probably metal with a plastic/rubber interface at the pump top cap.​

 

[linuxgod]

Matt I have to admit you definitely have more boiling issues than I’d expect with a non-aux tank setup.

I think my only issue with this idea is the durability of the fan. The radiator cooling fan lasts a long time, but every computer fan I’ve owned dies after a few years. Don’t really depends on the quality and how well it’s sealed from the elements

Outside of that, how do you get enough airflow through it while protecting it from rock strikes and such? Overall it seems like a solid idea

 

[TheGrrrrr]

Matt I have to admit you definitely have more boiling issues than I’d expect with a non-aux tank setup.

I think my only issue with this idea is the durability of the fan. The radiator cooling fan lasts a long time, but every computer fan I’ve owned dies after a few years. Don’t really depends on the quality and how well it’s sealed from the elements

Outside of that, how do you get enough airflow through it while protecting it from rock strikes and such? Overall it seems like a solid idea

At $200 if the fan dies, its still a radiator and should serve some function, but can be replaced entirely or maybe the fan can be replaced. I do think the spare tire area is a decent candidate for location to keep it nice and high. I could probably fashion a guard of some kind out of thin metal to shield it from pebbles and stones.

 

[bloc]

I'd be worried about a finned-core heat exchanger under the vehicle clogging up with dirt and junk. Plus yes the fan issue.

 

[TheGrrrrr]

Substantial and well built. Aluminum mounting frame should provide protection from flying rocks/debris. Fan shroud and grate are much more robust than expected. Impressive at first look. Dimensions in inches are roughly 13x9x4.

 

[TheGrrrrr]

Matt I have to admit you definitely have more boiling issues than I’d expect with a non-aux tank setup.

You are right. I just shot some photos from underneath in my driveway and really took a good look. I wouldn't know if something wasn't right, but I did notice some zip ties in places I haven't touched during my ownership. To my knowledge the only work done on the fuel system is replacement of the charcoal canister. Thoughts on anything in the photos looking wrong to you? I think this truck got hit in the rear quarter and an unreported repair was done. That would account for the paint failure around the filler where the gas ate through the low quality paint. Need to have it gone through and returned to factory spec. Surprised and disappointed that nobody who has worked on this truck (including me) noticed any of this.

 

[TheGrrrrr]

I was thinking this part number

77204-60060, which is labeled fuel return hose. I don't recall from the sub tank install if it was metal or plastic unfortunately, probably metal with a plastic/rubber interface at the pump top cap.​

View attachment 3668979

According to Partsouq this is the photo of 77204-60070 that is the only part I could find that fits your description:

If we we're to want to shield heat from the engine bay, it looks like this is the part we would need to wrap with heat shield... if we think the fuel is picking up heat from the air:

23902-38011 - return line that connects to 77255-60B10

return line that connects to 77255-60B10:

Which connects to our guy at the top: 77204-60070:

Now do we believe shielding these three parts from heat will solve the problem or do we believe we need to add a cooler to the last part on the return nearest the tank?

 

[linuxgod]

You are right. I just shot some photos from underneath in my driveway and really took a good look. I wouldn't know if something wasn't right, but I did notice some zip ties in places I haven't touched during my ownership. To my knowledge the only work done on the fuel system is replacement of the charcoal canister. Thoughts on anything in the photos looking wrong to you? I think this truck got hit in the rear quarter and an unreported repair was done. That would account for the paint failure around the filler where the gas ate through the low quality paint. Need to have it gone through and returned to factory spec. Surprised and disappointed that nobody who has worked on this truck (including me) noticed any of this.

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I can try to take some photos for comparison this week if it’ll help you, though the underside of my truck has a muddy Moab coat on everything still.

I wonder if there’s a hard line that’s kinked or something building additional pressure in the vapor return. I’ll try to look closely at the FSM to see how it’s all plumbed. I really don’t know the fuel system that well, only that I’ve driven through 100F+ temps while towing and never had fell boil so I’m still sure your issues are not normal.

 

[bloc]

The rails must be a large source of heat…

 

[grinchy]

According to Partsouq this is the photo of 77204-60070 that is the only part I could find that fits your description:

View attachment 3671417


If we we're to want to shield heat from the engine bay, it looks like this is the part we would need to wrap with heat shield... if we think the fuel is picking up heat from the air:

23902-38011 - return line that connects to 77255-60B10


View attachment 3671503

return line that connects to 77255-60B10:

View attachment 3671507

Which connects to our guy at the top: 77204-60070:

View attachment 3671509

Now do we believe shielding these three parts from heat will solve the problem or do we believe we need to add a cooler to the last part on the return nearest the tank?

I don’t think this hose to the fuel pump is a heat source, I do think it might be a good place to put the cooler in line. Specifically if you can remove the plastic connector and put the cooler out/in at that location or using that fitting. Or the fitting location at the other end of the return, whichever is easier to get to.

 

[TheGrrrrr]

I ordered all 3 segments of new return lines as well as a new Charcoal Canister Filter Sub-Assembly (77255-60B10) as that doesn't appear to have been replaced with the Charcoal Canister.

I'll wrap all three segments of return line with heat shield so in theory the only heat getting into the fuel is from the rail and not from its ride back to the tank. Once thats done and the filter is replaced, I'll drive it to Flagstaff on a 110f day and see if its any better.

If not better, then we can assume the buildup of heat in the tank is a combination of heated fuel strictly from the rail and ambient/radiant heat from air/roads heating the tank itself.

Then we can install the cooler on the last segment of the return to further reduce the rail as a heat source.

 

[FerrisBueller]

I can definitely fit the reservoir, pump, and fuel cooler here in the engine bay, and it's conveniently right next to the battery and the last section of return fuel hose that wraps around back of the engine before it connects to the hard line, which is a good tie-in point. Then I would then route coolant lines up front to a small radiator that I already confirmed will fit behind the grill, giving it the coolest air possible.

Unfortunately, it means if I want onboard air at some point, then it can't go here. But that's okay.