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Builds Saved from scrap - '97 LX450 build thread (4 Viewers)
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Yeah its nice there. Lots of dispersed camping. We're only about 1.5 hours away so usually not too much of an issue to go. This weekend I had to repair the black water tank on my 5th wheel though
- Thread starter
- #603
Fuel cooler bracket finally back from fabrication. Looking forward to confirming it actually fits!
FMC80
SILVER Star
Matt, help me understand why you would want to cool fuel? I have always worked under the assumption we want to cool oil and heat fuel for better lubrication and combustion, respectively.
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- #605
Because boiling fuel in my tank, as much as it's super cool and exciting, isn't for me. Also turns out the truck doesn't run well on bubbles.
FMC80
SILVER Star
Ah. Your fuel is boiling. I wish my fuel was boiling right now; it must be nice having a running engine.
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- #607
I haven't turned the key on mine for a month. Work has beenAh. Your fuel is boiling. I wish my fuel was boiling right now; it must be nice having a running engine.
Where's the heat coming from? Pump? Line routing?
- Thread starter
- #609
Good question - Original thought was the lines on the inside of the frame rail picking up heat from the left exhaust bank and recirculating back to the tank. Lines were moved to the rocker panel, but problem persisted. Current wisdom is at slow speed for long durations (>8hrs of solid wheeling) heat from the left exhaust bank is blowing back over the tank and slowly heating the entire tank. Secondary gain may be from the return line running up to the fuel filter in the engine bay and back to the tank - the back pocket of the engine bay where the fuel filter sits was pushing 160F at slow wheeling speed, which was the reason for the louvers, etc.
No matter the cause, the cooler should solve the problem. It's certainly not an instant type problem - very much heat soak. The fan will be switched and only used at slow speeds. Also putting temp and line pressure gauges in to help better monitor the situation.
Definitely a weird problem. I've read about some high performance diesels needing fuel coolers. Seems like a rare problem with gas.
FMC80
SILVER Star
200s boil fuel in those conditions you describe.
- Thread starter
- #611
Probably shouldn't discount the fact I drive my 80 like it's an Ultra4 truck.
Maybe I should source and save a replacement frame now
MrMikeyG
SILVER Star
That's an interesting problem. You're going to start folks on a trend of monitoring under truck temps now. The words boiling and gasoline definitely seem like words that should stay far apart though.
And or a front axle housingProbably shouldn't discount the fact I drive my 80 like it's an Ultra4 truck.
Maybe I should source and save a replacement frame now
I've noticed that. One person has an issue and suddenly everyone has to check for a problem they've never even heard of.
I had the same issue (boiling fuel). I originally used the the stock feed and return, and had the filter/regulator on the fuel rail at the intake.
I had to do a new fuel pump as "vapor locking" a FI motor isn't good on the pump.
I put a new filter/regulator on the rocker about where the driver seat is. Shortened up the return line a lot, and fished the fuel line up through the fender than to the fuel rail.
No problems since. I used rubber lines as well.
the new pump gets loud from time to time when it's really hot out, but no more issues w/ boiling fuel.
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Add 'boiling fuel' to your 80 series diagnostic dice across from head gasket and fusible link.
How is the fuel system laid out for the car your power train was designed for (similar to)? Also would wrapping the fuel lines in a heat sheath do anything to lower temps?
- Thread starter
- #617
Thought about moving the the filter/ regulator under the truck and add a passive cooler to the return line, but I wasn't 100% sure that would fix the problem since I think the system is picking up heat from multiple sources. I figure with forced cooling I can leave the filter/ regulator where it's a lot more accessible and pull the heat out of the system with the plate cooler and a fan. After all, it's just money, right?
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- Thread starter
- #618
Any heat getting picked up can only make it back to the tank from the regulator through the return line. I actually don't seem to have a vapor locking problem - My fuel pump shuts off when the tank reaches a certain temperature. If I add a can of cool fuel off my bumper, the fuel pump instantly kicks back in and I'm good to go until the fuel heat soaks and starts boiling again.
- Thread starter
- #619
Since I never shared the comedy gold pictures of the first time I had this challenge when I was on the WABDR:
I drove 4 of 6 sections of the BRD with my hood open in an effort to reduce overall engine bay temps and let more air down the transmission tunnel. Actually worked pretty well. It's why I decided on hood louvers as a permanent fix.
A Wavian fuel can fits perfectly in a bus tub full of ice. Figured cooling the fuel ass much as possible before adding would reduce the overall temp in the tank and extend the time I had before the next shutdown. Had some interesting looks doing this on the side of the road.
@Pascoscout Thanks for putting up with me on the trip! It was exciting, but frequently for the wrong reasons.
I drove 4 of 6 sections of the BRD with my hood open in an effort to reduce overall engine bay temps and let more air down the transmission tunnel. Actually worked pretty well. It's why I decided on hood louvers as a permanent fix.
A Wavian fuel can fits perfectly in a bus tub full of ice. Figured cooling the fuel ass much as possible before adding would reduce the overall temp in the tank and extend the time I had before the next shutdown. Had some interesting looks doing this on the side of the road.
@Pascoscout Thanks for putting up with me on the trip! It was exciting, but frequently for the wrong reasons.
thatcabledude
GOLD Star
The only time I have had this happen is shooting across Texas/Arkansas in August running 80-85mph for the entire day.
I didn’t notice the issue was even occurring until I got off the interstate to refuel. Was running kinda funny and I could hear it bubbling when I shut the truck off.
My lines are AN from tank to rail (along the stock route) with a canister style fuel filter under driver seat area.
