Will a fuel pump cure my vapor lock woes?

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I have a 78 FJ40 that has a 2f engine that has been recently restored. The last few months it seemed to run warmer than usual and if I stopped my car and tried to start it back up, it would just die and not start up until the engine got cool again after 30-90 minutes. It is vapor lock in my gas lines. My local mechanic says a electric fuel pump would be the best solution. I have owned my truck for 8 years and never had an issue til now. What do you guys think I should do?
 
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Maybe I'm wrong, but in my experience (for whatever that's worth) vapor lock exists after opening the fuel system for whatever reason, and once the air has been expelled and fuel reaches the carburetor, it's good to go. I've never seen one that will run for a while, then not start again, due to vapor lock. However, there's a lot I haven't seen. Maybe it's a thing?
 

micruz60

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Retrofit a carb cooling fan ? Also verify the fuel line from stock fuel pump to carb is not being heated by contact to the engine block / head.
Can you post a photo of your engine bay showing the fuel line routing?
 
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It could be ignition related. I don't have a 40 but I do have an old Flathead Ford and they have a lot of problems blamed on vapor lock. It does happen, especially with modern fuel with alcohol. But many times it's actually a coil that fails when hot which has happened to me. Or a failed condenser if you're running points.

An electric pump does help IF you really do have vapor lock.

Like mentioned, find out why it is running hotter than normal.

To add, If it won't start after getting hot, look and see if the accelerator pump squirts fuel. If you have fuel to the carb and it still wont start, check for spark. This will narrow down your failure to start.

Vapor lock is the fuel boiling in the fuel line or fuel bowl essentially leaving you out of gas or the mechanical pump cant pump vapor. Non ethanol gas helps if you can get it.
 
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Toyota put the carb cooling fans on for a reason. It made all the difference in the world when I got mine working.
 

ToyotaMatt

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I have a 78 FJ40 that has a 2f engine that has been recently restored. The last few months it seemed to run warmer than usual and if I stopped my car and tried to start it back up, it would just die and not start up until the engine got cool again after 30-90 minutes. It is vapor lock in my gas lines. My local mechanic says a electric fuel pump would be the best solution. I have owned my truck for 8 years and never had an issue til now. What do you guys think I should do?


this is a simple to confirm and verify topic :

during restore re-asembly , your various FUEL vapor lines are mixed up


2nd
'
you forgot to install the fuel line check valve or installed it back wards



- OEM TOYOTA Fuel Systerm Gas Tank Check Valve Line Hose Petrol Vapor Recovery 90917 Fits Just about ALL Land Cruisers See application chart first please ... - VintageTEqParts.com - https://vintageteqparts.com/products/oem-toyota-fuel-systerm-gas-tank-check-valve-line-hose-petrol?_pos=1&_sid=50710e253&_ss=r



1668758127919.png

1668758141960.png
 

ToyotaMatt

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I have a 78 FJ40 that has a 2f engine that has been recently restored. The last few months it seemed to run warmer than usual and if I stopped my car and tried to start it back up, it would just die and not start up until the engine got cool again after 30-90 minutes. It is vapor lock in my gas lines. My local mechanic says a electric fuel pump would be the best solution. I have owned my truck for 8 years and never had an issue til now. What do you guys think I should do?


i am NOT sure about the fuel pump replacement topic ?


nut if it was sucking air maybe ?


if you need a complete KIT form install approach ?





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1668758307086.png
 

lcwizard

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I have a 78 FJ40 that has a 2f engine that has been recently restored. The last few months it seemed to run warmer than usual and if I stopped my car and tried to start it back up, it would just die and not start up until the engine got cool again after 30-90 minutes. It is vapor lock in my gas lines. My local mechanic says a electric fuel pump would be the best solution. I have owned my truck for 8 years and never had an issue til now. What do you guys think I should do?
I've had this issue on three different 60s in Az summers
get an good electric fuel pump and an adjustable pressure regulator with a return. Place the regulator on the firewall, as close to the carb as convenient to make the run
to the carb as short as possible. The electric should push more gallons per hour than you need so most of the gas will return to the tank and re-cool.
You'll find that , with this set up, the return line will feel as cool as the ambient temps while running. I never had one not work with this mod.
Getting the feed line away from the block and exhaust manifold makes a difference
 
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caveat, my 40 has a 350 sbc in it. Engine ran hot, but never vapor lock in Illinois. This past summer in Montana, did it to me several times. Fixed the hot engine with a bigger fan, also will run next summer a less than 50/50 antifreeze mix. For the vapor lock I installed insulation around the fuel lines. So far so good. If the problem persists, also will do this....... have the part, just too lazy to put in if i don't have to.
 
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Not sure if this is the same issue. Mine would not run hot on engine temp, but after pushing the engine hard for a bit, would not want to idle, some times die and would not re-start until it cooled down a bit. I did a vacuum test and it was low. On advice from a mechanic mud member, I adjusted the valves, this got the vacuum back and my problems went away. May want to check vacuum and valves.
 

middlecalf

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You’re nearly at 8k ft ASL in Ouray. Make sure altitude is accounted for in your carb settings.
 

JohnnyC

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i tend to be thinking in the same line as @middlecalf .... you may be having issues with the carb... maybe overly rich? and its loading up and fouling the plugs

the getting hot may be also the cooling system still has air.... compounding the issue
 
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One thing to consider is the fuel in Colorado has a higher amount of Ethanol. It boils at a much lower temp than pure Gasoline. I always fill my tank with pure fuel up there when I travel at altitude. The cost offsets the hastle of vaporlock issues most times.
 

micruz60

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Adjust the timing for the altitude. Many different factors at play here- frustrating.
 
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a 78 has the return right at the carb,
is there gas in your sight glass?
 
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Hi, When was your last valve job?Smog still hooked up ? Does it work correctly?
 
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Hi, When was your last valve job?Smog still hooked up ? Does it work correctly?
I had an engine restoration done by Profitt's LCs in 2019. Yes, the smog is still hooked up, although not sure it works correctly. The engine has the heat shield under the carb. This issue just cropped up. It's mostly in the garage as I daily drive an 83 FJ60.
 

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