FJ40 engine filled up with fuel??

[Nik]

The other day I noticed a rather bad fuel leak on my daughter's 1978 FJ40. She hasn't been started in a few months, so I figured a fuel line busted or something. When we got to looking, it looked like the drip was coming out of the front of the engine thru the timing chain cover. I had it hauled to a shop were they ended up draining 10 quarts of fuel from the oil pan. anyone have a an idea on what would cause this?

 

[Poser]

A bad fuel pump will cause it, every time.

 

[65swb45]

Depending on how old your seals are, and how long the fuel has been in there, you might have to change the seals as well.

 

[Mace]

I had this exact thing happen. Mine was because I had removed every piece of smog equipment from the fuel system and sealed the tank. A full gas tank, vegas heat made the fuel expand and bypass the spring loaded needle and seat in the carb. Filled the oil pan nicely.

Although, Mine was leaking gas out of the rear main seal. Not the timing seal..

BTW, If it was through the carb, lube the crap out of your cylinders before you start it. I heat seized my 6 when I tried to start it after washing the rings out.

 

[RWBeringer4x4]

I'm not sure if FJ40 carburetors are prone to this, but this was happening to my 40 as well (running a 283 SBC and Quadrajet). The Quadrajet has welch plugs that had failed, and was leaking gasoline down through the manifold as it sat. If the 40 carbs can leak in this way as well, that might be another place to check. I'd start with the fuel pump though, as Poser said. That is probably the most common - and an easy fix! Hope the gas hasn't washed your seals...

 

[Sam Stewart]

A bad fuel pump will cause it, every time.

That's what I was thinking. Fuel pump just dumping fuel into the engine.

 

[JohnVee]

How timely. I just had the same problem in my 350/Holley. I rebuilt and installed the carb. Didn't get the floats set right and let it sit for 2 weeks. Drained over 5 gallons of gas/oil mix from the pan when I got back to it. I've got an electric fuel pump but the battery was removed that entire time so I can't blame the pump. I've since corrected the floats and I'll blame the desmogged system and the warm weather for building enough tank pressure to cause this. I'm hoping to get out this weekend and take care of it. Really hoping all seals are still gonna be good.

As ROXX told me, "The good news is your engine is clean. The bad news is your engine is clean".

--john

 

[Nik]

So what is the best way to lube the cylinders before starting it? Just refill it with oil and manually turn the engine over?

 

[Alstruck]

I'm a new owner of a 71 FJ40.
Isn't the fuel tank vented so when the fuel heats up the pressure vents out and doesn't pressurize the fuel system?
I've heard of a bad fuel pump diaphragm breaking and fuel getting into the engine. Usually the fuel tank is lower than the fuel pump so this won't happen if the engine is not running.
Seems strange to hear these issues are common.

 

[want2wheel]

If they cylinders have been wiped clean with excess gasoline the bearings are also dry. I would put some oil on top of the cylinders, and use a drill to prime the engine before I tried to spin it by hand. After priming the engine I would turn it by hand and then try to crank it. After you crank it check the oil for gas smell. If it smells of gasoline I would chane it again.

 

[Howard705]

Was fuel pump on mine. DRAIN OIL and refill before starting it up. Gasoline doesn't lube bearings. Replaced V8s in the past for running this way.