Too Much Fuel: BAD fuel smell; With Pictures! Gas in Intake Manifold (1 Viewer)

jbee

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I hate to complain about a good running and driving truck but. . .
1972 FJ40. Original engine (good compression), 3spd trans, newer plugs, wires, etc. Stock correct 4/72 carb rebuilt within last 100 miles by the shop that does all the rebuilds for local toyota dealership.
Running a mid-80s 60 series electronic distributor, dented side cover style (Per @Coolerman ) and the extra hold drilled in the carb.
Asked Jim C if I need a recurve on the dizzy and he said 'nope.'

I reviewed the '2f intake manifold leak' thread but not sure if it's the same and did not want to hijack that thread if not. (My idle solenoid is wired to the voltage regulator, I think, below the brake booster)

Truck starts (with a tiny bit of choke) runs/idles just fine (choke off). Runs smoothly, not like a misfire at all.
Accelerates as well as a 1f can, top speed of around 60, a little drag at the top end.
While running, it smells like raw fuel BAD. Replaced exhaust recently (needed it badly) and that made it more quiet and less exhaust in the cab but still strong fuel smell.
Black smoke and raw fuel out the exhaust too.
Does not get driven much, but when I get it out of the garage I drive it a lot for a week or so; still bad fuel smell.

Removed the (stock) air cleaner for a look-see.
Raw gas soaking the front passenger side of the carb base. Turns out that stud is stripped so cannot be tightened. When I removed carb to repair manifold I found fuel everywhere and an impressive puddle in the bottom of the intake manifold (at least it's not cracked. . . ) Gaskets soaked, carb base plate soaked. Looks like site glass was empty.
Photos below. Sorry for the long intro, want to provide all variables.
Just the loose stud? Internal carb problem?

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ToyotaMatt

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Its time to get Serious about all that dangerous fire hazard Jazz............🤔


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Its hard to tell in a photo, but just eyeballing, that doesn't look like a metric stud. Its definitely not OEM hardware as the stock studs are partially threaded on each end. You can repair the stripped threads with a time sert kit. I would think an air leak at the carb base would create a lean running condition. The AFR would tip heavy on the air side.

I would make the stud repair, use new gaskets and see where you're at. If you have multiple issues you need to approach this systematically. Start with the obvious, report back and we can work through the technical stuff.

As @ToyotaMatt suggested, a carb rebuild is probably in order. Regardless of who rebuilt it, you cant trust anyone these days.
 

jbee

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Thanks for your input!
Ordered a rebuild kit.
As you can tell that carb stud actually is threaded on both ends with a dead spot in the middle, like the factory ones. There is a different thread pitch at each end.
Manifold gave out in that spot, prolly from too many carb changes!!
I bought the thread repair kit, will install tonight hopefully.

The truck runs like a top, starts on a half turn of the starter, will often idle from cold with no choke. I think a major vacuum leak or lean condition would cause it to run poorly?
I get no backfiring at all, even if I lift under heavy acceleration: pulled plugs and they look good. Expected them to be wet and gassy but they were not, also not all dried out like clean condition. (See photo)
Compression 150,150,150,150,120,120.
I’m thinking extended periods of sitting caused something inside the carb to fail.
Regardless I will have the carb rebuilt with a new kit and new base plate gaskets, I have a vacuum gauge will check for vacuum leaks as well.

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