Carb Issues - No Start (1 Viewer)

[Perovich]

I'm curious if someone could steer me in the right direction. I was getting ready for a knuckle rebuild and needed to move the truck into the garage to work on it, but it died on me at the other end of the yard.

The engine (still a 2F) has around 600 miles on the rebuild. Everything has been broken in and fine-tuned.
The carb is the Trollhole FJ60 carb with fewer vacuum ports. Virtually all the peripheral parts are new.

Since the installation, things have gone mostly smoothly, but have progressively gotten worse. Occasionally, the truck will randomly have a no-start condition. This first happened on the first run with the new carb.

Sprayed some Carb cleaner into the carb throat and it kicked right over, ran perfect for a few hundred miles after that. That doesn't seem to work any more.

Now it started, then died about 20 seconds after initial fire-up. I took the fuel line off the inlet of the carb, and I'm getting good pressure (new fuel pump) and volume. Each cylinder is between 155-160 PSI. Spark plugs look brand new, contacts on the cap and rotor are good.. I'm getting spark off the coil, from the cap, and to each wire. The ignition and compression side of things look fine.

So what am I missing? The fuel level window appears empty (or full?), I'm getting fuel to the carb, but not even a hint of wanting to fire up. Needle stuck? A local cruiserhead said something about the aftermarket carbs using composite floats that get saturated with fuel?

I'm a new-school guy, so color me confused. Any and all advice is appreciated.

 

[gregnash]

So if you pull the choke will the engine continue to run? Seems like you have done your homework but with all the the one thing that is left out is the ICS which controls your idle. If the truck will run with the choke pulled then your ICS (or something connected) is to blame.

Also, with the fuel, the bowl should be halfway full. You should see the line across the sight glass so if you are not seeing any in there then the truck is going into a starvation mode with no fuel. If it is full to the top then the float is messed up and you are probably completely flooding the carb.

 

[Perovich]

I don't think it'd continue to run. I can't fire it up so I don't know for sure; I've done the green wire mod thinking it may be a shoddy connection, no dice.

I'm leaning towards float at this point. Been around an hour and either my fuel bowl is 100% full or 100% empty

 

[OSS]

Shake the truck from the driver's side fender when engine is off. You should see fuel sloshing in the carb sight glass. Never above the sight glass.

 

[Perovich]

That was my thought too. But no discernible amount of fuel anywhere in the sight glass; it seems either flooded in that the fuel is above the sight glass (if that's possible... I'm leaning toward no) or 100% dry.

Just got back from the wrecking yard, so I'll get back to diagnosing, maybe see if I can't slap a stock carb on there and get it to go.

 

[gregnash]

Yeah time to pull the horn and see what is going on. That will tell you right away if fuel bowl is dry or not.

 

[Perovich]

Just updating - fuel bowl ended up being dry. The seam where the float was cast seemed off and there was a pinhole on the corner. Also upon further inspection, the cup on the accelerator pump had a sizable tear in it. Checked the side of the channel and sure enough there was a jagged edge in the casting that seems to have cut into it. The lever going to the pump was also off-kilter by quite a bit - it seems the carb was either dropped at one point or the retaining bolt wasn't threaded in entirely.

I don't know how I didn't notice that on installation

I tried hooking the original 2-wire ICS up to 12v and ground and didn't hear anything indicating that it was working, so I transfered the 1-wire to the "old" carb and will see if I can't get it going.

I'm so used to fuel injection, that this has been a surprisingly fun learning experience. Thank God for having two vehicles, thanks fellas!