what's this in the carb?

[Crusted]

I am having major problems getting my carb idle circuit to function. I know it's the carb because when I swap it out with a different one the truck runs fine.

This part is in the air horn above the 1st slow jet. It's in the working carb. Mine doesnt have it and I wonder if it might be the cause of my no idle. the toyota FSM makes no mention of it that I can see.

What I've done so far:
1. Soaked all parts of carb repeatedly in gallon of b-12
2. Blow compressed air through every single port
3. Verified operation of idle solenoid cut-off
4. Verified float level.
5. Verified proper jet placement

What else? this is driving me crazy. Even if I hold the accelerator in to keep it running, the rpm's do a weird dance. Like kick up 500+ rpms for 10 seconds then back down, etc.

THX
Greg
84 FJ60

[D'Animal]

Is the wire hooked up to your idle circuit solenoid and is the current going through it when the key is in the on position?

[Crusted]

Originally Posted by D'Animal

Is the wire hooked up to your idle circuit solenoid and is the current going through it when the key is in the on position?

Yep. I even hard wired to the battery to make sure it was open.

[GLTHFJ60]

Originally Posted by Crusted

I am having major problems getting my carb idle circuit to function. I know it's the carb because when I swap it out with a different one the truck runs fine.

This part is in the air horn above the 1st slow jet. It's in the working carb. Mine doesnt have it and I wonder if it might be the cause of my no idle. the toyota FSM makes no mention of it that I can see.

What I've done so far:
1. Soaked all parts of carb repeatedly in gallon of b-12
2. Blow compressed air through every single port
3. Verified operation of idle solenoid cut-off
4. Verified float level.
5. Verified proper jet placement

What else? this is driving me crazy. Even if I hold the accelerator in to keep it running, the rpm's do a weird dance. Like kick up 500+ rpms for 10 seconds then back down, etc.

THX
Greg
84 FJ60

That component you have pictured is the valve that allows fuel flow into the float bowl. The float pushes on it when there is enough fuel in the float bowl, restricting fuel, and when there is not enough fuel the float drops, allowing that valve to open and refill the float bowl.

In short, you need that part and I have absolutely no clue what your carb would do without it. Without it, it would have no way to regulate the fuel that's being pumped into it by the fuel pump.

Finally, that part has to be in the service manual. That component is something that commonly comes in a rebuild kit.

[Crusted]

Originally Posted by GLTHFJ60

That component you have pictured is the valve that allows fuel flow into the float bowl. The float pushes on it when there is enough fuel in the float bowl, restricting fuel, and when there is not enough fuel the float drops, allowing that valve to open and refill the float bowl.

In short, you need that part and I have absolutely no clue what your carb would do without it. Without it, it would have no way to regulate the fuel that's being pumped into it by the fuel pump.

Finally, that part has to be in the service manual. That component is something that commonly comes in a rebuild kit.

nope. it's not the needle valve.This part screws completely in like a jet and it is right above the slow jet.

[GLTHFJ60]

Haha, sorry. My eyes were a little fuzzy after a long night.

Without having the part in front of me, I believe that it regulates pressure. I have an air horn in the garage somewhere, but I am 99% sure that you need to have that part for the engine to run correctly.

[grant5127]

Originally Posted by Crusted

Yep. I even hard wired to the battery to make sure it was open.

did you hard wire the ground wire also?? if not do so...sounds like your emissions controller is out of whack being your RPMs are dancing around.......

[Crusted]

Originally Posted by grant5127

did you hard wire the ground wire also?? if not do so...sounds like your emissions controller is out of whack being your RPMs are dancing around.......

I know for a fact that the idle cutoff works because I put the same cutoff on a different carb and the truck runs great. No doubt that the problem is inside the carb....

Thanks
Greg