2f Aisin Carb questions.

[honk]

What does "a sort of seize around it" mean?

The rod should extend from the body of the solenoid as it is the operative part which closes or opens the fuel passage. It's possible that someone has deactivated the solenoid's function in order to allow uninterrupted passage of fuel. If done well and with some provision to prevent fuel from being displaced into the solenoid passage it might mean that the solenoid is not playing a part in your difficulties.

I'd always thought of devices like this cutoff solenoid as smog devices applied to limit engine run-on (aka: "dieseling") in American sold vehicles which are required to meet various regulations which in the 1970's were often detrimental to the normal running of an engine. So I was a little surprised to hear that your truck has one as well. Perhaps someone could see no sense in using a troublesome device and so prevented it's interference.

In that case the solenoid would be irrelevant.

 

[Vossie]

What does "a sort of seize around it" mean?

The rod should extend from the body of the solenoid as it is the operative part which closes or opens the fuel passage. It's possible that someone has deactivated the solenoid's function in order to allow uninterrupted passage of fuel. If done well and with some provision to prevent fuel from being displaced into the solenoid passage it might mean that the solenoid is not playing a part in your difficulties.

I'd always thought of devices like this cutoff solenoid as smog devices applied to limit engine run-on (aka: "dieseling") in American sold vehicles which are required to meet various regulations which in the 1970's were often detrimental to the normal running of an engine. So I was a little surprised to hear that your truck has one as well. Perhaps someone could see no sense in using a troublesome device and so prevented it's interference.

In that case the solenoid would be irrelevant.

Sorry, meant a sieve. Ok, there is a metal brass rod sticking out, with an o ring on the end. But that doesn't move when the solinoid fires...

 

[honk]

Doesn't move? I wonder if it's not moving from its extended state or from its retracted state? The movement is very fast and short, hard to see so it's best to have a finger on the rod while energizing and releasing the thing, so you can be certain.

Does it cut off the fuel flow when extended, or when retracted? Someone here must know for sure.

 

[JAFO2014]

The solenoid must be energized to allow fuel to flow. Must have 12V. I think when it is energized it gets retracted, so it is opening the passage on retraction and then when de-energized it closes the passage???, with I guess the rod and O-ring. Heck, must be a way to just plug the hole temporarily and run with out it. It is just there to kill fuel flow when you turn off the ignition.

 

[JAFO2014]

If you are really sure that the idle circuit is clear, it sure seems you have a vacuum leak. How could it run so good being choked?

 

[Pin_Head]

If you screw the idle screw far enough in clockwise, the engine should run on the main nozzle without the choke.

 

[Vossie]

Ok, I've tested the solinoid, again...

So that brass rod you see does not move. How ever, it looks as though there maybe something inside that does move. Very very hard to tell though. Thoughts?

 

[honk]

That's different from the ones I've got now although I remember seeing one like that used in a 'partscar' carb I had.

This shows your type of valve. It has a thin rod within the external brass portion that acts as the valve itself. The small arrows show fuel being turned away when closed and allowed in when open, and there's not much movement between the two.

The diagram shows a passage chart for an Aisan used on a 22r engine but I think it's typical.