I have a 1982 cc quad carb, it needs a mixture control solenoid.
It only works part time,
what are the symptoms of a failing solenoid ?

What will it hurt if i don't replace it right now ?

What does the solenoid do ?

 

It's the way the ECM adjusts the A/F mix at idle and part throttle. It's just an electro-magnet that pulls a metal piston up and down that moves the primary metering rods and idla air bypass valve. It cycles about 10 times a second and works on a "duty cycle" principle sort of like a fuel injector- "down" time vs. "up" time. The more of that tenth of a second it's down, the leaner the mix. The more of that tenth of a second it's up, the richer the mix.

It's rare for them to have an intermittent failure since the solenoid itself has no moving parts, but I suppose it's possible. Please note there are conditions under which the ECM won't cycle the solenoid- like if it goes outside the adjustment range programmed in the ECM (for instance a persistent over-lean condition that lights the check engine light), at WOT, and if you key it on with the engine not running it'll stop cycling it after about 30 seconds.

If the solenoid goes non-functional the carb will default to full-rich and it won't run very well and, obviously, it'll get horrible gas mileage.

 

Thanks Damon.

Thats close to what i thought it did but i wasn't sure exactly and how it was supposed to act when it was correct.
I had the car on a engine diagnostic machine at a shop and they said it showed lean 44 code and they told me it needed replaced but didn't tell me why , but they did say it wasn't working all the time.

I'm having starting problems and i wondered if this was why.
Please see my other post " starting problem, help " maybe you can help me too.