What Is The Solenoid Between Throttle And Plenum?

[YangLIU]

hi fellows,

i got randomly rough idle with grey/black smoke when idle in auto "D", nearly stall, maybe will stall later. driving is ok. when open bonnet, i found the plug is disconnect from solenoid between throttle and plenum. what's that for? does it cause the problem when idle?

thanks.

Edited May 8, 2016 by YangLIU

[scotty nm35]

It sucks vapours from the fuel tank, through the carbon cannister.

[YangLIU]

It sucks vapours from the fuel tank, through the carbon cannister.

Will it cause idle problem if disconnect the solenoid?

[scotty nm35]

No idea, why would you leave it unplugged? At a guess it could, as the solenoid is likely open at idle.

[YangLIU]

No idea, why would you leave it unplugged? At a guess it could, as the solenoid is likely open at idle.

ah...forgot to connect it back when do some mod....

btw, i mean the power plug is disconnect, so i assume there is no air leak causing rough idle problem even though the solenoid does not have power.

Edited May 9, 2016 by YangLIU

[sleeper_gtr]

Looks like the aac to control ya auxiliary air control. Makes sense as I've heard it might give you a rough idle. Please confirm ppls

[Ben C34]

^

It sucks vapours from the fuel tank, through the carbon cannister.

[YangLIU]

Looks like the aac to control ya auxiliary air control. Makes sense as I've heard it might give you a rough idle. Please confirm ppls

i re-connected the power plug for that aac, so far no rough idle. but there was only randomly rough idle before, so i can't make sure if rough idle really get sorted.

Edited May 12, 2016 by YangLIU

[scotty nm35]

It's not aac, iac or any other idle valve, it is a purge solenoid for the fuel tank. As you are stuffing around with the amount of air getting into the plenum it may help anyway, but I wouldn't touch it.