Hello lovely clever people pretty straight forward, althought anything involving cars is never as straight forward as you would hope.

Have a RX8 engine in my FC running of a M2R Motech, was doing a routine little service & noticed this bit of tubing that connects two plastic noozles together ....

http://www.facebook.com/photo.php?pi...8&id=573981001
(sorry about the rubbish link, photobucket isn't working at the mo)

.... anyway the right hand side drops down into the throttle body & the one on the left goes to a small sensor of some sort (which is no longer connected to the loom as obviously it is no longer running of stock management) anyway took it of & wen for a spin with it of, its sucks in a fair amount of air like you would expect but the engine runs a better with it of & when the revs drop done to idle its solid where as before it would drop past idle nearly stall & then level out. Anyone know exactly what is meant for & what effect leaving it off mya have many thanks James?

 

That is the evap purge solenoid port. It is used to suck fumes from the gas tank into the intake to be burned.
You created a vacuum leak by unplugging it.

 

Thanks for the reply, when you say the "gas tank" do you mean fuel tank?

So will it be better to leave this capped as the solenoid it is connected to is no longer in use as it is just free to breathe at the moment, it continously sucks in air but when capped drops the idle down by a good 300rpm!?! Thanks

 

Yes. Sorry. That's an American thing.

It should be capped. You are causing a lean condition otherwise.
You should address this lean condition and idle with proper tuning.

 

Ha that's ok thought that was what you meant, it is an american forum after all

Ok, thats great to know i'll cap it tomor morning & just up the idle back to normal, thanks for your help.

 

Lol