Hey Guys, I was wondering how important the double throttle diaphram is in the idle process, more specifically when the car is already warm. Thanks!

 

None at all.

 

Alrighty, Thanks!

Oh you might want to read my next thread also, its interesting. Also has an interesting title =)

 

On your 86 non turbo, if the double throttle diaphram is busted, then the outer set of throttle plates are spring loaded to full open all day long.

IF the double throttle diaphram actually is working, then the outer set of throttle plates will pull to the full closed position when the engine water is cold. Once it warms up fully, the double throttle diaphram loses it's vacuum source and goes fully open the rest of the day as long as the water is fully hot.

On a turbo car it works similar but different. Once the diaphram loses it's vacuum, the outer set of throttle plates stay closed, unlike the non turbo car, but will open fully as the throttle is opened, if the water is fully warmed up and the diaphram has lost it's vacuum source.

ON the turbo if the water is still cold and vacuum exists at the diaphram, then when the throttle pedal is depressed, the outer set will stay closed. They're being held closed by the vacuum on the diaphram.

 

What if the double throttle (Secondary) doesn't close when the engine is cold?

 

The car will bogg and have poor acceleration until you drive a couple of miles where upon the water temp will then be up over 120 and the car will drive better or act more normal

In other words you need to drive gently til the water warms up. Drive gently and the car will be ok for those first couple of miles.

I've never owned a RX that had a working double throttle diaphram. All were/are busted.

And like they say, you shouldn't be driving a cold engine hard until the engine gets warmed up.