Throttle opener control valve and servo diaphragm for a 240z?

[Captain Obvious]

Chickenman, Other than some length of vacuum tubing, he's already got all the parts he needs right there already on the car including the ability to screw adjust the amount of idle boost desired. As described in post #11.

 

Captain out.

[Johnny wick]

Chikenman,

 

Thanks for your kind advice. I think Captain Obvious is persuading me to forget about all the Throttle opener control valve and the Servo Diaphgram fastened to the balance tube. Maybe i should just remove those parts leaving the balance tube clean of crap and raise the idle screws on both carburtors to 1100 RPM. Do any of both of those parts have an effect on the car´s driveability for example when decelerating (removing the foot from the acceletor pedal) the car sometimes backfires. I wanted to keep them but if they are non functional, i will remove them right away and get some bronze screws to close the holes.

[Chickenman]

I have a fairly large cam in my 280Z ( Shneider 280 duration ) and I have to run it at 1,000 to 1,100 RPM for idle speed. No issues at all..... until the AC kicks in

 

I have AC as well, and with the low manifold vacuum caused by the big cam the factory vacuum AC kicker doesn't work very well. I've really had to tweak things to get the AC vacuum kicker to work. Even then it's not satisfactory and doesn't work properly all of the time.  I'm going to an electric solenoid on my 280Z to keep the idle steady when the AC kicks in. 

 

On a 280Z though it is easier to retro fit an electric solenoid in place of the factory vacuum pot than on a 240Z. There are already mounting points and brackets on the manifold and the throttle linkage has a " Leg " for the solenoid to press against.

 

The first solution of mine for your 240Z may be a bit too complicated. There are other solutions that may be simpler.

 

Edit: George. I can't remember at this point, ( there's been too many posts ) but don't you have a bigger camshaft in your car. A 274 degree duration one I believe??

 

Ah yes. Found the post where you mentioned you had a Shneider 274 duration cam. That does make a difference to idle quality, How much depends, but my 280Z with a 280 Shneider is rather finicky with the factory AC vacuum kicker. That's why I suggested the electric solenoid.

 

http://www.classiczcars.com/topic/51548-ngk-bp6es-spark-plug-burn-color-ok/#entry470480

Edited December 2, 2015 by Chickenman

[Chickenman]

Chickenman, Other than some length of vacuum tubing, he's already got all the parts he needs right there already on the car including the ability to screw adjust the amount of idle boost desired. As described in post #11.

 

Captain out.

Problem is finding one of those 240Z AC pots. Then you still have to plumb in one of those Ruby Goldberg electric/vacuum combo valves, which can be finicky.

 

The other issue is that George has a bigger camshaft in his car ( Shneider 274 ), and the vacuum servo/pot system doesn't work well with the low manifold vacuum caused with a bigger cam. It all depends on how much manifold vacuum the engine pulls.

 

The bigger camshafts also cause the idle to be pulled down more when the AC kicks in ( if no AC kicker is used ) . How much depends on the engine and camshaft combination.

Edited December 2, 2015 by Chickenman

[Johnny wick]

So with my 274F Schneider Camshaft which is still a Street cam i do need an electrical solenoid! Where do i get one, where do i install it  and how do i fabricate the base is the issue!!