Nissan Repair: nissan diaphragm secondary throttle valve, nissan sentra, vacuum diagram

Question
Hi,

I Have a '98 Nissan Sentra B13 16 valve.

I want for my secondary throttle valve to open directly wen I Throttle the engine. Do you know which vacuum works with the throttle. (when I throttle it vacuum and when i do not throttle it does noting.)

Thank you,

Maikel

Answer
Maikel,

You could do it by applying vacuum directly to the port that controls the secondary throttle valve.  This is the large diaphram that controls the secondary throttle.  Look at your vacuum diagram under the hood for the port.  I would not do it since it will really hurt you off idle response since the engine will be getting way too much air to the second set of intake valves.  Way too much volume of air to use at just off idle.  Your choice here.  Let me know how it goes.  You would never see the secondary air tract open when the car is sitting and you open the throttle.  It is at a much higher RPM when it kicks in and reving the engine that high when your not driving would be bad for the engine.  You could check the function of the valve by just applying straight vacuum to the valve, at idle.  Remember that the vacuum you want to hook the diaphram up to use, if you are going to do this, is ported vacuum.