Today at Atelier Kaz - ex-Honda R&D, F1, Indy/CART engineer

The owner mentioned that the idle rpm was stable but not quite.


I’ll be cleaning the TH butterfly for the owner this time.


Removed the air box for the preparation.



As mentioned to the owner previously, looks like our small friend visited this area in the past and enjoyed chewing the rubber bits.


No damage to the wire so good news.


I have seen this on many UK based NSX even on the ones kept in nice garage.


I think I wrote in one of my post in the past that one S2000 owner had to pay 1,000s for the wiring damage caused by the same reason.


On one NSX, the little friend nested inside the air box using the material of air filter to build nice cosy nest.



Looks like someone tampered the idle adjust screw in the past.


This is non-DBW model so it still has EACV, idle air port, dash-pot and so on.


Needs to know exactly how and where to aim the cleaning agent compared to the process on DBW model.


On this NSX, the TH butterfly was little sticky.


The intake chamber was also covered in sticky oil mist.





From time to time, DBW model requires re-adjusting of idle rpm using the specific method after cleaning the TH butterfly.


Again, this NSX is non-DBW so normally, no need to tocuh the idle adjust screw.


Will clean the TH system once the Left drive shaft service has finished.


There was little too much play in the TH cable.


I don't like the idea of reducing the play beyond the spec so will be adjusted within the spec.


I hope the small issue with the idle rpm is nothing to do with the TB service carried out in the past.


In Japan, there were several NSX with TB alignment being off by one tooth especially at the rear bank exhaust side….


Can be checked with the vacuum gauge or simply open the valve cover.

Kaz