AEM EMS Series 2 - having challenges dropping my idle

[BATMANs]

Ever since I had this installed my tuner hasn't been able to drop the idle from 1200~ RPMS to below 1k RPMs (ideally 750RPMs).

This is important for me to pass the idle portion of the smog test.

Any ideas?

 

[Blacknot]

Sounds like a vacuum leak

 

[DDozier]

What year? CTSC?

If it is a non-tbw car and a CTSC you most likely have a vac leak at the bypass hose you can confirm by blocking off the TB and see if the car will idle. if your tuner has control of the IAC and can see the idle feedback change and you cannot drop the idle you have a leak somewhere after the TB.

Dave

 

[BATMANs]

1993 NSX

SOS SC

Anyone have pics of the by pass hose?

 

[DDozier]

1993 NSX

SOS SC

Anyone have pics of the by pass hose?

Everything I can offer is in this thread, I think the New complete SOS kit addresses this issue with a pipe like the replacement one for the CTSC, but that does not mean that the hose couplings have not pulled loose and caused the same issue, things are tight under the manifold and can be pulled loose if care is not taken. If you have a bore scope or camera you could view the two hose couplers without removing the blower and intake to check this off your list of possible issue.

You should also check the High Idle Valve for proper operation, if it is stuck open you will have the same issue.

http://www.nsxprime.com/forum/showthread.php/55269-Vacuum-leak-CTSC?highlight=bypass

Dave

 

[ScienceofSpeed]

Assuming the idle settings in the calibration are correct (idle, controlled by the idle air control valve, is configurable for 1991-94 applications) , the likely cause would be a vacuum leak.