hello already install the new engine with a single kit on it but whe are about to instal the power fc. i know 99 percent of the rat nest vacs ripp of also the solenoids but in my search some people leave ones, some people dont, some people removed all.. i just want to make sure wich one to kept and wich one to go just want my engine bay as clean as posible.

thanks

 

If you do not have to worry about emmissions, and are using an external boost controller, remove all except ISC.

I do not even run the ISC.

 

what is ISC ?

 

The ISC is the Idle Speed Controler mounted on the front side of your UIM.
The UIM is the Upper Intake Manifold incase you did not know that too. The ISC is the only one I left on mine.

 

ok thanks for the help

its The ISC that will allowto set a steady iddle?

why cannot be removed?

if also beed told not to remove the pfr solenoid i dont know if its true or not?

thanks i begin doing the cleaning of vacs and solenoid today ill post more info in advance

 

what happen if ISC has removed ?? rough idle ??

 

IDLE-SPEED CONTROL (ISC) SYSTEM

DESCRIPTION

Idle speed control (ISC) system controls the bypass air amount that passes through the throttle valve, the idle-speed control system performs feedback control so that engine idle smoothly and at the target speed. The system also performs the function of the AAV (anti-afterburns valve), there by eliminating the AAV and simplifying deceleration control system.

F-81 of 1993 RX-7 Workshop Manual


Removing...

+ idle timing can be changed (uses maps instead of hard coding)
+ may correct surging idle from the ISC being "out of range"
+ may solve problems with a faulty ISC (carboned up ISC is common)
- requires PowerFC & Datalogit (must set idles to 0 RPM)
- idle speed may need small adjustments from season to season
- car may die more easily or not idle correctly
- popping and backfires may be more common

The more mods the car has the more out of range the ISC becomes. Closing the throttle plates with the air-adjusting screw (under the elbow) can help bring the ISC back into range if idle surging is a problem. After many mods, strange idle behaviour may be noticed. I recommend keeping the ISC unless there is a problem with idle that can't be solved by other routes.

 

thanks for the help i think that will be the only solenoid that will stay, but if the ISC is removed the iddle cannot be adjusted via the power fc?i been told that i will be able to control the iddle close to perefection wit the power FC

 

That's correct. Without the ISC, you would have to manually adjust the idle under the hood. With the ISC, you just set the idle RPM with the Commander or Datalogit. The idle settings really don't need to be changed very often though.

 

I just want to make sure it is ISC, thx

cuz in the workshop manual, it said Idle air control valve

thx

 

If ISC is disable, where can i adjust the idle ? Do i adjust the idle in the screw that under the elbow ?

thx

 

Yes, the screw under the elbow is the fine idle adjustment and likely the only one that needs to be adjusted.

 

Thanks Matt.

Could you answer my prior question with the picture, i want to make sure that is ISC.

If not where is the ISC

thx

 

Yes, that's the ISC under the double throttle. Since you have the workshop manual maybe you should read F-81 (that's section F page 81) which I referenced in my first post. It shows several pics but they're not the greatest.

 

thank you very much !!!

Well, i have ISC only now, i cut the solenoid connectors and sth that i dont really needed