Nissan 200SX Club - South Africa

Did it influence your petrol usage?

Did it influence your petrol usage?

Depends how much time you spend idling. I get 450km per tank if I drive nicely so wouldnt really know if it affected it.

i get 550 on nice driving.

about 400-450 when i take it to the track!!!

Never footed a whole tank but I would get about 300km if I did.

Ok, I unplugged the idle valve plug, the problem was gone, the revs stayed stable.

There was 1 problem, ons starting the car you had to give gas to get it to idle and then it took a few seconds before the idling went to where it has to be.....that irretated me so I just put the plug back in, I will have to be happy with the way it is.

I don't like to open the idling screw because I believe some air pressure escapes there when you boost....that irretates me.

Ok, I unplugged the idle valve plug, the problem was gone, the revs stayed stable.

Why did you do this?? Which one did you unplug; the one at the front of the motor or the one at the middle??

I don't like to open the idling screw because I believe some air pressure escapes there when you boost

You are very mistaken... This is a idle air bypass valve. It bypasses the air from the throttle body to help the motor to idle. Air always flows through this valve even when boosting but it re-enters the plumen (so all it has done is reroute the air past the throttle)

Besides I said close the idle valve this would be in your favour if your thoughts were correct .

"You are very mistaken... This is a idle air bypass valve. It bypasses the air from the throttle body to help the motor to idle. Air always flows through this valve even when boosting but it re-enters the plumen"

I am just wondering, if the butterfly is closed the idle valve and screw bypasses air to let the car idle, now if you boost and the valve is stuck open then it means some of the air can escape there while boosting.....if the idling screw is open....if all is well and everything is working the way it should this will not happen but all is not well that is why the revs is so eratic.

actually I am not wondering....

Why did you do this?? Which one did you unplug; the one at the front of the motor or the one at the middle??

The copper round one, the idle valve against the plenum, I did this to see if it took away the eratic idling sometimes whitch it did....capish....

But the air isnt escaping, it is mearly being bypassed. As it is now the air is being "bypassed" when you boosting so by changing the valve position on idle isnt changing anything on boost, the air will still be bypassed.

Gary57 wrote:But the air isnt escaping, it is mearly being bypassed. As it is now the air is being "bypassed" when you boosting so by changing the valve position on idle isnt changing anything on boost, the air will still be bypassed.

Have you opened and cleaned the whole aluminum casting, you will see the idling screw has a type of rubber o-ring that stops air from escaping when it is opened, what do you think happens when this rubber o-ring is perished?

So your idle bypass valve is completely closed?? I am talking about the one in the center of the motor. If it is completely closed then yes no air is being bypassed, I said close it a bit to bring down the idle anyway. If it is completely closed and your idle is still high then something else has changed.

Ya I closed it completely because of the o ring. I set my idling with the manual butterfly screw, I don't know how the revs can still climb sometimes on idle because the valve is closed, the same with vlades if I am not mistaken, it seems the valve tells the computer electronically to up the idle sometimes and it gets air from somewhere else....the vacuum pipes from the plenum to the black scuare box underneath the butterfly, or from the PVC valve....but why does it up you idling only sometimes....even in very high heat....

Oh ok my bad now I understand. What does your car normally idle at??

The sx has 2 idle control valves. A stepper motor and the bypass valve, now your bypass valve is closed so it must be altering the idle via the stepper motor (this is the one in the front). I dont use this so not sure if it is adjustible.

I would try bring down your idle on the butterfly and let the computer correct it using the stepper motor.

Why dont you just change the o ring??

My car idles at 1.2, that is where i want it, the problem is only sometimes even in hot wheather when you slow down and idle in traffic the idling stays at 1.5 then you pull away, when you slow down again it is normal at 1.2, where I set it.....As I understand Vlade the same happens to him.

Ja but Vlades we can fix yours is not so easy cause your o ring is gone. Maybe fix it first then try sort the idle.

Gary57 wrote:Ja but Vlades we can fix yours is not so easy cause your o ring is gone. Maybe fix it first then try sort the idle.

but please pm me your number!