[ThrusTs14]

Yes. just like the title. I have a rb20det in a s13 hb. It idles real good and steady when its not warmed up yet. BUt once i drive it, it starts to rough idle. How can i adjust the idle?? I did sum research on idleing valve and all that crap about rb but couldn't find none. So i wanted to know from u guys.

Thanks.

 

[atlong]

well that is odd mine does the EXACT opposite. idels like shit when its cold but then great after it warms up..

 

[Carl H]

sounds like the tps isnt set correctly.
try unplugging the grey plug on the tps when its warm and see what happens.
if it doesnt change then loosen the tps bolts and adjust the tps to the point where the idle changes.

 

[ThrusTs14]

I did sum more research and i herd sum rb owners usually change the temperture sensor whent hey do the swap?? IS that true?? does the temperture sensor have anything to do with my rough idle?? YEah im gonna try to play arond with the TPS.

And once again THANKS ALOT.

 

[shockster0429]

do you have a FPR? if you installed a walbro. you should have one if you dont, just installed mine today, fixed all bogging issues, and idle problems.

 

[Mavrick]

I did sum more research and i herd sum rb owners usually change the temperture sensor whent hey do the swap?? IS that true?? does the temperture sensor have anything to do with my rough idle?? YEah im gonna try to play arond with the TPS.

And once again THANKS ALOT.

The computer uses the temp sensor for idle inrichment when the motor is cold, once the motor is warmed up it uses the signals from the O2 sensor, MAF, Cam and Crank sensors to determine fuel delivery.

 

[Carl H]

The computer uses the temp sensor for idle inrichment when the motor is cold, once the motor is warmed up it uses the signals from the O2 sensor, MAF, Cam and Crank sensors to determine fuel delivery.

almost right but not quite.
nissan ecu uses the temp sensor to determine how hot the motor is running and what kind of tempature corrections to apply to the fuel and ignition maps.
however if the temp sensor goes bad then it can cause problems but not the ones described.