Adjusting idle - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

nieko · 07-03-2008, 12:55 AM

ok so ive been having idling problems and running rich lately and i tried a bunch of things but could not fix it. so i decided to take my throttle body from my old car and clean it out real good and slap it back on my new car. everything seems to work but the problem is. i took the little accelerator drum stopper screw out of my old throttle body. so the question is

Do i adjust my idle with the iacv and TPS unplugged and do it with the accelerator wire first?

then the iacv?

then the TPS?

please help you guys... thanks

xsparc · 07-03-2008, 12:58 AM

first adjust your throttle plate screw, then your cable, then the TPS, then i iacv

nieko · 07-03-2008, 01:46 AM

ok, anyone else clarify this? i just want to make sure

thanks..

oh and how do u adjust the screw first?

should i unplug iacv and tps while doing this?

should the motor be at 750 before the tps and iacv?

ahh sorry, thanks

xsparc · 07-03-2008, 01:52 AM

the screw should be about half way, just make sure the plate is a hair off fully closed. you can do this with the car off.

the tps neds to be at like .45 volts closed and over 4.55 volts fully open. you need the car on for this, but not running.

timing needs to be at 15 before you do the iacv to set idle at 750

nieko · 07-03-2008, 12:16 PM

its werid because ever since i messed with it, i cant get the TPS to get to the right voltage... pissing me off and running not so well...

xsparc · 07-03-2008, 12:23 PM

cant get it low or high enough?

SoguRacing · 07-03-2008, 12:29 PM

ok, to set the idle, unplug the tps sensor, adjust the throttle body screw-loosen it so that the throttle plate is completely shut then tighten the screw so that it "just" touches the throttle plate lever..then tighten the screw "one" and only "one" full turn. no more!! then plug in the tps sensor and adjust the iacv to your desire. have fun!!

nieko · 07-03-2008, 12:50 PM

cant get it high enough... lol (voltage)

nieko · 07-03-2008, 03:29 PM

xsparc come in lol

nieko · 07-04-2008, 02:25 AM

alright so... i did the steps sogu said but the idle was still pretty high so i loosened the throttle body nut a little bit

and got it to 750 rpms and it idled like a champ nice and steady. then i pull out of my driveway and wait a second in

neutral and my idle slowly went up to 1800 rpms and stayed for awhile then slowly went back down. and i would

drive it and it would seem pretty good i guess and id stop at a light and it would idle solid 750. then the next like it

would slowy go up to 1800 again and stay there and it just keeps doing that crap.... im guessing something to do

with TPS? damn idk but this shit is getting annoying lol... oh also i am still running a rich and when i stand in front of

the engine bay and i tap the throttle, when the rpms go down is sounds like its backfiring in the back of the valve c

cover, or misfiring or something. its really weird. timing is set also. please help...

nieko · 07-04-2008, 02:30 AM

edit: tps is at the right voltage now also

SoguRacing · 07-04-2008, 11:57 AM

i'm not sure what it could be. maybe try setting your tps voltage to 4.5 volts ( on the lower range) and make sure your iac valve is pretty much closed. you dont want it open too much because the ecu can adjust that via current to the iac motor.

littlekids13 · 07-04-2008, 12:05 PM

try cleaning the iacv with carb cleaner worked for my fucked up idle it doesnt drop or go up anymore

nieko · 07-04-2008, 12:14 PM

ya i already cleaned it out dude... alright il try that but i think the screw is almost all the way in =X

nieko · 07-04-2008, 02:24 PM

update...... loosened stop screw on throttle body a little more and got my idle back at 750. tried adjusting tps, i could only get .20 volts before it turned on(off?) and my rpms shot up... i know its supposed to be .45 but... is this ok? it seems to be running a little rich but my idle problem is fixed. damn this motor... lol

07-03-2008, 12:55 AM	#1
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	Adjusting idle ok so ive been having idling problems and running rich lately and i tried a bunch of things but could not fix it. so i decided to take my throttle body from my old car and clean it out real good and slap it back on my new car. everything seems to work but the problem is. i took the little accelerator drum stopper screw out of my old throttle body. so the question is Do i adjust my idle with the iacv and TPS unplugged and do it with the accelerator wire first? then the iacv? then the TPS? please help you guys... thanks

07-03-2008, 12:58 AM	#2
xsparc Zilvia Junkie Join Date: Dec 2002 Location: san diego area - esco Posts: 461 Trader Rating: (0) Feedback Score: 0 reviews	first adjust your throttle plate screw, then your cable, then the TPS, then i iacv __________________ No... no one stole my interior... its safely in my garage...

07-03-2008, 01:52 AM	#4
xsparc Zilvia Junkie Join Date: Dec 2002 Location: san diego area - esco Posts: 461 Trader Rating: (0) Feedback Score: 0 reviews	the screw should be about half way, just make sure the plate is a hair off fully closed. you can do this with the car off. the tps neds to be at like .45 volts closed and over 4.55 volts fully open. you need the car on for this, but not running. timing needs to be at 15 before you do the iacv to set idle at 750 __________________ No... no one stole my interior... its safely in my garage...

07-03-2008, 12:23 PM	#6
xsparc Zilvia Junkie Join Date: Dec 2002 Location: san diego area - esco Posts: 461 Trader Rating: (0) Feedback Score: 0 reviews	cant get it low or high enough? __________________ No... no one stole my interior... its safely in my garage...

07-03-2008, 12:29 PM	#7
SoguRacing Post Whore! Join Date: Nov 2007 Location: (714) Age: 39 Posts: 2,967 Trader Rating: (23) Rides Gallery: SoguRacing Feedback Score: 23 reviews	ok, to set the idle, unplug the tps sensor, adjust the throttle body screw-loosen it so that the throttle plate is completely shut then tighten the screw so that it "just" touches the throttle plate lever..then tighten the screw "one" and only "one" full turn. no more!! then plug in the tps sensor and adjust the iacv to your desire. have fun!! __________________ Pre Tune Checkup! Compression,LeakDown,Vacuum Test $80. Cams Install: $180

07-03-2008, 01:46 AM	#3
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	ok, anyone else clarify this? i just want to make sure thanks.. oh and how do u adjust the screw first? should i unplug iacv and tps while doing this? should the motor be at 750 before the tps and iacv? ahh sorry, thanks

07-03-2008, 12:16 PM	#5
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	its werid because ever since i messed with it, i cant get the TPS to get to the right voltage... pissing me off and running not so well...

07-03-2008, 12:50 PM	#8
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	cant get it high enough... lol (voltage)

07-03-2008, 03:29 PM	#9
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	xsparc come in lol

07-04-2008, 02:25 AM	#10
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	alright so... i did the steps sogu said but the idle was still pretty high so i loosened the throttle body nut a little bit and got it to 750 rpms and it idled like a champ nice and steady. then i pull out of my driveway and wait a second in neutral and my idle slowly went up to 1800 rpms and stayed for awhile then slowly went back down. and i would drive it and it would seem pretty good i guess and id stop at a light and it would idle solid 750. then the next like it would slowy go up to 1800 again and stay there and it just keeps doing that crap.... im guessing something to do with TPS? damn idk but this shit is getting annoying lol... oh also i am still running a rich and when i stand in front of the engine bay and i tap the throttle, when the rpms go down is sounds like its backfiring in the back of the valve c cover, or misfiring or something. its really weird. timing is set also. please help...

07-04-2008, 02:30 AM	#11
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	edit: tps is at the right voltage now also

07-04-2008, 11:57 AM	#12
SoguRacing Post Whore! Join Date: Nov 2007 Location: (714) Age: 39 Posts: 2,967 Trader Rating: (23) Rides Gallery: SoguRacing Feedback Score: 23 reviews	i'm not sure what it could be. maybe try setting your tps voltage to 4.5 volts ( on the lower range) and make sure your iac valve is pretty much closed. you dont want it open too much because the ecu can adjust that via current to the iac motor. __________________ Pre Tune Checkup! Compression,LeakDown,Vacuum Test $80. Cams Install: $180

07-04-2008, 12:05 PM	#13
littlekids13 Join Date: Jun 2008 Location: the valley Posts: 7 Trader Rating: (0) Feedback Score: 0 reviews	try cleaning the iacv with carb cleaner worked for my fucked up idle it doesnt drop or go up anymore

07-04-2008, 12:14 PM	#14
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	ya i already cleaned it out dude... alright il try that but i think the screw is almost all the way in =X

07-04-2008, 02:24 PM	#15
nieko Post Whore! Join Date: Sep 2007 Location: Westminster Age: 34 Posts: 2,695 Trader Rating: (14) Feedback Score: 14 reviews	update...... loosened stop screw on throttle body a little more and got my idle back at 750. tried adjusting tps, i could only get .20 volts before it turned on(off?) and my rpms shot up... i know its supposed to be .45 but... is this ok? it seems to be running a little rich but my idle problem is fixed. damn this motor... lol