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

KingKong8247 · 09-17-2002, 08:24 PM

Hey I posted the other day about my high idle but no one replied. And today my idle went up to about 1800 RPMs Sometimes it goes to about 1000 but usually its pretty high. Why is this doing this? It was all fine till about 2 or 3 weeks ago I bought some octane booster from the dollar store to see if it would help any and it just raised my idle. Thanks for the help

luke91 · 09-17-2002, 09:11 PM

I'll bet your throttle cable is sticking.  Disconnect your battery over night, one night, and if you still have a high idle, it's the throttle cable.  Just clean it up.  
--luke

Russki · 09-18-2002, 06:09 PM

I have the same problem, not sure if it's the same cause or not, but when my throttle position sensor is set properly, it idles at 1800-2000 rpm.  I adjusted the sensor all the way down to the lowest reading and now it idles at 800 or so, but that is just covering up the problem, not fixing it.  I have scratched my head over this many months now, and even the infiniti techs are puzzled.  One of them is very farmiliar with the 240's and he still didn't know what it was, I tried everything.  There is a small repair shop across ProjectD in Bloomington, MN that also know their 240's, but he said that it would take 2 days, 350 bux and he won't tell me what it is because he wants the business (obviously).  I hope yours is simpler than mine, but i guess i just wanted you to know you're not the only one with idle problems, they're very common.

240sxtreme · 09-18-2002, 06:17 PM

check the throttle cable, also, if after checking throttle cable and it still does it...check the throttle body, make sure it's closing...

my car did that when I first bought it...I'm pretty sure it's the cable, cause it went away after a week of driving it...

also.....changing the TPS sensor won't be good, unless you're also making sure you don't rev over 6k...because if you lower the TPS by 1k, then the tach is 1k too low..so if it shows you're going 6k, you're really going 7k....Does that make sense to anyone else but me...(scratches head)

Russki · 09-18-2002, 06:26 PM

That doesn't make sence because when i move the sensor, the actual idle goes down, not just the tach.

Oh yeah, and the engine shakes pretty bad at normal idle speed, but no power loss (at least i don't think so)

KingKong8247 · 09-18-2002, 07:01 PM

Hey, thanks for the replies.  I checked and its not the throttle cable cuz its definatlly not sticking.  Im gonna try disconnecting the battery tonite to see if anything happens.  It could be the throttle body but I dunno.  How would I go about checking that cuz my car doesnt start when the intake's off it just goes a little than stalls. Thanks

*DSC* · 09-18-2002, 08:33 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (luke91 @ Sep. 17 2002,12:11)</td></tr><tr><td id="QUOTE">I'll bet your throttle cable is sticking. Disconnect your battery over night, one night, and if you still have a high idle, it's the throttle cable. Just clean it up.
--luke</td></tr></table><span id='postcolor'>
What does disconnecting the battery over night do exactly?

09-17-2002, 08:24 PM	#1
KingKong8247 Zilvia Junkie Join Date: Mar 2002 Location: Jersey Age: 40 Posts: 555 Trader Rating: (0) Feedback Score: 0 reviews	Hey I posted the other day about my high idle but no one replied. And today my idle went up to about 1800 RPMs Sometimes it goes to about 1000 but usually its pretty high. Why is this doing this? It was all fine till about 2 or 3 weeks ago I bought some octane booster from the dollar store to see if it would help any and it just raised my idle. Thanks for the help __________________ 90 240sx Coupe

09-17-2002, 09:11 PM	#2
luke91 Zilvia Member Join Date: Sep 2002 Location: Pittsburgh, PA Age: 44 Posts: 218 Trader Rating: (0) Feedback Score: 0 reviews	I'll bet your throttle cable is sticking.  Disconnect your battery over night, one night, and if you still have a high idle, it's the throttle cable.  Just clean it up.   --luke __________________ '91 fastback.  '97 S13 blktop SR20DET.  Cstm Frnt Mnt IC w/ cstm 2 1/2" piping.  stnls stl fltr.  3" cstm DP & exhst w/N1 muff.  Walbro FP.  ACT 6 pck cltch.  Go Fast Bits crnk plly.  Ground Control coils.  KYB AGX shks.  12.98@106 w/g-tech pro.  17psi.  All work and fabrication done by ME

09-18-2002, 07:01 PM	#6
KingKong8247 Zilvia Junkie Join Date: Mar 2002 Location: Jersey Age: 40 Posts: 555 Trader Rating: (0) Feedback Score: 0 reviews	Hey, thanks for the replies.  I checked and its not the throttle cable cuz its definatlly not sticking.  Im gonna try disconnecting the battery tonite to see if anything happens.  It could be the throttle body but I dunno.  How would I go about checking that cuz my car doesnt start when the intake's off it just goes a little than stalls. Thanks __________________ 90 240sx Coupe

09-18-2002, 08:33 PM	#7
DSC New Title Join Date: Aug 2001 Location: VA Posts: 3,454 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (luke91 @ Sep. 17 2002,12:11)</td></tr><tr><td id="QUOTE">I'll bet your throttle cable is sticking. Disconnect your battery over night, one night, and if you still have a high idle, it's the throttle cable. Just clean it up. --luke</td></tr></table><span id='postcolor'> What does disconnecting the battery over night do exactly? __________________

09-18-2002, 06:09 PM	#3
Russki Leaky Injector Join Date: Feb 2002 Posts: 82 Trader Rating: (0) Feedback Score: 0 reviews	I have the same problem, not sure if it's the same cause or not, but when my throttle position sensor is set properly, it idles at 1800-2000 rpm.  I adjusted the sensor all the way down to the lowest reading and now it idles at 800 or so, but that is just covering up the problem, not fixing it.  I have scratched my head over this many months now, and even the infiniti techs are puzzled.  One of them is very farmiliar with the 240's and he still didn't know what it was, I tried everything.  There is a small repair shop across ProjectD in Bloomington, MN that also know their 240's, but he said that it would take 2 days, 350 bux and he won't tell me what it is because he wants the business (obviously).  I hope yours is simpler than mine, but i guess i just wanted you to know you're not the only one with idle problems, they're very common.

09-18-2002, 06:17 PM	#4
240sxtreme Zilvia Junkie Join Date: Oct 2001 Location: Portland, OR Age: 48 Posts: 386 Trader Rating: (0) Feedback Score: 0 reviews	check the throttle cable, also, if after checking throttle cable and it still does it...check the throttle body, make sure it's closing... my car did that when I first bought it...I'm pretty sure it's the cable, cause it went away after a week of driving it... also.....changing the TPS sensor won't be good, unless you're also making sure you don't rev over 6k...because if you lower the TPS by 1k, then the tach is 1k too low..so if it shows you're going 6k, you're really going 7k....Does that make sense to anyone else but me...(scratches head)

09-18-2002, 06:26 PM	#5
Russki Leaky Injector Join Date: Feb 2002 Posts: 82 Trader Rating: (0) Feedback Score: 0 reviews	That doesn't make sence because when i move the sensor, the actual idle goes down, not just the tach. Oh yeah, and the engine shakes pretty bad at normal idle speed, but no power loss (at least i don't think so)