KA24E Bouncing idle at start up. High idle. Drives fine though? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

SilviaT · 02-20-2012, 05:39 PM

So i swapped out my blown ka24e with a replacement motor i bought off craigslist. Everything during the swap went fairly smooth, besides replacing my timing chain, guides, tensioner, and having my exhaust welded.
The car has a stock intake with a K&N filter, obx headers, no cat, with a 2.5" inbetween muffler and resonator. I deleted the EGR, AIV, CRUISE CONTROL, A/C, and the charcole canister. My plugs are fine, and it starts within the first turn over all the time.
HERES MY QUESTION.
When i turn it on when cold, my idle will bounce from 1200rpms-1700-ish for about 5 seconds.. Then it will settle around 1000-1200rpms. Why does it do this?
and while driving, usually the idle will sit at about 1200. but sometimes it will just sit at 1700...? Im not sure why... Any advice will be GREATLY appreciated.

waxball88 · 02-20-2012, 05:41 PM

Vac leaks.
Mine was doing this, i tightened all clamps and it went away. But it has been slowly creeping back into existence being that i'm boosted.

SilviaT · 03-01-2012, 12:08 AM

I checked all my hoses and everything is tight as should be.
The past few days it has been very cold out (20-30*) at night and snowing lightly during the day. My car will BOG/hesitate a littleeee bit at about 2500-300rpms in 2nd gear, and the same in 3rd but barely noticable. It does the 3/4 start ups until the engine is fully warm. I dont drive great distances much.
And so my guess is that my spark plugs are either fouled, (i had run seafoam before and didnt change the plugs or check them because my 4th spark plug is a little stript...) OR that when i replaced my timing chain guides and had to remove the TC cover, i re-timed my car and it felt most healthy at -15BTDC and i heard that it should sit at -10BTDC and adjust my idle to 800 or so...
PLEASE HELP/ ADVICE IS APPRECIATED

SilviaT · 03-01-2012, 12:12 AM

BTW my idle does not bounce like it used to as much nearly at all.. It sits at around 1100-1500 on the regular but when warm about 950-1100

240sohc · 03-01-2012, 07:52 PM

Check your coolant temperature sensor for build up, clean it or just replace it. Adjust your iacv to get your idle down, theres a screw attached to it that you turn to do this.

SilviaT · 03-02-2012, 02:03 AM

Thanks for the advice! Today i was cleaning the entire care as well as engine bay and made sure i did not have any vacuum leaks, or loose connections. I made my connection to my coolant temperature sensor tighter, and my idle did not really bounce. Just sat a little bit high (1100-1400) and after warm, it sits at around 1100.. I will clean it tomorrow and also try to adjust my iacv.
And sooooooooooooooo
MY HESITATION ISSUE:
When i start the car in the morning, i let it warm up for a few minutes and when i start to go down the street, I feel like im attempting to drive up a slight hill when im really on flat.. It isnt very noticable when the car is warm. The loss of power is reallllly annoying and i need to fix it.. The hesitation is only there around 2500-3100 almost constantly in gears 1,2 and 3.. and then i get my power back. What should i do??!
ALSO, last but not least... When cold, i hear a slight chatter in the back of my valve cover and i believe that is a sticky lifter.... Im 99% sure its not my timing chain since i JUST replaced the chain, guide and tensioner (s14 metal backed guides) so it shouldnt be my guides being broken or anything. My chain is tight, not loose. But maybe my timing is just off a little bit? I had it set to TDC and my oil gear is properly alligned. Maybe i need to set it to -10 btdc instead of -15? (thats where it felt most comfortable, less shake)
Thank you for your help who ever is reading this post.
I frequently google my problems and do not rely on my subscription to zilvia to get my feedback believe me. My dad helps alot with my trouble shooting but yet, he is 62 and imports are not quite his speciatly.....
PLEASE HELP AND THANK YOU TONS.

02-20-2012, 05:39 PM	#1
SilviaT Zilvia Member Join Date: May 2011 Location: NW Oregon Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	KA24E Bouncing idle at start up. High idle. Drives fine though? So i swapped out my blown ka24e with a replacement motor i bought off craigslist. Everything during the swap went fairly smooth, besides replacing my timing chain, guides, tensioner, and having my exhaust welded. The car has a stock intake with a K&N filter, obx headers, no cat, with a 2.5" inbetween muffler and resonator. I deleted the EGR, AIV, CRUISE CONTROL, A/C, and the charcole canister. My plugs are fine, and it starts within the first turn over all the time. HERES MY QUESTION. When i turn it on when cold, my idle will bounce from 1200rpms-1700-ish for about 5 seconds.. Then it will settle around 1000-1200rpms. Why does it do this? and while driving, usually the idle will sit at about 1200. but sometimes it will just sit at 1700...? Im not sure why... Any advice will be GREATLY appreciated.

03-01-2012, 07:52 PM	#5
240sohc Zilvia Member Join Date: Jan 2010 Location: park bench Posts: 206 Trader Rating: (14) Feedback Score: 14 reviews	ka24e bouncing idle at startup Check your coolant temperature sensor for build up, clean it or just replace it. Adjust your iacv to get your idle down, theres a screw attached to it that you turn to do this.

02-20-2012, 05:41 PM	#2
waxball88 Zilvia FREAK! Join Date: Jun 2009 Location: Gainesville Posts: 1,061 Trader Rating: (9) Feedback Score: 9 reviews	Vac leaks. Mine was doing this, i tightened all clamps and it went away. But it has been slowly creeping back into existence being that i'm boosted.

03-01-2012, 12:08 AM	#3
SilviaT Zilvia Member Join Date: May 2011 Location: NW Oregon Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	I checked all my hoses and everything is tight as should be. The past few days it has been very cold out (20-30*) at night and snowing lightly during the day. My car will BOG/hesitate a littleeee bit at about 2500-300rpms in 2nd gear, and the same in 3rd but barely noticable. It does the 3/4 start ups until the engine is fully warm. I dont drive great distances much. And so my guess is that my spark plugs are either fouled, (i had run seafoam before and didnt change the plugs or check them because my 4th spark plug is a little stript...) OR that when i replaced my timing chain guides and had to remove the TC cover, i re-timed my car and it felt most healthy at -15BTDC and i heard that it should sit at -10BTDC and adjust my idle to 800 or so... PLEASE HELP/ ADVICE IS APPRECIATED

03-01-2012, 12:12 AM	#4
SilviaT Zilvia Member Join Date: May 2011 Location: NW Oregon Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	BTW my idle does not bounce like it used to as much nearly at all.. It sits at around 1100-1500 on the regular but when warm about 950-1100

03-02-2012, 02:03 AM	#6
SilviaT Zilvia Member Join Date: May 2011 Location: NW Oregon Posts: 166 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the advice! Today i was cleaning the entire care as well as engine bay and made sure i did not have any vacuum leaks, or loose connections. I made my connection to my coolant temperature sensor tighter, and my idle did not really bounce. Just sat a little bit high (1100-1400) and after warm, it sits at around 1100.. I will clean it tomorrow and also try to adjust my iacv. And sooooooooooooooo MY HESITATION ISSUE: When i start the car in the morning, i let it warm up for a few minutes and when i start to go down the street, I feel like im attempting to drive up a slight hill when im really on flat.. It isnt very noticable when the car is warm. The loss of power is reallllly annoying and i need to fix it.. The hesitation is only there around 2500-3100 almost constantly in gears 1,2 and 3.. and then i get my power back. What should i do??! ALSO, last but not least... When cold, i hear a slight chatter in the back of my valve cover and i believe that is a sticky lifter.... Im 99% sure its not my timing chain since i JUST replaced the chain, guide and tensioner (s14 metal backed guides) so it shouldnt be my guides being broken or anything. My chain is tight, not loose. But maybe my timing is just off a little bit? I had it set to TDC and my oil gear is properly alligned. Maybe i need to set it to -10 btdc instead of -15? (thats where it felt most comfortable, less shake) Thank you for your help who ever is reading this post. I frequently google my problems and do not rely on my subscription to zilvia to get my feedback believe me. My dad helps alot with my trouble shooting but yet, he is 62 and imports are not quite his speciatly..... PLEASE HELP AND THANK YOU TONS.