wierd problem idle on s14 sr20

[240sxxs]

yes i have search but not alot of peoples havethe same symptom as me ... but when im in gears the car run fine ,but when there a red light ahead , throw back to neutral,then my rpm drop then it bouncing around from 600 to 1300 rpm then it keep doing that while my car free-roll on neutral until my car is dead stop , then the idle turn back to be normal at exactly at 800. i live in arizona where is either really hot or cold... and i noticed it is only happen when the weather is cold..when is hot the problem doesnt seem to happen. NO CEL , no sputtering , no deaccelerate feeling or anything...

[rebornS14]

what ecu are you running?

[240sxxs]

im running on MAP PowerFC D-jetro

[240sxxs]

bump ................

[240sxxs]

no one knows what the fuck happen ... i change coilpack but not spark plugs yet so which spart plug i should go for...

[SleepR 240sx]

Is your BOV recirculated? If not that is probably it. When you drop into neutral you are leting out air that has already been metered by the MAF.

Could also be your IACV needs cleaning or a vaccuum leak. Try cleaning your MAF sesnor as well, but I would put money on it being your BOV. Very common issue. You will always run rich if it is unrecirculated.

[jackal264]

he said he's running map so bov means nothing. i had a similar issue with my s14 sr running a tomei reytec. we finally diagnosed it and the motor was running to cold, it was dumping extra fuel b/c it was always in warm up mode. i am running a koyo + nismo t-stat and fal's and i was sitting at like 160. we eventually just went into reytec and changed the settings so that the warm up fuel correction stopped at 155 instead of the original 165

also one of the first things i did was to up the idle to 1000 which has helped a handfully of stories that i had found do to running such big injectors. it your running 740's try just upping the idle, sometime the injectors are so far out of their optimal range they don't particulate the fuel very well causing them to dump to much fuel.

both are really easy checks try them see what happens

[240sxxs]

lol jackal are so right...well i live in arizona ..in summer time , the weather can goes up to like 100-120 and my car idle and run perfectly fine... but in the winter time it run extra cool or even cold....now like i said i have no problem with the car in the days..when there somewhat heat even in cold weather, but as soon as the sun setdown and temperature drop to ....let say from 90-to like 80-75 , it will still idle fine , drive fine, but as soon as i shift back to neutral , the rpm drops and bouncing between 500-1200 then it keep doing that and keep bouncing until my car at dead stop... then it idle at exact 800.... to jackal my car never pass 71 Celsius at night time and same as in the days..but it onlu happen when sun down..and i am running 740s sard injector..so right now i need to change my idle too 1k rpm ??

[240sxxs]

if i have a vacumm leak then would my idle will be bouncing when im at dead stop ?? lol but is not... and alot of peopel said maybe is my iacv also

[fliprayzin240sx]

if i have a vacumm leak then would my idle will be bouncing when im at dead stop ?? lol but is not... and alot of peopel said maybe is my iacv also

Vacuum leak wouldnt mean shit since you're running a D-jetro.
Personally, since its not killing the car when you come to a stop, I wouldnt even worry about it.

See if you can play around with the PFC and see what your idle setting is in there. Try bumping the PFC idle setting, that might help.

[240sxxs]

yea today i mess with idle screw and the idle stop doing it when the car warm up...i just test drive the car and it still bouncing when i throw back to neutral but it not as bad as other time..it help alot..so i went to market and i park the car and it reach 70Celsius and idle at 900-1000 and it good...and yes im running on map..so wouldnt matter i forgot about thta

[240sxxs]

well what else could it be..