k20z3 dc2 idle drop while rolling only when warmed up
Thread Starter
Honda-Tech Member
Joined: Jan 2010
Posts: 15
Likes: 1
From: New Jersey
k20z3 dc2 idle drop while rolling only when warmed up
Hey guys, so the title says it all. ive been having this issue for some time and working on it on and off, confirmed and checked many things and also scrolled through many threads on the internet for similar issue but not quite the same problem as im having.
Here are some specs:
k20z3 Dc2 on kpro v3 tuned
motor is internally stock as is trans/clutch etc
rywire kswap harness, ktuned conversion harness
k tuned fuel system but stock injectors 255 pump
karcpets adapter plate with stock tb with new oem iacv and k tuned hall affect tps
hybrid intake, karcepts header oem type s o2, 3in ss mandrel bent exaust to a vibrant uqr
using the ktuned vss calibrator as well if that matters.
My issue is that when the vehicle is warmed up to 180 the rpm will drop to about 500-650 range only when rolling, the second i come to a stop it shoots back up to the target idle perfectly, the car has absolutely no drive-ability issues or CELs present. I checked a lot of wiring for the o2, vss, tps everything is in order with no resistance issues, as well as the components themselves are new. i have oem coil packs and spark plugs new as well. At this point i am wondering if it has something to do with tuning. This issue did not make itself present until i had a tps and iacv issue where i ended up replacing both as the bearing in the iacv was unable to spin freely even with cleaning as well as the tps simply going bad. After replacing and calibrating everything was fine, this was earlier this year during colder weather so the problem had not shown itself.
one thing that bothers me is im unable to determine my a/f ratio even though i have my o2 setup with built in wideband oem on kpro
side note: does anybody know how i can upload the my calibration to this thread. in the mean time i will post a link to the Calibration i put on a hondata forum
https://www.hondata.com/forum/viewto...p?f=12&t=22512
use file - droppp.kdl
Here are some specs:
k20z3 Dc2 on kpro v3 tuned
motor is internally stock as is trans/clutch etc
rywire kswap harness, ktuned conversion harness
k tuned fuel system but stock injectors 255 pump
karcpets adapter plate with stock tb with new oem iacv and k tuned hall affect tps
hybrid intake, karcepts header oem type s o2, 3in ss mandrel bent exaust to a vibrant uqr
using the ktuned vss calibrator as well if that matters.
My issue is that when the vehicle is warmed up to 180 the rpm will drop to about 500-650 range only when rolling, the second i come to a stop it shoots back up to the target idle perfectly, the car has absolutely no drive-ability issues or CELs present. I checked a lot of wiring for the o2, vss, tps everything is in order with no resistance issues, as well as the components themselves are new. i have oem coil packs and spark plugs new as well. At this point i am wondering if it has something to do with tuning. This issue did not make itself present until i had a tps and iacv issue where i ended up replacing both as the bearing in the iacv was unable to spin freely even with cleaning as well as the tps simply going bad. After replacing and calibrating everything was fine, this was earlier this year during colder weather so the problem had not shown itself.
one thing that bothers me is im unable to determine my a/f ratio even though i have my o2 setup with built in wideband oem on kpro
side note: does anybody know how i can upload the my calibration to this thread. in the mean time i will post a link to the Calibration i put on a hondata forum
https://www.hondata.com/forum/viewto...p?f=12&t=22512
use file - droppp.kdl
Thread Starter
Honda-Tech Member
Joined: Jan 2010
Posts: 15
Likes: 1
From: New Jersey
Re: k20z3 dc2 idle drop while rolling only when warmed up
Was driving the car yesterday but didnt have my computer when i noticed when the vehicle was on the colder side of ambient air temp and water temp the rolling rpm would be raised slightly to around 1200 steadily. showing signs of the exact opposite as compared to reactions when warm
any ideas guys? im wondering if i have to tweak something in my tune.
any ideas guys? im wondering if i have to tweak something in my tune.
Thread Starter
Honda-Tech Member
Joined: Jan 2010
Posts: 15
Likes: 1
From: New Jersey
Re: k20z3 dc2 idle drop while rolling only when warmed up
figured i would revive this and give a more accurate description of whats going on as i still have yet to figure this out.
-The vehicle itself has no issues with idle characteristics, it is only as the vehicle starts to roll that the RPMs begin to drop to 650 when warmed up. the second the car stops the rpm will recover to 850. the only difference when the vehicle is cold is that the rpm will raise to 1150 and again once stopped recover to 850.
-the vehicle does not need any input what so ever for this to occur, just simply keeping it in neutral and releasing the e-brake allowing the car to roll is all it takes for the affect to occur.
At this point the only things that i feel could be causing this are either vss related, iacv related(although i have a new one), or something to do with closed loop. perhaps i am not setup correctly although i do have the correct oem o2 in place i also do not seem to get a value on the a/f display
edit- for the record i have since only tried zeroing out the low cam angle speed below 1500 and from 1500-2250 i interpolated but that did not seem to fix the issue.
-The vehicle itself has no issues with idle characteristics, it is only as the vehicle starts to roll that the RPMs begin to drop to 650 when warmed up. the second the car stops the rpm will recover to 850. the only difference when the vehicle is cold is that the rpm will raise to 1150 and again once stopped recover to 850.
-the vehicle does not need any input what so ever for this to occur, just simply keeping it in neutral and releasing the e-brake allowing the car to roll is all it takes for the affect to occur.
At this point the only things that i feel could be causing this are either vss related, iacv related(although i have a new one), or something to do with closed loop. perhaps i am not setup correctly although i do have the correct oem o2 in place i also do not seem to get a value on the a/f display
edit- for the record i have since only tried zeroing out the low cam angle speed below 1500 and from 1500-2250 i interpolated but that did not seem to fix the issue.
Thread Starter
Honda-Tech Member
Joined: Jan 2010
Posts: 15
Likes: 1
From: New Jersey
Re: k20z3 dc2 idle drop while rolling only when warmed up
RESOLVED
what i found was that after installing the vss i assume the ecu sort of takes readings from the vss to figure out idle air flow. what i believe happened was it was essentially fighting itself. the only way i was able to resolve this issue was by opening the throttle body itself further(while hot), then calibrating. after that everything was fine.
what i found was that after installing the vss i assume the ecu sort of takes readings from the vss to figure out idle air flow. what i believe happened was it was essentially fighting itself. the only way i was able to resolve this issue was by opening the throttle body itself further(while hot), then calibrating. after that everything was fine.
Last edited by x LSDxB20 x; Dec 27, 2020 at 11:43 PM.
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