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View Full Version : How can I smooth idle with 272/272 cams



dwongcarreras
11-23-2010, 06:14 PM
I have read some on the forums and so far have:
1)Advanced timing from 5 to 7. from 0 to 1500 RPM on cell loads 0 to 40.
2)Increased minimum target idle from 790s to 1031.
with some improvement. but car keeps dipping from 1000 rpm to 650-700 rpm and jumping up to 1200-1300 rpm.
I have noticed the wideband go from 14.7 all the way down to 10.0 and coming back up.

Additionally when cruising the car will run fine @ 2000 rpm and over but when I let go of the gas it will stutter and drop the AFR to 11s.

This is a 2006 EVO 9. 272/272 cams. Custom cone intake. FMIC. UICP. LICP TBE.

http://i325.photobucket.com/albums/k379/dwongcarreras/Evo%20MAPs%20nov%2023/Screenshot2010-11-23at70745PM.png

http://i325.photobucket.com/albums/k379/dwongcarreras/Evo%20MAPs%20nov%2023/Screenshot2010-11-23at70719PM.png

http://i325.photobucket.com/albums/k379/dwongcarreras/Evo%20MAPs%20nov%2023/Screenshot2010-11-23at70646PM.png

http://i325.photobucket.com/albums/k379/dwongcarreras/Evo%20MAPs%20nov%2023/Screenshot2010-11-23at70613PM.png

any ideas? thanks for reading!

HMatt
11-23-2010, 09:36 PM
There is an Idle timing table... I forgot the proper name for it, but stock it basically allows the timing at idle to jump plus or minus 7 deg. If you cut that down to like 3, it helps.

For your afrs, take a look in your map. Sometimes the load cells around idle are set really friggin rich. You can adjust that.

For your idle jumping around, if you raised your idle to 1031, then you need to adjust your BISS (base idle set screw) on your throttlebody to that RPM. If you have a copy of evoscan, there is an actuator for you to adjust the BISS.

What type of 272's anyway? I'm ruling out HKS's because if you had those, your idle should be almost like stock with a IX.

silvrEVOIXn818
11-23-2010, 10:21 PM
28.8* is max MIVEC advance, so having 30's in there does nothing more than 28.8*!Â* Â*

U might need to advance timing to ~ 10* in the idle area, depending on which cams...Â* I have 7*, w/ the stock cams...Â*

The map hmatt is describing is the "low coolant temp timing trim map" which is sorta all over the place w/ -12*, and the next cell is -6*.Â* If you zero out this map, it will help stablize idle, but will take forever to warm up the car, so my advice is to set up the map, so that the timing being pulled is even so @ 1250 rpm, I have -5* from 30 - 60 load, -10* @ 1500 rpm, and from 30 - 60 load, and 1750 rpm has -15* to 50 load and 60 load has -10*.Â* And zero out the rest of the map.Â* This way it still warms up the car quickly, but doesnt affect driving.

1031 is fine for idle rpm, but sounds like u need to adjust the BISS, as HMatt has already pointed out.Â*

u might wanna zero out the mivec vs. coolant map @ operating temp and cooler, as u have quite a bit of mivec there.Â*

u might also wanna adjust the "desired iscv initial step position w/ ac on in nuetral and ac off drive".Â* Â*log iscv demand % and see where your @, as my maps were way high @ start up temp.Â* Â*Its said that the definitions for those 2 maps, arent even correct, but did help a lil.

and your fuel map looks WAY RICH from 160 load on!Â* And u need to smooth out the fuel map, as you have 12.5 @ 3500/120, and the next cell is 10.5 @ 3500/140.Â* Too much of a swing can also cause knock!

dwongcarreras
11-24-2010, 07:33 PM
For your idle jumping around, if you raised your idle to 1031, then you need to adjust your BISS (base idle set screw) on your throttlebody to that RPM. If you have a copy of evoscan, there is an actuator for you to adjust the BISS.

What type of 272's anyway? I'm ruling out HKS's because if you had those, your idle should be almost like stock with a IX.

Thanks for the reply.
I recently bought the car. The guy that sold it didn't know what brand the cams were.
Why do I need to use Evoscan when adjusting the BISS? what happens is you don't use the evoscan?

dwongcarreras
11-24-2010, 07:39 PM
U might need to advance timing to ~ 10* in the idle area, depending on which cams...Â* I have 7*, w/ the stock cams...Â*

The map hmatt is describing is the "low coolant temp timing trim map" which is sorta all over the place w/ -12*, and the next cell is -6*.Â* If you zero out this map, it will help stablize idle, but will take forever to warm up the car, so my advice is to set up the map, so that the timing being pulled is even so @ 1250 rpm, I have -5* from 30 - 60 load, -10* @ 1500 rpm, and from 30 - 60 load, and 1750 rpm has -15* to 50 load and 60 load has -10*.Â* And zero out the rest of the map.Â* This way it still warms up the car quickly, but doesnt affect driving.

1031 is fine for idle rpm, but sounds like u need to adjust the BISS, as HMatt has already pointed out.Â*

u might wanna zero out the mivec vs. coolant map @ operating temp and cooler, as u have quite a bit of mivec there.Â*

u might also wanna adjust the "desired iscv initial step position w/ ac on in nuetral and ac off drive".Â* Â*log iscv demand % and see where your @, as my maps were way high @ start up temp.Â* Â*Its said that the definitions for those 2 maps, arent even correct, but did help a lil.


Thanks for the tips...
I made some changes to the MAP.
Increased the timing from 7 to 10.
And set to 0 all the cells in the low coolant temp timing trim map except for the ones you mentioned for which I plugged in the numbers you suggested.
I did not get a chance yet to adjust the BISS cause it was dark but the car now when I put it in neutral while coming to a stop sometimes turns off. Scary...what do you think is happening.
And this desired iscv initial step position w/ ac on in nuetral and ac off drive...how do you log it???u do a cold start and start logging in Evoscan?

silvrEVOIXn818
11-24-2010, 08:04 PM
For your idle jumping around, if you raised your idle to 1031, then you need to adjust your BISS (base idle set screw) on your throttlebody to that RPM. If you have a copy of evoscan, there is an actuator for you to adjust the BISS.

What type of 272's anyway? I'm ruling out HKS's because if you had those, your idle should be almost like stock with a IX.

Thanks for the reply.
I recently bought the car. The guy that sold it didn't know what brand the cams were.
Why do I need to use Evoscan when adjusting the BISS? what happens is you don't use the evoscan?


really w/ 272's, u should be between 7-10* depending on which cams. lift/duration, etc. Use "trial and error" method, till you have it to your liking.

if you dont use evoscan to set it to SAS mode (speed adjustment screw), than the ecu will re-learn itself back to where it was, even w/ the change. Â*Setting it to SAS mode in evoscan allows the ecu to register it and set/keep it in the ecu.
you need to adjust the BISS. Then test it out. If it doesnt solve the stalling issue, change back the ISCV tables, as u havent logged it yet. But do the biss, and check FIRST, so you can narrow it down, to exactly what it is.

as far as the "desired ISCV" maps, you have to add the definition to evoscan, (ISCV % Demand) so you can log it. Theres a thread on evom. Keep in mind, I dont have cams, so my maps could be quite different from your car w/ cams. You need to log it, and until u do, I would put it back to stock.
Heres how to adjust the biss. I have mine set to 850 ish.
http://forums.evolutionm.net/ecuflash/378686-setting-base-idle-using-sas-mode.html

HMatt
11-24-2010, 09:42 PM
900-1000 rpm should be fine on the idle on a IX. I'm idling hks 280's nice and lopey on my VIII with the idle set around 1000.

But yes, adjust your BISS per the instructions on the link above. That might be your whole problem as far as the dieing goes.

dwongcarreras
11-28-2010, 04:20 PM
900-1000 rpm should be fine on the idle on a IX. I'm idling hks 280's nice and lopey on my VIII with the idle set around 1000.

But yes, adjust your BISS per the instructions on the link above. That might be your whole problem as far as the dieing goes.

Finally got a chance to adjust the BISS with the evoscan actuator. finally the car is idling around @950 without jumping or turning off when coming to a stop. Thanks for the advice.

dwongcarreras
12-01-2010, 03:35 PM
After a couple of days and small adjustments of the MAP to get better cruising I've noticed that somehow the idle when coming to a stop was back to what it was before with the car shutting off when releasing a gear and coming to a stop. Do you have to readjust the BISS with the evoscan actuator everytime you make a change to the MAP?
Was I doing this correctly. With the car warm and running I pressed the speed adjustment screw mode actuator (link engaged sound) and then started to turn the BISS counterclockwise until the idle came up to around 1k and the pressed the actuator button again (link disengaged sound). Is this the correct way of doing it?

HMatt
12-01-2010, 08:53 PM
You want to set it to what you youave your idle set to in your ecu. Then after that, you need to adjust you iac steps until it stops doing it all together.

Black Evo Beauty
12-01-2010, 11:58 PM
take it to good shop =]-----

dwongcarreras
12-02-2010, 04:43 PM
You want to set it to what you youave your idle set to in your ecu. Then after that, you need to adjust you iac steps until it stops doing it all together.

Finally started to figure it out.... I increased the values on the desired ISCV and the car will come down to 1.1k without stalling. Will have to continue experimenting with those values to bring the rpm down to 900.
Thanks for the advice.

HMatt
12-02-2010, 11:03 PM
Once you get it right for just normal driving, then you might want to make sure it still goes ok with the AC on. There is a separate IAC table for that.

Reese Tuning
12-03-2010, 11:28 AM
Idle the car at 17 degrees ;)

James

GokuSSJ4
12-03-2010, 01:44 PM
900-1000 rpm should be fine on the idle on a IX. I'm idling hks 280's nice and lopey on my VIII with the idle set around 1000.

But yes, adjust your BISS per the instructions on the link above. That might be your whole problem as far as the dieing goes.


I hate anything above 1k rpms on any cam profile...
I need to have my idle set and adjusted, thanks for the tip (you learned something new every day, since i have never looked into making adjustments)