i have set up v7 rom to full time open loop, i read here in this forum somewhere that only minor changes have to be made in the fuel and timing map at idle,otherwise you run the same setup as before because the car will go into open loop after a certain load...

but the thing is as i have set my car into open loop, now at crusing speed its very rich like 12 afr before it was 15.5 afr, i havent yet had a WOT run so cant tell about that..

my question is if i set my car into full time open loop what changes do i need to make to the fuel and ignition map?

and is it correct that i only have to make changes at idle 10-40 load and leave the rest of the map same?

 

You're going to have to tune the whole map buddy
Get logging!

 

you serious? and just the fuel or timing both?

 

Just fuel...

 

thank god and thank you sir,i was worried as hell!

 

In full-time open loop the car will only run using the fuel map, so the whole map needs to be completely dialed in.

 

i didnt understand by "In full-time open loop the car will only run using the fuel map"
so it will not be using the timing map?

 

No it means instead of using O2 sensor feedback to control fuel (ie closed loop), it will only use the value in the fuel table to determine fueling. Timing maps are used the same either open or closed loop so those should be good.

Also, if you WOT area of the fuel map was already tuned, that will stay the same, only the cruise and idle should need to be adjusted.

 

this is my current fuel map, can you guys plz point out the areas where i need to tune the fuel map, espically the cruise areas....

before my cruise area was 15.5 afr, yesterday it was in the 14.2 afr range, do i need to lean out the fuel map in those areas to bring it back to 15.5?

and also i saw 4-5 counts of knock in my logs at 2800-5500 rpm range, is it because im running rich in those areas?

 

save yourself a headache and run closed loop

 

if i run closed loop my idle afr's are near 17.0, but when i ran open loop they were back to normal 14.7-15.0

if you have any suggestions as to my my afr's are so lean at idle in closed loop plz give me some advice...the idle issue was the sole reason i went to open loop.

no matter what i did in closed loop the idle would stay lean,otherwise car was perfect at cruise and WOT.

 

if your running closed loop and your idle afrs are near 17 you probably have a bad front o2 sensor. the ecu has a lot of leeway and can add or remove a lot of fuel when in closed loop (+-25% something like that) so if your going lean in closed loop you've got an issue. Because the fueling is ok in open loop I would say consider replacing your front o2

I'm not sure why you wouldn't have any problems at cruise but its possible if/when you had the car tuned they set the open/closed loop switch over threshold very low so its really only running closed loop at idle. You would have to pull your rom and look at it to see if that is the case.

The image below shows the tables you are looking for although they can vary in location depending on if your running tephra or not. You can see in the picture I provided that this rom will switch to open loop at 45 load for the most part (or 25% throttle whichever comes first) 45 load is really just above idle load so during cruise this rom is in open loop almost all the time. See if your load numbers are similar or if your throttle numbers are fairly low (like 20% or something), my evo idles at about 13% throttle I think to give you a reference.

It wouldn't hurt to post up a list of your mods also. As far as tuning the car in open loop, it sounds like your just having idle issues if your fueling is fine during cruise and wot. I run my car in open loop all the time so I can have a leaner idle and cruise than 14.7.

 

okay here are my mods...

gsc s2 cams
aem wideband
walboro 255 lph pump
catless exhaust
gt35r

my idle throttle position is 12.5%

and the front o2 sensor is the one that plugs into the exhaust manifold right?

and here is my open loop load tables..

 

Post a log of your front o2 sensor and timing at idle. If there is a large variance in the voltage, that will confirm a bad o2. Mine is going out and that was pointed out to me, mine kept jumping from .1 to .9 and everywhere in between. There was no consistency in either timing or voltage from the o2.

 

so which parimeter should i log in evoscan, that logs front o2 sensor?

is it the oxygen feed back trim (STFT)

the oxygen sensor

the oxygen sensor #2

which one is it?