*How to setup idle for AEM ECU*
 

So after a few years of tuning the aem i believe i have finnally figured out how to get the idle to stay consistant. I know alot of the self tuners out there like me have been having problems for a while now. Lets see if this can fix them. I have already tested this on my evo 8 and a friends K24 honda which had similar inconsistant idle issues. Fixed both. Its all about finding the sweet spot. I'm going to start from the basics of how to setup idle with aempro so everyone can follow and understand. For those of you that cant get the car to idle at all see this thread first.....
http://forum.aempower.com/forum/inde...c,13376.0.html

First thing that needs to be done is turn the 02 feedback off. Open Idle/Idle target base table/Table. This is where you will set the desired idle rpm.
Lets start with these settings.

-40 to 68=1400rpm
86=1350rpm
104=1325rpm
122=1300rpm
140=1250rpm
158 to 248=1200
This will give a 1200rpm idle when the engine is warm. 158F+ ECT and 1400 when cold -68F ECT.

Get the car started and idleing somewhat steady. You may have to baby it until you can get it to steady out from the idle feedback working. open idle templates.

You may have an Idle Learned value of +/- 5. This is normal at this point. Adjust the fuel table until you can at least keep the AFR in the 14's when the engine is at full temp. At this point the idle should be around 1200rpm. Monitor the idle learned value,Adjust the Idle% vs Target graph/table at the 1200rpm point up if the feedback is negative or down if the feedback is positive. Adjust unitl the feedback value is staying around 0. Now, go back to Idle/Idle target base table/Table. Change the 158 to 248 value to 1300rpm. The engine should idle up, give is a few seconds to stablize. Adjust the Idle% vs Target graph/table at the at the 1300rpm point until it is around 0. Do this all the way up to 1600rpm adjusting the idle% at every rpm point so that at all commanded rpm points the idle feedback is around 0. Change the commanded idle (Idle/Idle target base table/Table) to 1100 rpm if it can idle somwhat stable adjust the Idle% until you have near 0 feedback (idle feedback value). Do this at 1000rpm,900rpm,ect. or until you reach an rpm where the engine wont idle. Once this is done you will be able to see the "curve" of the Idle% vs Target graph. Take the rpms point the engine would not idle at and smooth them making the table have a consistant curve. example: 1000rpm=35% 900rpm=33% 800rpm=30% an so on.
Also, adjust the 1700rpm-1800rpm the same way. Make 1900rpm and up all the same % making the curve go flat at 1900rpm-3000rpm.

Now set the idle base back to 1200rpm. At this point the engine should be idleing fairly well. Turn the engine off. Start with these values.
High idle car speed=255
High idle rpm offset=0
High idle wait time=0
Idle off if tp over=2%
Idle on if tp less=2%
Idle feedback above rpm=400rpm
Idle feedback below rpm=1800rpm
Idle a/c load comp=5% This may need to be moved up or down if the idle feedback has excessive values. ie:greater then 4%
A/c on delay=1 S

Go to Configure/ECU setup/Set throttle range. Follow the instructions to setup
the TPS.This is where it gets tricky!!!!!!!!! You should now have a tps reading of 0.
Go to Setup/Sensors/Throttle position sensor/Options. Monitor the throttle % and move the TPS min. voltage down in .02 increments until the throttle % shows around .5% Example: 0.70 / 0.68 /0.66,ECT. If the throttle % EVER shows 0 some of the idle tables will be turned off!!This is a problem with the software imo and took me years to figure out. The throttle % will change from when the engine is cold to when it is warm. The trick is to never let the Throttle % read 0. If it does the idle goes all to hell. At the same time throttle %must never be above the
2%. Watch it during cold start and when the engine is hot, adjust accordingly to keep is between .5-2%

Go to the Ignition table and set the all the cells near the where the car is idling to 10 degrees. So below 1500rpm and -5psi will be 10's.... Open Idle/ Advanced idle/Templates change these values.
Idle park target=48%
Idle feedback minimum= -5%
Idle feedback maximum= 5%
Idle feedback rate= 588
Idle extra <12 volt= 0

Open Idle/Advanced idle/Ign vs idle rpm table/Table Use these values.
-325 to -125= 10
-100=9.84
-75=8.44
-50=6.33
-25=4.22
0= 0
25= -3.52
50= -5.98
75= -6.68
100 to 300= -8

note: Im not sure if all of the above settings will work for evo 9. Someone will have to test them out.

If you reopen the Ign vs idle rpm graph you will notice is has some steep curves now. This is what makes the engine idle at a steady rpm. The base ignition timing
is now 10 degrees but when the engine idles up it will retard timing and idles down it will advance the timing. This way the ignition timing can control the idle rpm instead of just using the iac motor. This gives a great idle. A/c on, hot, cold high,low,turning, everything. This also fixes some cold start issues. If the engine goes to stall the timing will ramp up and rev the engine back up before it stalls.
this reaction happens MUCH faster then the iac motor could ever respond.

Start the engine and let the idle settle, you should notice the ignition timing moving around alot. More with big cams i would think. Mine moves from 2-18 degrees at idle. But now you should have a rock solid 1200rpm idle.
Go back to the idle target table and move the 150F-248F to 1100 rpm and see how it idles also making sure the idle feedback is near 0.
-3 to +2 is ok. It will be best if you can keep it between 0&-2 as it will encourage a higher idle before the feedback responds.
Now try 1000rpm. 900rpm,ect unitl you find the sweet spot that your happy with.
With big cams i wouldnt go lower than 1000rpm. Mine will idle at 800rpm but its very rough and shaking the car. 1050rpm feels good on my car.
Now open the 02 feedback table and set the idle & drivability area's to 14.7AFR and turn the 02 feedback on.

I hope this helps all you self tuners out there like me.

Thanks for all the great information. I will definitely have to give this a shot when I bring the Evo out of storage.

great write up and contribution to the forum. I have decent idle, but i'll definately try and compare this to my current settings to see if I can improve it!!

Fantastic. I will be testing all of this tomorrow. Thanks.

Interesting theory.

Thanks, it took a while to write it all up. Like 2.5 hours. I tried as best i could in explaining it with confusing anyone. If their is anything i missed let me know. Also, let me know how this works out for you guys.

1 thing to add, after you get it idling correctly and you target rpm setup make sure you go back and smooth everything out. Using the graphs instead of the tables helps alot!

Whenever I adjust TPS I always do it manually and I suspected your findings would be like this.

Great job on the write up I know it will help many people in the future! {thumbup}

I see this is finding its way to the bottom.... How can we make this a sticky??
This is must have info for AEM users.

Yes this is great info. Really helped a lot.

My idle is still not steady with this info I am getting close. So I think 02 feedback also has a huge part to play in your idle. The biggest thing I still get is the car will be idling pretty well and then all of a sudden it will just shut off. As with any AEM you have to find the right combo for your car.

02 feedback doesnt matter much as long as you fuel table is correct boz. Verify that the ignition timing ramps up fast when the engine drops below target idle. If it does not then you do not have the ign vs target table setup correctly.

Ok, so after doing everything in the book to get my car to idle well, I decided to go back to the start and work from there. Well when I first put the triggerdisc ont he car, I had by borther help me with the base timing. It seems that there was a rock chip on my crank pully that he though was the timing mark. So my car was advanced about 15*. So I took some whiteout and hit the timing mark which was black, so now we could really see it. Got the cars base timing all dialed in and now the car idles super smooth all the way down to 875rpm, any lower and the correction just maxes out. So Over the weekend, I will adjust the BISS to get the idle down to 700rpm.

So if you are having wierd issues, go back and recheck everything. Start with all the sensors, and recheck that base ignition timing.

just to help... the IGN vs Target or whatever its called... the table in the drop menu for advance idle.
Anyways, i had an issue w/ idle hunting on a large intake manifold, 75mm tbody, cams, oversized valves/ported head etc...
Adjusting everything else did little to correct the problem... guess what finally fixed it?
That table... i previously had this table in a linear graph which i simply had it calculate from -10deg to +10deg when its correcting too high or too low rpm from the target. Well watching it live on the aem I could see that it was swinging from left to right all the way from one end of the graph to the other. Basically it was telling me it needed at least 8deg of timing -/+ to correct a 200-300rpm drop/climb. The fact that it needed to go across the entire table to do so was making the idle hunt up/down. Meaning by the time it hit the timing it needed to correct itself, it needed it to go the other way and was correcting too late.
So instead of a linear line from those two point... i brought the -8/+8 deg timing closer to the zero axis point so it immediately hit it. I knew it was working because the closer i brought it to zero the quicker the back/forth it was moving and the cell movement was getting shorter. Then eventually the closer to zero it was a stable idle at 1100rpm. Then i just leveled it out to -/+10deg correction and flattened it out on both sides to the 200-300rpm limits on the table. So it looks like a backwards "S" ? lol...

^^^ Ding, ding, ding!!! We have a winner! Thats exactly how i fixed mine. This is what i meant about "getting agressive" with the ign vs target table.

Boz, glad you got it worked out man. I knew there was something else up when you said these settings didnt work. Your on the right track now though.....

ya the car is just amazing now. The idle is rock solid, all of these settings really helped. The other big one that helps a lot is the idle feed back rate. I also found that at about 14.5afr the car was very stable, but if I set the afr to about ~14.8 it would be a little more unstable.

Yes, the base maps idle feedback rate is too fast. I halfed mine i think. This way the ign vs target table has most control of the idle rpm. It will actually idle best around 13.5afr but the spark plugs wont last long at that afr. 14.5 would be fine though. {thumbup}

yes... great write up. this will me a lot.


Good job....

Car is now idling at 900rpm +/- 15rpm. Super solid and steady any temp, any AIT. I have been slowly making my way down, really dialing in each 100rpms.

Best idle thread ever :).

So how do we get a sticky for this thread?!?!?!?

I wouldn't worry too much about this getting buried. There aren't usually a whole lot of post in the AEM section. Although it would be nice for this to be a sticky.

I've got it bookmarked in my browser so I never lose it. {thumbup}

{thumbup} subscribing... this should be a sticky...!!!{thumbup}

This is brilliant. Thanks so much for this write up. I used it to tune the idle on my 91 Supra with 750 cc injectors and GT35R turbo. My idle is rock solid now. I've been fighting stalling issues and messing with the idle settings on the AEM EMS for two summers now. I spent 45 minutes working with your instructions and it totally fixed all my problems. Thanks again.

^^ BAM! 1 more AEM with correct idle!{thumbup} Glad i could help.

Spent some time on another evo IX with this last night. Decent results. Needs a bit more time. But I could tell this is on the right path.

Did the procedure now ac compressor clicks on and off really quick and it wants to stall.it was working fine before.

Out of curiosity, should the values for 75 and 100 to 300 actually be negative or do they switch to positive at those breakpoints?

YES!!! Sorry guys i must have been getting sleepy and i slipped......:updown:

NOTE: The ignition offset values in my original post have ben corrected. Thanks Masternater!

Gordian, Make sure you have the tps sensor setup as i described in the first post.
If the engine wants to stall when the compressor comes on raise the "ac clamp load" % until when the compressor comes on, the rpm does no drop below your target idle rpm.

getting my AEM tomorow.... ill deff be trying this

Ignition offset curve helps, but fine tuning the duty feedback table makes a huge difference. Set the target idle at 500 rpms and watch the idle feedback correction %. Add or subtract that % to your idle base duty table at that particular rpm point. Increase the target idle rpm by 100 and retest. Continue until around 2,000 rpms. This will make feedback about perfect.

^^^ Correct! It is actually best to have a idle feedback # in the negative, meaning the ecu is taking away IAC duty cycle. This encourages a higher idle when the throttle is released to help prevent stalling. Works very well with big cams and a low idle where stalling seems to be the biggest problem.

AMAZING summary. Very impressed. +1

Browningderek, I want to say thanks for your thread, I also have a HTA86 with e85 and 1600 cc bosch injectors in an EVO9. My idle was not good and following your suggestions I was able to fix it. AEM instructions suck.
I had a rough time trying not to leave the tps % in 0, finally I got .8%,
also I left the Idle feedback minimum= -10% and Idle feedback maximum= 15%, still trying to understand everything you wrote , Im not a tuner , thanks again for your thread.

No problem guys! glad this helps.

Very HELPFUL thansks so much for the writieup

I got the idle ok, now my off idle low speed is lean , I will try to correct, very helpful post, thanks again!!

Check your fuel decel settings. after you got the tps corrected it might have to been changed.
I always try to find the lowest "fuel decel tps %" i can and the decel still work. Around 2% should be close.

You did good work sir! This should help alot of AEM users out there!:beer:

also wanted to add regarding the decel issues for some... on the AEM series2 boxes / aemtuner, you MAY run into the same problems i did. All of the idle help on this page works... but when i switched over to the series2 box i had an awful idle hunt and stalling issues. Spent a week or two working it over w/ all these tips like i did w/ the older series1 box to no avail. Turns out the FUEL OFF RPM was set too low from AEM. It was set at 1500rpm. I raised it to 1900rpm and the stalling/hunting went away. The IAC duty% started to finally work as well. I suspect it was fighting the FUEL OFF situation due to the rpm range too low? Btw you can also set the vacuum range when fuel goes off on decel(FUEL OFF LOAD) as well. I have mine set at -8psi vac. Its 2psi lower than the lowest idle vac, so should only kick on when the vacuum is really low on decel. This feature shuts off the injectors during decel, i think when its set too low the idle functions have no fuel and therefore either stall out or hunt because its trying its best to keep it alive w/ no fuel. I believe when i raised it, it allowed the idle rpm range to revert back to the fuel map and allow the idle functions to work properly. Anyways... in case any of you had similar issues.

thanks for the write up

what value do you guys have your "Idle FB Rate" set at? What would be ideal for big cams to help set idle?

Question. Is the lowest idle you can run with EMS 1200 rpms?

Nope; you can set your idle target where ever you wish.

Oh, thank you. I just saw the scale of numbers in the OP and drew my conclusion from that.

Its in the OP. 588ms

Hello there, this is an awesome thread!!

What about people that are running without an ISC motor?

Would there best friends would be BISS, Ign Vs. Idle Rpm, and Base Map??

Also do i have to worry about the Idle Learned Value when running without the ISC? Thank you

Yes, if not running an iac you will have to turn the iac controlls off. Why would you run without an iac anyway?

Sub'd. Not really having any idling issues... but interested to take some of the concepts and see if I can make it even better with the trims. Thanks!

I've had this thread on my bookmark for a long time, I had some stalling issues. Im no tuner but wanted to get rid of the embarrassing stalling at lights! Well it turns out the original tuner did not do an idle adjust after the 280 cams were installed and after warm up the car would stall, so after a little reading I adjusted the idle table to give me an extra 200rpm to hit 1100, so no more stalling, Thanks!

Now my new problem, my evo has a "Prius" complex! After start up, it idles at 1,100rpm but after I hit the throttle it jumps to 3krpm and wont come down unless I load the engine with a gear engaged. The RPM drops and then it idles back at 1,100rpm. But the cycle repeats itself, even when driving on the highway it works as a cruise control!

Any info would be greatly appreciated.

Vic

^ this is a late response but if your willing to post your calibration map, i can take a look as i'm sure others can also.

I don't know how I missed this either, but it sounds like his fuel decel cut isn't set properly. at that high of RPM, the fuel should be off.

I'd also like to add to the discussion: I was having some problems with my A/C killing my car. The idle Comp was set properly, I had 0% feedback with it on or off. But when the compressor would kick off the car would stall.

What I noticed was that when it turned off the feedback would yank down to -5% super and overshoot the A/C off target, causing the car to stumble. I tried adjusting the Idle FB rate, but it didn't really help. I ended up just turning the negative feedback limit to zero and it completely cured it, with no ill effects to my overall driveability.

Sounds like you are just covering up the main issue. Try setting your a/c comp & delay higher. This way the engine will rev up before the compressor comes on. When the compressor is on it would be fine if your feedback is -1 to -3 after the idle settles.

Pirana, sounds like your tps sensor is not setup or working correctly. When the throttle is near 0% the fuel cut rpm limit is 2000rpm so if your engine idles higher than that i would check for a sticking throttle or a tps thats not working/setup correctly.

Also, if your having issues it helps ALOT if you would post your calibration.

It's not when the compressor kicks in, it bumps up just fine. The comp is dialed in perfectly, and the delay is such that it barely fluctuates RPM. It's when it kicks back off. The RPM will jump up a bit, The IAC is set to say, 45% with the A/C on, 20% with it off. with the bump in idle, (maybe 100rpm) it will overcompensate down to 15 to bring the RPM back down, but it won't recover fast enough to the 20% that it SHOULD be at when it hits 900rpm, causing the car to die.

I know it's kinda confusing, but it's like if you're in a plane, and you're cargo gets dumped, it's gonna rise slightly... well with the negative correction on there it's like the pilot jamming the stick down to compensate, but too aggressively, thereby undershooting the desired altitude and hitting the ground.

I'm open to other ways to keep it from doing it, I just haven't run into the need for negative correction.

instead of trying to describe it, post a f6 style log with the appropriate channels logged, so everyone can see whats actually happening.

my a/c load comp is set to 2.73%...... your running 25%???

So It dies when the compressor turns off? Like aby said, 25% clamp load is huge! I usually see between 3-6%. You may want to get readjust your biss screw on the throttle body. IMO the iac valve is most effective between 30-50% duty. So if your idle duty is only 20% then idle it down on the throttle body so at 30% duty the feedback is 0 to -2.

On another note altogether, what year is your car and have you ever replaced the iaccoca's valve. I just had my stock one go out. $330 for a new one! I almost had a heart attack... lol

Yes, it dies when it turns off, I was using 25% as an example, I think it's closer to 10% I'll have to go look.

I set the BISS to the factory settings (I'm on stock cams at the moment) but I'll try readjusting it to get the IAC up more. I think at 900 it's at ~10%

I've got it apart at the moment chasing down some boost leaks that I think are causing an entirely different issue, but when I get it back up I'll get a log of it.

btw, mines an 03, and luckily I've never had to replace it... methinks I'd be swapping to a q45 TB, or at least junk yard diving for a cross-referenced part, before I popped that much down for the IACV!!

I saw a complete tb with iac in the for sale section for $90.

Sub'd

Great info shared! Thanks

This may be off topic on this thread but can someone tell me how to check my tps settings or values or percentages on the aem pro software. i had to re calculate my tps but i know nothing about the software and afraid of messing something up

Cold/Initial Idle
 

I did all this and when warm it works great :) Thanks so much for the write up! I have a bit of an oddity though, when the car cranks and starts to idle when cold it doesn't use the correct target RPM :( I started the car this morning and it was cold idling around 800 RPM hunted and then died. So pull out the laptop hook it up and try again, looking at the Idle target base table, clicked follow ECU and based on the coolant temp at the time it should have been idling around 1300 to 1325. Any idea on where I should look for the problem?

Cold start issues with a properly set idle are usually fuel related. What kind of AFR's are you seeing at 800 rpms before it dies?

It was really lean. There was a hole in my fuel map right where it wanted to idle, I fixed it and made it more stable, as in it no longer just dies, but it's still trying to idle at 800 when it should be at ~1300. The AFR's I'm getting when driving cold are still leaner than when I'm warm. Is this by chance something to do with warmup enrichment? I'm just guessing tho...I can log it later when I cold start it after work today. Anything in particular I should be logging beyond AFR, Engine Speed, etc?

Okay my laptop decided to take a dump all over itself yesterday :/ No logs til I fix it. Hopefully I'll be finished by this afternoon.

thanks for the post, I am in the process of tuning the car and that really helped me a lot!! Car is idling pretty good. I am stock now on the O2 FB, you say to set the table to 14.7 on the idle cells. Im I in the correct table? If so, they look pretty off! Any suggestions, thanks!!

http://i161.photobucket.com/albums/t...pse90b62c6.png

It looks like your load breakpoints are off. I like to use psi instead of kpa. It's more relatible for me.

Is an AEM v1 I don't know how to change it.

i tried to do as the O/P said. but i am not sure if i did it correctly. how does this graph look compared to anyone elses? does it appear i did it correctly?

Attachment 273854

Nice

Anyone still watching this thread? I have idle issues, my car apparently has had 1000's spent but my idle learned value is always in the red 14% plus car does idle but doesnt do what it is supposed to do. It is on a series 2 ECU running latest firmware and latest tuner software. Could set up teamview or something for someone to have a look :-)

Thanks

There is a Youtube series specifically for the AEM V2 by "Jonathan Fasking" I believe, where he goes through the full setup and tuning of the device. You may try that.
I know that if your fueling isn't very good, you'll have trouble everywhere else.

If anyone is going to be able to help, a detailed info on current setup would be needed.

Jonathan Fasking U-Tube training series on AEM EMS is an awesome resource. 16 Videos in total. I am an EFI University Certified Tuner and have attended AEM advanced course training and AEM V2 specific training and his videos are spot on. Sub'd for future ref.

Old thread but this info was very useful so I figured I would ask here. My Evo was stored for many years and ran great on an AEM v1. Took the car out and went over nut & bolt and finally fired it back up. It is a little tough to start when cold and the idle would surge from 900-2300 which led me to this thread. it otherwise is running well on the previous tune, After adjusting these settings I got the car to idle smoothly at 1200 when up to temp but when I blip the throttle it hangs and sits around 2000 when off throttle pretty much indefinitely. I'm thinking there is an enrichment somewhere that isn't tapering with temp or RPM somewhere?

It is also seems to catch faster when starting, but stumbles at 800 for a few seconds then surges to 2000 before settling to 1200 after ~10s. The injector all checkbox is on and the crank timing is 10 deg. I figure this was affected by the idle settings.

I know this place is pretty dead but hopefully someone with more experience than me can chime in.
Thanks,
Bill

Hey Bill. With your laptop connected and AEMPro running, go to your main Idle page. Make sure the Parameters window is active, and then press F6 to start logging. Blip the throttle to get the idle to surge and hang. Then, press F6 to stop logging. Email me the log and your calibration files to EvolutionNate@gmail.com. I'll take a look and see if I see anything out of the ordinary.

Nathan