I decided I was sick of how my car was idling after the cams so I took the 10 minutes to try out a few different settings..The graphs may not really show but it actually idles nice and steady now instead of jumping around like it used to. Before it would stumble and surge to 1200 and then settle and repeat..Now it's just a nice steady lopey idle..Much better..
Here are the befor and after logs..
Before:



after:



Timing now sits around 11-14 degrees at idle instead of 5 to 9 degrees. I also had to add a bit of fuel to get these results.

 

BTW the cams are GSC S1 on an evo8..

 

Just so you know, unless you are running open loop for idle, adding fuel at idle won't do anything. Closed loop fuel control, such as idle, is controlled by the ECU to be stoich (14.7:1). The only way idle wouldn't be stoich is if you were maxing out your fuel trims or running open loop and using the fuel maps for your target AFR.


Eric

 

I did not know that, I guess I will change the fuel setting back to how they were then..Thanks for the tip..
The car idles 10 times better with the timing advance though..

 

Yup, timing advance at idle goes a long way for smoothing cams with the stock ecu. Sometimes too much can trip P0300's though.

 

Big jump from 5 to 11???

 

What I do for anything up to 272's is add timing (8-9*) and then go to the idle table and bump the idle a couple hundred rpm till it idles at 850-900. If it still doesnt want to play ball I will add some to the ISC steps for AC off neutral as well.

 

I guess the fuel will increase by default as the car is trying to obtain 14.7 afr?

Would you change the timing from 0 load to 40 load, and from 0 to 1250 rpm?

850 idle would be ideal IMHO.

 

Oracle, yeah more or less thats it. I think I only bother with 0-30 and up to 1500 (I scaled out 1250 long ago). Desired idle neutral I will bump to 898 I think the value comes up as, sometimes a little higher, in the 50*C and up area and it mostly smooths out. I did one for a kid this past weekend and he didnt think it was smooth enough (whatever thats sposed to mean) so I set it for a 1000 and it idled fairly well.

You can make it idle in open loop if you adjust both the open loop load table and the open loop throttle tables (#1 in both cases). Drop the value to 10% and then alter the fueling as you need. That in itself is a subject for an entirely different thread however.

 

Just a thought, would increasing mivec map at idle (500) range from 0 to Eg. 4.8/9.6 help smooth out idle too?

 

No increasing cam advance at an idle makes it lumpier actually.

 

JohnBradley,

So you're saying to up the value in the 50* in the Desired Idle RPM Neutral to 898 and add some timing and the car should idle better?

What map are you suggesting the timing settings be changed in and what settings are you referring to?

Thanks for posting the info.

 

Would increasing the timing upset the Fuel Trims?