Thread: Tuning for S3 Cams (idle correction)

Can someone point me in the right direction on this, I would like the idle to be stock or as close to as possible. I have read that JWT has made timing and fuel changes to accomplish this and its more timing changes than fuel.

Its an Auto else I wouldnt have cared and its S3R cams specifically, don't know if that matters or if S3(M) and S3R have the same effective profile and so the same fix.

any assistance here would be welcome.

nothing? some ideas? rumours of fixes?

There is an idle speed table in the bin file that defines idle speed as a function of engine temperature. JWT changes this table to increase the idle speed to 950 RPM at normal operating temperatures for their S3/S4 cam tune. They also alter a timing idle adjust table that is used by the ECU to "push" the idle speed toward the RPM specified in the other table when it deviates from that spec. They change all those values to "0". I personally do not find this second change to be useful.

It's not clear from your post what ECU you are running now or what your idle is now. But if you want to mimic these changes, you will need to be able to re-program your ECU. Also, since you are running an automatic, you should be aware that the ECU for a 5-speed will not work well with the auto, even if you use the auto bin files. There are other differences that matter, so you should stick with an auto ECU.

You can also set the idle timing to 19 or 20. It is in a separate tables referenced to temp one table for in gear and another for out of gear. You only need to change the settings in the normal range. I did find that the timing retard set to 0 helped.

Warning, if you change the idle timing you need to use whatever value you put in there when you set your base timing not 15 degrees.

At best it still won't idle like stock but should be sort of stable.

Does this mean that you would need to pull 4*-5* of advance across the whole timing map to adjust to the higher base timing setting?

No. The ecu locks the timing to whatever you set the idle timing to. It is just a place to sycronize the distributor to the ecu. If you have already set the base timing at 15 and you change the ecu to say 19 it will still be set at the right place. The idle timing table is where the ecu gets the value to lock the timing to, 15 is not some magic value it is just the idle timing value which is 15 in the stock ecu.

ah hah

The ecu is a JDM P11, would require a nistune type 4, its one with a 20 x 30 header on the board

I am not sure if I have these tables defined so will have too do some looking but at least it gives me a starting point, I should be able to revert to a B13 type ecu if all else fails but if an idle speed of 950 is central to a smooth idle I dont think that is going to work well with an auto, my starting point is a Mines tuned ecu that was meant for an auto. So it controls the lockup solenoid and whatever else I guess.

Idle in neutral is around 800 and in "D" is around 730~750 ish except when it lopes which is not really consistent its like an ocassional miss.

thanks guys I will give that a shot.

i have idle issues real bad wit s3 cams it never lopes

it idels at 2 grand or 800 with no lope but it use to