Another Idle tuning question

[billyjo]

I've done a lot of searching and reading about how to tune for idle. I've read about steps, reseting the TPS, adjusting the screw, and logging RAFIG but right at the end I discovered (or at least I think I did) that these are all for cable throttle bodies and not ETC.

Does all of this apply to ETC as well? What are the proper steps one should follow to make sure all is well in the idle department when using ETC?

I'm running a 2002 custom operating system 3 with a LS2 ETC and I have a manual transmission. With the key on (not running) my TPS is 19.2%. When it's cold (the colder the worse) there is quite a hesitation at idle, this goes away when it's warm. I've been able to smooth this out by increasing A0008 to 1.11 but I'm not sure that this isn't just offsetting a problem?

Another problem I have is after I load a new tune that once it's warmed up when I come to a stop it's searching for idle. Once it's done this 4-5 times it's fine (I understand it's learning). I thought logging the RAFIG would fix this but it didn't.

Any help is greatly appreciated.

Bill

[dfe1]

ETC systems don't have an IAC, so idle speed is controlled by throttle position. IAC posiiton with key on engine not running typically is at or near wide open so there's plenty of air available at engine start. Your 19% TPS, is the equivalent of an IAC being at or near wide open.

Logging RAFIG won't fix anything, but it will give you an insight into what you need to change to eliminate idle problems. If that doesn't work for you, look at idle air flow right after you load a new tune and after idle stabilizes. Then you can make the changes you need.

[billyjo]

Thanks for the info dfe1 I'm going to give that a try this weekend.

I'm still working on the hesitation when it's cold, and it's definately temp related (outside temp). I noticed yesterday while watching the wideband that it goes very lean when I let off the gas to shift when it's cold out. What would be causing it to do this only when the temp and engine are cold?

Thanks,

Bill