turbo 2zz - unstable idling :(

[X-axis]

Today i was going to do some tuning of my PowerFC on streets. Started car and idling was okay without any problem.
Done some inj/ign map revisions successfully; tuned for no knock, good AFR and EGT. But than my car started to pulse RPM at idle, about 800-1100 RPM. Sometimes even 500-2000 RPM and engine is about to stall.
At this moment AFR can jump from 10:1 to 18:1 and fuel tuning for this idle cells doesn't help at all :(

And one more issue about this, i think it happens from the same reason - if i'm running at 1st gear at about 1500 rpm not touching the throttle, car begins to shake (how if i quickly press and release throttle).

Here is short video i made some minutes ago at parking http://www.youtube.com/watch?v=UmDVNjoQrh0
Idle RPM jumps near 800-1000 and AFR from normal to lean. :shrugs:

[bt216]

what happens when you rev it to 2k?

[enjoi4586]

Did you ensure that your car learned idle properly on first startup? If not, your going to have to re-initialize.

[bt216]

if you rev to 2-3k and it seems fine then its probably just because of the idle. that would be normal.

[enjoi4586]

that would be normal.

How would that in any way be normal? I have crower stage 2 1/2 cams and my idle is rock solid with and without a/c at 1,200 RPM.

I'm telling you dude, you need to re-initialize your PowerFC and go through the idle learn process again (assuming you did it to begin with). Just remember that when you re-initialize it, it erases everything. So back up your map before hand, re-initialize, load your map, and then go ahead with the initial process.

[enjoi4586]

Another thought is that you have your idle and fuel cut too close together. That would also cause your idle to fluctuate like that.

[X-axis]

Re-initialized my PowerFC, loaded map and go through all 30 min learning process. But id doestn't help at all, nothing changed.
Hers one more video of idling 500-1500 (it offen happens when turn on/off blower/ac) and i think it can't be normal http://www.youtube.com/watch?v=rbdvA6VGQR8

Here is charts of unstable 800-1100 idling
http://img160.imageshack.us/img160/9260/chartsjy9.jpg

enjoi4586, fuel cut - what do you mean? F/C A/E and F/C A/C settings?
http://img160.imageshack.us/img160/4415/set1wh1.jpg

[Boosted2.0]

Your timing and fueling is too inconsistent between load cells. Post your fuel and ignition maps and highlight the cells that are getting hit at idle.

You can easily see that your RPM and timing are changing exactly with eachother - thats a sign of too drastic a transition between cells.

[X-axis]

Yes, fueling between load cells differ in 1.5-3 times

Here is screenshots, i highlighted cells which is used at idle. The darkest ones is used more often than other

http://img216.imageshack.us/img216/6782/baserd0.jpg

http://img229.imageshack.us/img229/9039/ignkt1.jpg

[Boosted2.0]

Save that map and make all the ignition the same for 800, 1100 and 1500 and load 1200 1600 and 2000 and increase your fuel a bunch in the 1200 load row

[Jesse IL]

Read the sticky. Your idle settings are wrong.

[X-axis]

I used your sticky manual to tune car, its great!
May be i understood something wrong because my english is not so good? :(

[Jesse IL]

Never mind on the idle settings. You're not hitting the fuel cut so you aren't getting a surge because of that.

I'd say you have a vacuum leak. You're running very lean at idle, the idle is getting up to 1100 rpm, then the ECU is chopping ignition timing to try and compensate. Set ignition timing to 20 degrees in all idle cells. Initialize the PFC and turn idle ignition control off. Adjust your fueling until you get a stable idle.

Another possibility is that your IAC is stuck open.

[X-axis]

Can i detect vacuum leaks by my boost gauge?

[Jesse IL]

No.

Try raising all your fuel cut values by 200 rpm and see if the idle stabilizes. From what I can tell, your car refuses to hold a 1000 rpm idle for some reason. You can try pulling the plug on the IAC and see what happens. That should give you maximum closed throttle, and by controlling ignition tming and fuel, you should be able to get a very low idle. If you can't, either your IAC is stuck or you have a vacuum leak.

You could also try putting in the stock ECU and injectors. It will run fine at idle and if there are any vacuum leaks, you'll throw a code. Stuck IAC may or may not throw a code, as I'm not sure if the ECU recognizes a fault if the car won't idle down.

[X-axis]

IAC valve looks to work okay.
I put values 20 in this cells at IGN map and around "1,000" in 1200 load row at fuel map and all problems with idling were solved. Car idling is stable and AFR is about 14-15.
Thanks for help!

P.S. At WOT runs i got EGT up to 830 C (1550 F), is it normal for stock internals? May be i need to add some ignition advance to map for lowering EGT?

[X-axis]

What about EGT? Anyone have EGT gauge with turbo?

[steveox]

Your EGTs look similar to mine.