Well Doc's still chuckling over this one.

Just as a FWIW.

I've been chasing down an ocassional stall. Usually on a hot restart. You could watch the IAC retract, the AFR go lean, and then the stall.

Idled as smooth as could be, just the ocassional stall.

Fussed, and fussed, and fussed, and fussed around with it.

Well, in the last 3 days, have gotten *about* rid of it. Actually it's gone, but just playing with some stuff.


And as a FWIW as what might make an engine happy.

An IAC max count of 25.
Idle speed timing correction limits of 7d even for a 50 RPM error.
Artifically low commanded idle speeds.
2-4% more VE at idle.
13.2 AFR at idle.

YMMV

 

So if the idle is higher than your low commanded the code will pull 7 degrees of timing to try and get it to idle? Also the richer idle makes sence, what was it before?
Also, did you have to raise the min idle mechanically for IAC idle steps at zero? Sorry for lots of questions but I've done a lot of what you've done to get my engine to idle like glass.
I've been maxing my IAC steps for a while now just to keep stall saver and mild highway/cruising assistance but when I lift I like for the engine to come down (emissions WHAT).
I found my engine to idle best when the IAC was at zero, slightly rich (more stable after quick decel at a light), and the desired idle was too low for the computer to reach resulting in some timing being taken out but always a "high idle" flag set. I tried it the other way but it never ran nearly as good. The only problem I'm having now is that when I go into neutral or park from this "high idle" the engine will surge up sometimes as high as 1500rpm and then take a while coming down. I've left it for now because it's not a big deal but I'd like to get rid of that. After thinking about it now I bet is has something to do with running rich at idle and having the timing increase with lower MAP (going from in gear to neutral), I'll try and lower the timing and lean it out a hint to see if I eliminate that surge .

 

It will add up to 7d. You can see the timing move around, as it hunts, just the the IAC counts, but faster.

At 0 it was always nice, it was the hot restarts, and prolonged idling that were the real problems.

0 always been best for me.

Might limit the max IAC count to get rid of such a high *idle*

Until the Quick Start install, 35 was the lower limit on the IAC, or starting become a real issue. I wasn't sure it would even start this am at 25 but it was like as normal.

 

How are you guys richening the idle? Running in open loop? Or adjusting the global stoich value?

 

I'm running open loop and closed loop, depends on the day and what I'm trying to accomplish. Closed loop for long trips, open loop for short cruises near home.
Bruce, I have the max IAC steps at 96, it's been that way for a year now. The steps near idle never go over 25, desired is 650rpm and timing is abmormally high I think (that's in my main spark table). As for idle timing, I haven't really watched where and what it does only that it never +/- more than 4 from the cell in the main SA table.
I should clear it up, the idle surges to 1400/1500rpm when hot and then hang there for a few seconds, then immediatly start coming down (slowely) to desired.
That is all in open loop. In closed loop it does the same thing except it'll idle rich (o2 prop gain and duration adjustments where the sensor will stay richer more than lean).

 

wrong button....sorry, should be a new post

I've been thinking of tuning my car / VE table in Open loop just to be able to get the A/F I want at diff situations ex. lean crusie. My WB shows 14.3 at cruise now in closed loop.....

I know one way is to raise "min temp to closed loop" but then I always will be in Open loop.

What happens if I set MAX BLM value to 129 and then lower my VE table at cruise to get a higher A/F value? This way you could force the A/F to be leaner?



/N.

 

What's the IAC count when that occurs?.

 

It's a balance of commanded Stoich, min O2, max O2, that sets the 14.7.

Varies with code, but you might wind up with code 44s problems.

Play with it see what happpens.

 

I will use the $58code (as soon as I have all the parts, getting closer... )

/N.