I notice when my idle drops and stall saver kicks in the IAC seems to open too much. I believe this contributes to an idle surge. If I set idle with TSS it is much better. Can I reduce the number of steps of IAC with use of above?
Likewise would high step delay also be of help? Or is the gain breakpoint used as well? This is a gm 7.4L tb with 350cid.

 

All calibration parameters in the EBL are programmable. You can set these to what ever works. Although, I would first figure out why the stall saver is being invoked and fix that first.

RBob.

 

Idle is more stable since I advanced the TSS a tad. This is what I have:

Op LD set open loop idle
IDSA set I assume idle SA set/locked
IAC idle speed 700 rpms
Idle state SA 17 deg
idle speed drive 712 rpms
" " park 712 rpms
IAC stall saver exit 625 enter 550(no longer effective since I moved TSS inward)

data analysis shows idle moving 750 to 800 rpms with sPW moving 2.1 to 2.0,
Map 45 to 43, IAC not moving at 22. No stall saver since I advanced the TSS. Yet idle moving. SA moves 16d to 15d.

I thought I had SA locked in .bin? Possible slop in dist bushings? Wont that move idle?

 

The IAC at 22 steps on a warm idle is still a little high. On TBI systems I shoot for 5 - 10 steps at idle. Warm engine, no additional loads (A/C, headlights, fan, etc.). I would open the TSS a tad at a time until the IAC settles in the 5 - 10 step range.

The SA can move around from the idle compensation SA. This is idle stabilization logic. Basically, if the idle drops a little SA is added. If the idle picks up, SA is removed. With a timing light it looks like SA jitter, but it isn't.

The more the engine is modified the less the SA corrections need to be.

RBob.

 

Thanks again. Last season I was 100% on idleing on TSS with zero steps IAC. This spring I decided to reapporoach IAC control and this is what is happening. This morning it seemed a lot better. I have not yet inspected log. I did reduce idle compensation SA previously. I will compare to EBL.bin and reduce more. What I did see this morning with intake full heat sunk was a very good idle when at 13.5/1 on WB. When idle dropped slightly under commanded the A/F went to 16-17/1. I did add some fuel in VE to oversome that but was unsuccessful. I will change the A/F in OL/vac/rpm table at lower RPMs as maybe that is the answer rather than VE?