I've got s_aujpV4; pretty much as stock as it came. Car idles quite well for an hour or so....and then it starts surging at idle? Would my IAT have anything to do with that? I know it gets really hot where I'm monitoring.

I don't understand why would idle so well (and be warmed up) but then later start surging....

 

Could be related to the SA RPM error tables trying to over correct once the warmup ocurrs. Try reducing the amouts at the lower error points to limit the spark correction.
Could also try the OL idle setting to see if that helps too.
I run small correction values in the lower cells of both tables and very few IAC counts, idle only varies 50-75 RPM. SA moves only about 4 rather than 6-8 as with stock settings.

 

IDLE SA RETARD VS RPM ERROR (LOC 1EB->1EF)
&
IDLE SA VS RPM ERROR (LOC 1F0->1F4)

Sometimes I don't fully understand the statements in responses so I ask for specifics....just trying to learn.

If the above tables are the ones you meant, how "much" of a change is a good start? I have no feel?

Where would I find the "OL Idle Setting"? I've looked and used the Item Finder function ....

 

992& 993 are the RPM settings for OL Idle.
Keep a 100-150 RPM difference so you don't keep cycling in/out of CL.
993 = 350 Goes into Ol idle, RPM must drop below this.
992 = 500 Goes back to CL (If norm parameters are ready for CL)
We put the values low to disable OL idle by default. Adjust them to be slightly higher than your idle RPM to enable it. Probably not needed for your problem but is there as an option.

I lowered the reaction in the RPM error tables as shown below.
Stock on the AUJP was 4.92* in all cells but zero error
My Retard 1EB table
4.92 --200 rpm error
3.52 --150 rpm error
2.46 --100 rpm error
1.05 --50 rpm error
0.00 --0 rpm error

This table was filled with 4.92* in all cells (Including zero error)
My Advance 1F0 table
4.92 --200 rpm error
3.52 --150 rpm error
2.46 --100 rpm error
1.76 -- 50 rpm error
1.05 -- 0 rpm error

Some guys have gone more extreme on the settings to reduce the spark jumping around at idle. This yeilds me about 4* IIRC and my idle smoothed out a bit. Might do the job to keep the IAC occillation from starting.

 

I made those changes to my BIN, I'll burn a chip and see how it works this weekend.

 

....so, I have another question.

It even surges when I "open" the timing connection to check the timing.

I have a couple of questions:

What rpm is the engine supposed to be turning while the timing ckt is open? Where is that adjusted?

Is there a favorable TPS position? IAC Position?

 

AFAIK you should be at idle setting when disconnecting the bypass on the dizzy. I don't believe you should see much movement in timing unless the RPM is changing or is rough. Could be a little slop in the distributor causing it to rise up/down with power pulses. Just guessing though.
TPS and IAC don't play any role when in bypass. Once the bypass is hooked back up then TPS low with low IAC steps (under 20) should work.

 

So, IAC steps should be less than 20...that's good to know. I'll adjust the IAC Steps to be <20. Could the knock sensor cause the idle surge? I'm just grasping now. I will also relocate the IAT sensor...gets really hot right now.

 

I'm going to go experiment here shortly (it's a little early to be making a racket outside yet) and I started wondering if fuel pressure could cause the idle-surge?