I am fighting a really bad surging problem with my tune. I have tried changing settings back and forth and am having no luck as I seem to make things worse. If I provide a data log and bin, can someone with some experience point me in the right direction to getting this thing fixed?

 

You need to post engine details to compare what is seen in the bin...

Anyways, I am seeing;

8* Initial Timing in bin (confirm your base timing by hand is 8*).
20* Idle State Timing
350 cubic inch engine
36# injectors

Your SA Main Table is not L98 specific, so be sure to cut and paste the SA Main Table values from bin 3005 found in the EBL P4 file, and paste them to your current bin. If the four details that I shared above corresponds with your current setup, then the SA Main Table swap, as well as a few VE Learns... and you'll then be where you need to be.

 

Engine details:

350 standard bore
Aluminum corvette 113 heads
Comp cam 264/270 and 488/495 lift with 1.6 roller rockers
TPIS miniram with 58mm throttle body
36# injectors
1 5/8" headers

I thought I had the correct timing tables for the aluminum heads. The IAC is what I have been messing with as it goes up and down a lot. I tried to add the data log but this site wont let me share it.

 

The table is fine, but the idle values are off. During your datalog watch where your kpa is hovering in idle, then take that kpa value and look it up on your current SA Main Table, and see what the SA Main Table is commanding in that RPM/kpa area. When you have that value, compare it to the 20* idle state command, and you will see why it is playing tug of war...

 

Joe, just looked at the datalog, your running way too rich. First confirm the base timing by hand is 8* BTDC, because it needs to match the Initial Timing in the bin. Just want to verify that it is indeed correct. Next, the SA Main Table can stay as is because your kpa is low during idle, so don't worry about it. First thing you need to do is lower your fast idle screw on the throttle body, it is showing 2% on the WUD during idle and your RPM is fighting, so back off on the fast idle screw until you see 0% on the WUD. The throttle blades need to be closed, only the IAC itself should be controlling idle air. Once you back off on the fast idle screw on the throttle body, do another VE Learn...

 

Ok I've got it idling good finally. I backed off the idle screw and it read 0 on the WUD. Sometimes it goes back to 1% and I have adjusted it several times and it will still read 1% when its warm. Now, I guess I'll drive it and let it pull fuel out or should I take some out to accelerate this process?

 

Let the VE Learns pull the fuel out for you, shouldn't take more than one to two Learns to get it done. It works rather quickly, and more accurately...