High Idle at start up.

[95solster]

ok so 1999 DBC 5.3L shorty headers 2002 25.2 Lb injectors.

so it first ran on the 1999 PCM after it was adjusted a Bit.

Due to some limitations I upgraded to a 411 PCM. The 411 PCM was from a 2002 Tahoe with a 4.8L automatic

I did a segment swap to correct the 4.8L to a 5.3L and then again to make it a manual.

The old 1999 PCM the truck would start and run just fine.

The New PCM the truck starts but at first it stumbles ten seems to stabilizes but the rpm's rise to about 1900 the will drop down to 900 the idle normal.
it does this both cold and hot starting. (Tune File: 2002 Chevy Step 3.hpt)

2002 Chevy Step 3.hpt

I made some changes to the Idle RPM and Airflow setting and now it starts without the stumble but RPM jumps to 1500 then creeps up to 1900
and Drops to 900 and idles normally after this happens at every start up. (Tune File: 2002 Chevy Step 4.hpt)

2002 Chevy Step 4.hpt

Just looking to get it to Idle without the jump to 1900 RPM.

I have searched but everything I find is for Bigger Cams or the Gen4 LS engines

[lukearmstrong1990]

start up off idle scaler, try changing from your value of 1 to 0.
try setting underspeed time below this to 0 instead of your value 3.0
0 the frictional airflow decay
reduce the frictional airflow initial table by 30% to begin
o stall saver in gear table
increase your start up spark flare control multiplier for warmer ECT even up to 1.0

[95solster]

didn't seem to fix it