high startup rpm

**bonnieclyde100** · 10-17-2014

my idle rpm is already set a little high because of my engine setup but i need to adjust my startup rpm. when i start my truck the rpm shoots up pretty high and then comes back down and now its getting colder and it is going even higher than during the summer. do i adjust the table named IAC% flow vs. temperature (P/N) to bring it down some ?

**ony** · 10-18-2014

what ecm are you using?

**bonnieclyde100** · 10-18-2014

i have a 16168625 with a $oD bin modified BJYL .

Originally Posted by ony

what ecm are you using?

**ony** · 10-18-2014

I am not up on the 625's ,sure someone will give some advise.

**sturgillbd** · 10-18-2014

I can probably help you. If you want, post your bin and I can take a look at it this evening

**brian617** · 10-18-2014

Seems like I had same issue especially when temps cooled off. Best I can remember I reduced start up spark advance. Watch your spark advance at start while connected to tunerpro. Believe happens when you heavily modify the stock timing tables. I cut the spark added figures in half.

**bonnieclyde100** · 10-18-2014

Originally Posted by sturgillbd

I can probably help you. If you want, post your bin and I can take a look at it this evening

here it is. just a little about my setup i have a frankenbody which is a four barrel TBI i made from two gm throttle bodies.it already idles between 750-800 .i already lowered the idle rpm timing to try and bring it down more . as far as starup timing i will have to look at that. i was looking at a recording and the IAC started at 150 and quickly came down to about 35 then came down more as it warmed up. i was thinking if i could get it to start at less than 150 that would help.