LQ 9 no idle

[[email protected]]

Looking for some help please. Prior to covid I purchased a rebuit stage 2 LQ9 stand alone package with drive by cable and a 4L65E from a company that has since closed shop. I have finally gotten to the point where I am trying to run it, and I have a issue with getting it to iddle. The only way I can get it to idle is to either feather the throttle or to turn up the the screw to open the throttle plate ( the factiory screw was stuck so i had to drill, tap and thred a screw to open the throttle plate. ) any ideas as to my issue ?

[5FDP]

More details on what this "stage 2 " is because that really means nothing here.

What is done to the engine, camshaft, injectors etc etc?

Is your fuel pressure at 58psi?

I'd return the idle screw back to normal and we'll go from there once we have more information.

[kevin87turbot]

You need to add a significant more airflow to the base running airflow table. I would start by adding 3 gms/sec across the board. If you have a stock TB, open the blade until you get the TPS around 0.65V to start with. I would also increase the idle timing to around 20 degrees to start with.

That's kind of an odd tune. Looks like it's got some airplane gears.

[pinkytuned]

if u need help lmk i can help you just dont know how to send u file back on here

[[email protected]]

Sorry supposed to say stage 2 cam, 224/234 @.050 .612/.638 lift 115? LSA everything else is basically stock. 317 heads. Yes fuel pressure is good. If I turn screw back, it wont idle. Drive by cable computer is 01 GMC 2500

[[email protected]]

You need to add a significant more airflow to the base running airflow table. I would start by adding 3 gms/sec across the board. If you have a stock TB, open the blade until you get the TPS around 0.65V to start with. I would also increase the idle timing to around 20 degrees to start with.

That's kind of an odd tune. Looks like it's got some airplane gears.

Thank you for your reply. Yes stock DBC TB. I will try adjusting the TPS. The motor was supposed to be Dyno tuned. At the moment I have 2.41 gears in a 86 El Camino. Plan on changing gears once truck is running and back on the road.

[[email protected]]

I still cant figure out what my issue is, or what to look at, I replaced the IAC with a brand new Delco part, It wont idle when cold unless you feather the gas but once it gets to about 150 it goes tp closed loop and idles fine. can anybody please give me some ideas of what to look at ?

[blindsquirrel]

What do the trims do when it goes to closed loop?

[nitrousbob]

I have an lq9 with a summit 8706 and with the stock tb I didnt have to drill it neither on a 90mm tb. need to log those IAC counts, get your ve table good around idle (thats just a handful of cells where it sits at idle, FULLY WARMED (I even do it in open loop to get that ve table closer, or just make sure your STIT and LTIT's arent fighting you), dont be doing stuff cold until you get it to run warm), and search youtube for ChopperDoc IAC count tuning will help you get those IAC counts in line, once you get them closer (within a few numbers of error after a few sessions) then you can see your IAC counts closer to the right number, then back your throttle plate screw until you get around 60's ish or bring it up if you have to, dont forget to reset your tps by unplugging and cycling your key each time you move it. after all that things should start to stabilize but its not magic, just a little adjustment at a time towards the goal.

Lots of great threads on here about idle,