Generation IV External Engine - How to adjust engine timing LS2

I cannot get my LS2 idle speed down below 1500 rpm. It has an Edelbrock manifold and speed demon carb. I have not tried to map the ignition timing using a lap top, but before I do, wondered if there was any other way to adjust the initial timing (like turning the distributor on a conventional V8). The engine feels like it could do with a bit more initial advance, but if I set it up with the software, does it remain programmed into the MSD module?

Are you using a PCM to control the engine, or a dizzy? If using a dizzy, then you'd do it the old school way. If using a PCM or an MSD Module that you HAVE TO program, you'll have to fire up the laptop to make any adjustments.

I cannot get my LS2 idle speed down below 1500 rpm. It has an Edelbrock manifold and speed demon carb. I have not tried to map the ignition timing using a lap top, but before I do, wondered if there was any other way to adjust the initial timing (like turning the distributor on a conventional V8). The engine feels like it could do with a bit more initial advance, but if I set it up with the software, does it remain programmed into the MSD module?

You really need to post in the carb section where you'll get more responses. Nice car BTW!

IIRC, this has been a recurring problem for you and I'm tempted to say you have an air leak somewhere causing the high idle speed.

The MSD box does retain all programming (key on or off) until someone puts in a "pill". That will override your settings until removed, then it reverts to previous programming.

It does behave like an air leak, a bit erratic. I have been over it several times with a vacuum tube stuck in my ear, but I cannot find anything. Which lead me to believe that it must just be too loose on initial timing. I will borrow my daughters lap top today and have a go at mapping out a curve.

Stupid me, I didn't realise there was a carburetted forum here. Brilliant!