LT1 POWR

So I took some readings last night. Outside temps were around 30º and motor was cold. I fired it up and it died a couple times. When it started to idle the IAC counts were maxed out at 310 and stayed there for a couple minutes. At a warm idle at about 190º the IAC counts were at 110 in park and about 115 in gear at about 750rpm. What do I need to do to get it to idle while cold. When its warm it runs perfect, its just the first couple minutes.

Also while its cold and I put it in gear it dies unless the IAC counts are at about 150 or lower.

97WS6SCharged

Are you still using the LT1 manifold or the single plane? Either way it sounds like you might need to crack the blades a little bit at idle and adjust the TPS.

LT1 POWR

Holley single plane with a AS&M monoblade. TPS is around .54 at 0% throttle and 4.62 at 100%. I cracked the blades open just a little and it was idling at around 1000rpm. Is there anyway to lower IAC counts without raising the rpm too much?

roguedriver

What are you using for tuning? Sounds like it needs a lot more fuel on cold start up.

Ken R.

LT1 POWR

EFI Live. Might switch to HP tuners though. I don't have a AF ratio gauge hooked up, but it smells pig rich on start up.

DirtyDaveW

What is your timing advance set to for the Idle spectrum RPMs? Mine is set to 30 and the resulting idle is much stronger. Are you pretty sure you don't have any vacuum leaks around the throttle body where unmetered air can get in? I'm fairly sure you know all this and don't mean to insult your intelligence Just covering bases.

roguedriver

Really need that A/F. Its possible its too rich at start up, but you won't know without a wideband. If you can tune, start messing around with the start up and cold tuning. Never used EFI Live or HP so don't know the exact terminology they use. I just know what Tunercat and FAST use cause thats what i'm familiar with. I had a hard time on cold start up as well. Would stall at idle and cut out stepping on the gas. I actually had it too lean at idle when cold and adding too much fuel when i could open up the throttle body. There are a couple of tables to adjust those items in the FAST set up. Once i got it right, it ran great. There is a lot that plays into your problem. Timing, fueling, IAC adjustments. A wideband would be very helpful though.

LT1 POWR

We hooked up a fogger machine and fixed the major leaks, but every motor is going to leak a little air. I'll have to look at it, but I think idle timing is around low twenty's/high teens. That's what I'm seeing on my scanmaster anyways. Before I knew we had some pretty major air leaks, we had to lower the timing to get the idle down, so there is a good chance its set too low now that we fixed the air leaks.

I'm going to drop it off at the tuner and let him have it for a while so he can dial in the idle and stuff. We really only messed with getting it started and WOT tuning. I just want to be able to let him know some places to look, although I'm sure he already knows. He's very familiar with both LT1's and EFI Live.