Drilling TB or Adjust set screw?
 

I installed a comp 216/220 Lsa 114 into my truck. Motor is Lq4 6.0, full bolt on', with stock intake mani and TB.

Met up with Justin at Black Bear Performance to correct my bad idle/stalling issue. He played with the tune for a while and we could not get it to idle right. He turned the IAC all the way up for max air at idle and it was still not wanting to idle and would still stall. He told me to clean the IAC, which I did about a month ago so I know its clean. He also told me to drill the TB blade, which I did and it still has not fixed the issue. I have went up 2 sizes from the stock hole size, using standard sized bits. Im scared to go up any larger.

The truck will crank and idle fine once warm now, used to stall and not idle, but when cold will not stay running at all. My idle is a little higher now then what I would like, but I can live with it. Im guessing thats due to drilling the TB blade, hence why I don't want to really drill it more if my idle is going to keep getting higher. He did leave the IAC or whatever you call it pretty high IIRC to help it idle once I drilled it.

So I did some searching and reading and some people are for drilling others are not. I have came up with 2 options...

1) Drill it bigger....How big is to big???

2) adjust the set screw and reset the TPS....have heard good and bad about this.

Any advise?

Thanks
-Cody

Something is wrong if you have to drill that out. That's not much cam for a 6.0 to have to drill that out. I would try a new iac first..

If you have to, open the throttle blade more with the set screw, you can already back that down and can't undo a hole drilled in it..

Might try this. If that don't work might get new tb

Justin at bbp couldn't get it to act right. Maybe bad iac. Not sure. He told me to drill it out. Which kinda helped when its warm but cold it's still stalling

you really need scanning software to do it the "right" way. adjust your blade stop until your TPS sensor is reading within correct operating spec.

let the truck idle up to temp and check your IAC counts. with a cammed vehicle it should be somewhere in the 60-80ish range. slowly drill the throttle body until your IAC is within that range at idle.

in the end, i also agree that your cam is too small to need to drill on, but scan and find out for sure.

i fought the need to drill my throttle body for years. I kept reading "a real tuner can make it work without drilling" or drilling is a a "bandaid" in the end i was taking advice from people who didnt even know how to tune.

i suffered with idle tuning, and had wheatley chasing his tail for years. tried differeint MAF, throttle body, gaskets, and 10,000 different settings in the tune and after drilling he spent about 5 minutes on the tune and it was a completely different truck. i wish i took his advice and drilled from day 1. my 247/255 cam drove like a stock truck (just didnt sound stock lol)

With a little 78mm tb i dont see an issue with drilling a tad. i like to adjust the throttle screw if possible to make it work. i drilled mine out just a hair and tuning became a breeze on it. i have zero issues with idle in my dd with a 230/236 112 in my 5.3

Drilling anything With that tiny cam is flat out wrong.

99.9% most likely. a quick check with a scanner will tell for sure.

Why is this the range to shoot for? What's the downside of being outside this range? I have adjusted my idle airflow in the tune but haven't looked at the IAC steps yet.