What should I be aiming for the cold start afr? Right now my truck idles at like 10-11 until it goes into closed loop and it stinks pretty bad. It has a pretty crappy maf tune. I bought hptuners so I'm gonna start playing with it and convert it to sd. Just wondering what you guys are commanding on cold starts?

specs are 5.3L mp76 with a 225/225 .581 113lsa cam if it matters.

 

Sounds like your fueling is wrong unless someone messed with the startup modifier tables. Get your MAF calibrated and get the SD side taken care of and you should be better.

If you want to see if I"m right or not, log your commanded air fuel hi res during startup. I doubt you'll see the truck really commanding that rich.

 

I think mine is in the 12's, never paid much attention as it rises up to 14.7 fairly quick. My tune is OLSD without O2 sensors.

 

Yes I am sure my tune is off, my truck runs pretty crappy which is why I want to start tuning it myself but I was wondering what I should aim for at start up?

 

my cold start afr is about 13.5ish

 

I use EFILive but what are your commanded numbers based off of engine coolant temperature? It really shouldn't be that rich unless the engine is ridiculously cold, like -30 or so. Anything -10 and up is above 13:1..... Granted I am mostly stock LQ4 but it seems you have quite an "awesome" tune. And yeah....... I'm from Edmonton too........ hence why I own my own software, lol.

 

Yeah it looks to be commanding 14.7 at 0 degrees and higher. Just the -40 is commanding 9.5 and then leans out up to 0 degrees. Kinda sucks tuning around here is very expensive and to spend so much money and still run shitty

 

Do you have the current tune licensed so you can edit it?

 

Stoich at 0 degrees is way too lean. You need to be mid to high 11's if the motor is that cold. You will know when it's too lean because if you drive up the street, it will pop out of the exhaust real bad.

Anything 140* and up in the open loop EQ table should be set to 1. That is the main fueling table referenced on warm up.

I don't think there is a better purchase than your own tuning software.

 

download a stock tune from the repository and check it out