Recently my trucks been idling rough on a cold start. Does this for about 3min. I had done an idle chop tune and was happy with it. One night, my truck sat outside and got really cold. Started it up and it was way lean, even died twice. So i put the idle parameters back to stock. Its been better, but still does it to some degree. Sounds like it has an aftermarket cam. However, when it does it now, my wideband indicates rich. Also, when i come to a rolling start and tip into the throttle, its kinda hesitates before taking off. My truck has a maggie on it, just put on in november. No codes. Maf table has been tuned with stft's. Recently did an ls7 throttle body and pcv catch can, gaskets/vac lines looked fine then... Im running tr6 plugs and 93 octane gas. Any ideas? I really hope it isnt intake gaskets. Ive never had much success with the carb spray method of checking gaskets, but im gonna try that tomorrow. Ill post a log of it if it acts up, as well as my tune. Maybe its something im missing in the tune?

 

May try some new plugs tomorrow too, as theyve seen all kinds of wild afr's while I was getting the tune lined out.

 

Idle chop tune?

 

Making the idle over/underspeed tables (spark/airflow) have a greater swing.

 

So in other words, screwing up the tune to make it sound like it has a cam? It has to be really rich to mess up idle quality, however a little lean and idle will change. Did you ever change the tune for the larger TB?

 

Think I found it. I missed a couple airflow tables. Guess Ill see when i start it tonight after work!

 

Started fine from a 67 degree ect start. But its been in my garage all night. Ill see what it does after it sits outside at work tonight and try to get a log.

 

Kinda just desensitizing the idle quality parameters. Saw a video on it and decided to give it a try. Hopefully no harm done. And yes, i pulled the etc scalar from a z06 tune for the ls7 throttle body.