This all started when the weather got cold. When the truck start up it idles really rough and the whole truck rocks like it has a cam. To me a sound like it has too much fuel and sounds like missing on the exhaust. When it idles why is the spark all over the place? Here is the log file.

 

Can you post your tune?

 

Sounds like it's a case of denser air, and fuel feed is surging trying to adjust. Slight AF change in tune should take care of that.

 

take a look and let me know.

 

Well i was looking at my old log files and my log new file and found that lfts are realy high 02 are runing lean. So think i have leak some where.

 

I sometimes have this problem, in a way. I just give it a few revvs if it does it and that usually fixes it. If it doesn't, I just make sure I get the motor warm quick.

 

Intake gaskets are a big problem on these trucks, they leak vacuum at the bottom edge and the problem shows up as soon as it gets colder out. I would check those out especially if you ltft are running lean.

 

Maybe the cold temps are opening up a bit of an exhaust leak. Might be worth checking.

 

Well I got the problem fix. I cleaned the maf, intake tube,filter, throttle body, put a new fuel pressure regulator, and found a lose vacuum hose. The lfts look a lot better than the last log.

 

Just a tuning FYI- It doesnt have to be very lean to affect idle however it can be pretty damn rich without a noticable change in idle. For referance I have seen mine idle just fine at 11.0 afr however on the lean side I start noticing a change in idle at about 15.9 or so AFR.