I picked up a '12 Ecoboost last week and Im noticing a rough idle on a cold start up. The rpms flicker around.... anyone else notice this? Im wondering if there is a reflash for the PCM to resolve this. Im also a victim of a vibration at 60-70k which Im thinking is the drive shaft (According to a user on here)

thanks

 

Dealer time....

 

The idle flux is normal, albeit super annoying and absurd for a new vehicle to do it.

The truck runs super rich on initial start up to warm up the cats faster to assist with better fuel economy. If your idle smoothes out after driving some, then all is good in that category, the dealer will do nothing for you.

I dont understand the numbers you posted there and what they are in relation to.

 

My bad... 60-70 Km/Hr

 

You're half right/half wrong. A rich fuel mixture cools the charge and does not warm it up whatsoever. A LEAN fuel mixture and/or retarded ignition timing is what causes combustion temps/EGT's to increase.

What he's experiencing at start-up is retarded ignition timing which ignites the air/fuel later in the power stroke, thus increasing the EGT's which then in return warms the cats up quicker. So yes, the cats are being warmed up faster, but not from a rich fuel mixture but rather from retarded ignition timing.

You can read about my thread outlining this issue here

 

your ecm may need reflashed. My Superduty did that (400-800 rpm hunting at start-up). They did a reflash and everything was fine after. My EB is glued right at 500-600 rpm's at cold start and never moves.

 

Here is a perty cool thread, dated but informative I believe.

http://api.viglink.com/api/click?for...13483327238261

Some are finding the spark plugs gaps all over the place, with too wide gaps and installed overtightened OEM.

 

No, that's not the issue. I posted what the issue is right here:

https://www.f150online.com/forums/20...-start-up.html