I've searched and found very little one this issue. Is anyone else having this problem?

http://www.youtube.com/watch?v=nU8el...ature=youtu.be

Whenever I first start my 2012 F-150 with the 5.0, it idles rough and if I step on the gas it acts like either an injector is cutting in and out or it's missing. It doesn't really seem like a miss though, more like an injector/fuel issue. I have no idea what it could be. If I let it sit and idle it won't go away unless I step on the gas and get it > 2500rpm or so. Thoughts?

**The problem/fix**

Well I figured it out for real this time, thanks to Mike at 5startuning. He mentioned how Ford has different cold start tables, and the first one the ECU looks at on cold start is one where ignition timing is retarded....yes, retarded! So I hooked my phone up to the OBD2 port and sure enough, when I first start it, the ECU retards ignition timing 9 degrees! No WONDER it'll barely run!! What a stupid move by Ford. Check it out for yourself....



I've already ordered 3 tunes from Mike where he has changed the cold start timing from a negative value to 20*. I'm certain this will fix the issue.

Basically, the reason it idles rough at start is because of the retarded timing that is supposed to decrease the time it takes for the cats to warm up.

 

Am I really the only one having this issue...?

 

Only time I've seen it.

 

shouldnt you take it back to the dealer?

 

My 12' 5.0 is slick as glass at start and at running temp??

 

My 2011 has a slight rough idle at start. I normally smoothes out after a minute or two. If you stop at a traffic light you can watch the tach jump a little bit but you can't feel it at normal operating temp.

Does your's surge a little under load when you start going up a hill while it's trying to hold 6th gear. I assume it's something to do with the VVT and I guess it's normal?

 

No, once it's running smooth, it runs great. It's only at start-up. I have to rev it up a little to get it to smooth out. It doesn't surge at all under load, just when I start it up it does this.

 

I am having the exact same problem. My truck is about 2 months old and has 1700 miles and today its was really acting up. If I'm in a hurry and throw it in gear, it just stutters really bad and won't hardly move for a few seconds. It feels exactly like its missing but then after a few seconds, it levels out and runs great. Its such a weird problem.

 

Sounds like it needs to go back to the dealer. My 2012 starts just fine

 

x2!!!

 

It's not that it doesn't start, it starts, it just runs rough AFTER it starts. Next time yours starts, let the oil pressure build up, then step on the gas and bring it up to around 2000 rpm and let me know if it bogs down and makes a weird noise...it's almost like it's hitting a rev limiter/fuel cut...it's so odd.

 

That's why I agreed with benzo911....

It's a new truck and shouldn't be acting like that...

It's under warranty...take it to the dealer and let them diagnose the issue...in my experience it doesn't sound right...

there's a handful of things that can be causing this and its best to let the dealer figure it out...IMO

 

I've had an FX4 5.0 for about 16 months now. Baby purrs like a kitten. No rough idle here.

 

I agree. I took it to the dealer today. They'll check it out in the morning when it's cold (since that's the only time it does it) and then let me know what they find.

 

My FX4 has on a few occasions felt like the engine was missing when I first put it into gear. After about 30 seconds it smooths out. Only 1400 miles on it. It is going back to shop next week so it can be checked out