Have a 2001 F150 FX4x4 and since the weather changed and started having days below 40 the truck has started running rough for about the first 15-20 miles. When you first start it starts like normal for first 3-5 min and then it starts loping real bad like it has a cam in it! Any ideals? Thanks in advance.

 

First thing is to check for stored code.
If nothing stored you need to look at live data with a Scanner to see what is out of normal.
It could be as simple as a thermostat not letting the motor run at normal operating temperature.
You would see this on the Scanner data.
The reason the idle gets rough is the air/fuel ratio is upset.
Your looking for the reason why.
Good luck.,

 

Thank you sir for the information and for the quick reply as I had no idea where to start because the old truck had been great until weather turned cold. thanks again!

 

I am having the same prob with my 01 5.4 have you been able to fix and if so what did you have to do

 

I'll refer you back to Bluegrass 7 comments. or post #2

Not trying to be rude or grumpy...but
Everyone's situation can be different the OP (original poster) might have gotten by with a T-stat, IDK ,your situation might call for new plugs or a vacuum leak. the point is it is best to start with the scan and then work your way down.

If your situation is not turning out to be typical, then start your own post with what you found and go from there. Jumping in on somebodies else s can offer confusion and maybe delay, or unnecessary money spent.... Again...Not trying to be rude or grumpy there is host of good info here. "search" can be a very good friend.

 

*Might not be (or shall I say probably not) same issue but...*

When cold weather came my 01 cut off after a 10 minute drive...But engine light came on and it was the idle air control (about an $80 part). Took less than 10 minutes to change.

Another time it was idling funny it ended up being a vaccum leak way up underneath the wiper blades in the middle back area which was non visible...

The vacuum leak didn't throw any codes so maybe beginning stages of a leak somewhere?