So Im trying to be a good owner and do the necessary maintenance, and I change my fuel filter last week. I went step by step in the haynes manual and everything worked out fine...until.. my idle issue. At idle, the engine is being a bit tempermental. Reving to 1000 then dropping to 300 and back and forth. Under load from the ac unit, it will just cut off altogether. I checked a few things that may cause it and had it obd'd at autozone and it says it is idleing too low. 1. Bad electical connection 2. Dirty fuel injectors 3. Fuel pump disfunctional. I sprayed the electiracal connection with electrical cleaner, I put in a bottle of seafoam, and check the connection for leaks. Still having issues. Anything else you can think of that could be the problem let me know. Stumped here.

 

Welcome to the site!

Not sure how much of an issue it is with the newer generation trucks, but my vintage had problems with the Idle Air Control (IAC) solenoid gumming up, causing erratic / surging idle speeds. Remove the valve, spritz the internals clean with carb cleaner (generally a great deal of carbon buildup seen), and good-to-go again.

Good luck, and keep us posted on what you find.

 

Did you cycle the ignition key several times before starting the truck to prime the system before driving? Sometime you will get an air trap in the fuel rail causing this to happen. I have also see what the previous post said about the IAC. Oh, just in case did you put the filter on in the correct position? If I remember they are suppose to be installed according to the flow direction marked on the filter.

 

and it is not tossing a code or triggering the MIL?

 

I just wanted to let you know that I am CURRENTLY experiencing a rough idle, only when in drive, and stopped--as in at a light. Further, my boss's work truck had a similar issue which ended up being junk on some sensor that the Ford dealer pawned off on the shop that performed the oil change leaving junk on the filter. I suspect a bigger "service bulletin issue" that Ford's hiding.
My truck has the 4.6V-8, the boss's is a 5.4V-8
Anybody else know anything on this??

 

Had the same issue with my 5.4 3V, since new and the dealer told me that they just run that way. A year ago I found a TSB that called for reflashing the computer and replacing motor mounts, dealer performed procedure under warranty and slight improvement, possibly. A few months ago I started having what felt like a tranny problem, and became an apparent misfire as it became progressively worse. Located a replaced a bad coil, the misfire was resolved and the the engine now, at 50K miles idles the way a V8 should, smoother than ever.