Ok,
My truck has been idleing a little high for a week now. I thought it was soemthing to do with the o2's. I was in traffic and decided to switch on the a/c. I switched it on and then off after a few seconds. The truck then started to idle normally now. Any ideas as to what may have cause this and what fixed it?

Pasta

 

When the A/C is switched on, your RPM's should go up a bit. This more than likely only masked the rough idle. Mine idles pretty rough too, but with a few hundred more RPM's, it feels smooth.

 

How long has it been since it has had a tune up? Might not be a bad time for the usual air filer, fuel filter, plugs and a lil fuel injector cleaner. The computer might be bumping up the idle in an attempt to keep the engine running. I am new to ford but I know other trucks have an idle adjuster that will increase idle automatically based on load. If the engine is running rough the computer might think it is under load and running hugher rpms to help compensate and keep the motor running. After a tune up it might not have that problem. Also clean the mass air flow sensor (or whatever ford calls them) and it wouldnt hurt to run a can of seafoam through the gas

 

Do the mod motors have a idle air controller like on the windsors?

Adrianspeeder