I had the truck warming up outside the house and I was in the house and notice the engine slowing down to almost the dieing point then fire right back up to I'd guess 1600 rpm and back to run normal

would there be a misfire or fuel or something?? truck still runs great

 

could be the A/c compressor kicking in and out. They purposely do this so the refrigernat cycles during the winter cause we r never gunna put the A/C on during Novemeber.

 

Mine acts the same way when it gets cold.
Mine had codes, and it showed that all 4 o2 sensors showed a fault as well as bank 1 and 2 misfires, obviously all 4 sensors arent bad at the same time, a friend of mine that worked at ford says he believes it may be the MAF sensor.

This may not be the same issue as yours, because any time i idle longer than 15 seconds it starts to misfire, but anytime its running down the road it runs perfect.

 

The reason the A/C kicks in on defrost is it helps aid in defogging the windshield, a/c is better at pulling humidity/moisture out of the air, and aids in keeping the windshield clear.

 

That as well.

 

oh ok ya I had no codes. this is the first time I notice it


thanks

 

My truck did the same until I replaced my intake gaskets as they where sucking in unmetered air. This problem came back 6 months later due to a blown head gasket on #4 cylinder.

 

my truck I believe is starting to do this runs ok down the road but it idles like crap warm or cold

 

Also I believe the MAF sensor is mass air flow sensor?? which is located sort of in the air filter housing I sprayed it with electrical cleaner spray would it be a bad idea to do it in cold weather and warm spray?

 

I hope the spray you used was for MAF only do not use any other spray. Do not spray directly into it