Need ya'll to bounce a few ideas off my head. A month ago my alternator failed. It was replaced. All is well.
Ever since then, I've been getting an occasional high idle. Usually is 600-650. Now sometimes it bounces around 800-850. Throttle body still looks good. I'm going to pull it today to be sure. MAF is clean. No codes. And in the last two months I've had two separate rough idle events that were cleared up when I hammered the throttle. I re-checked torque in all plugs yesterday and cleaned everything up. Fuel filter is new. The way I'm seeing it... my options are these, or a combination of these:
1)Throttle body going bad
2)Throttle position sensor
3)MAF going bad
4)Baby vac leak somewhere.

thoughts?

 

Also, while driving, I can sometimes hear/feel the throttle "feathering" for lack of a better term.

 

This is as much gut reaction as anything, but my nickel is on the TPS.

 

Thanks Perry. That's kind of where I'm leaning. I'm gonna go through the whole cleaning song and dance again, see where I end up.

 

Circuit board on side of throttle body motor decodes signal from pcm then drives motor to adjust throttle plate . This feathering of throttle plate is either a bad motor circuit or pcm receiving bad/poor signal from crank sensor . I was thinking that pcm gets its rpm from that and developes a vss signal ?? I lost my 05 throttle body due to a bad series ford made in 05 . I changed TPS first and cleaned TB but it still would shutdown every few weeks intermittently sometimes at the worst traffic condition . Its model number started with a 3 and was replaced by an up graded 8 . Anyway that's why I had to look into how it worked , if there was a difference of the tps point and where its supposed to be at mine would shutdown just bam and cut off . I put a oem TB on and that was years ago . Maybe yours is not off far enough to shutdown . Of course I would clean TB motor connector .
Someone else may have a better take on this operation .