Loping (rolling) Idle

[G8wood]

After all the work I've done recently, all of a sudden the idle will lope along- intermittently- took out the EGR, tested it on the ohm meter and cleaned the heck out of it, started reved the motor, then replaced the gasket, and unit, used brake cleaner on the plug-
When its cold is the biggest loping, once it warms up, its gone, or barely noticeable.
I retared the timing a bit and that reduced, but not eliminated the problem.
Where to start?

TIA

p.s. 109K miles on it

[Blue Bowtie]

In all the work you've done recently, did you happen to clean the throttle body and IAC air passages?

[G8wood]

Originally Posted by Blue Bowtie

and IAC air passages?

Positive on the throttle body...but the IAC? oh boy, off to google to find out what/where those/it are/is.

[Blue Bowtie]

The idle air control stepper motor is mounted in the throttle body. The pintle and seat can become contaminated with varnish, and the rack gears on the stepper motor coils and on the pintle shaft can be contaminated, causing either sluggish operation or no movement at all.

[G8wood]

Cool pic- thanks, better than the crappy pencil drawing in the manual!

CWG