OK today I thought I found it. Studs holding down the fuel rail/plenum spacer were loose, 3 out of 6. Changed all gaskets, replaced fuel injector o-rings, cleaned fuel injectors (very dirty). Torqued every thing down good. New AIC motor, new crank sensor, new PCV valve and hose, still surges (bogs). Have a new coil pack in the box, reluctant to throw it in yet as when I pull the boots off the old one while running there is a good strong arc over an inch long, looks consistent on all caps. I have it anyway, worth a shot.

I have 2 thoughts now. First, this is not the original or same motor. I wonder if there is a chance of mix match sensors not matching, I don't know if the computer was changed or how different the management systems are. Second, this guy told me months ago he needed both 02 sensors, per autozone or whoever pulled the check engine codes. I only came up with the lean codes, P0171 and P0174, along with the EGR and #5 misfire. Could it be as simple as 02 sensors without any codes for them, and no lean codes anymore (yet)?

So now I'm lost! Could try the cam sensor, its cheap enough, they just didn't have it in stock. Thanks for the help anyways guys.

 

If the 02 sensors haven't been replaced, may as well do it. They can cause a lean/surge when dirty or going bad, and if it doesn't solve your problem they are good to replace as a preventative anyway.

 

Another thing to check is the fuel filter. Some varieties have and internal chack valve that may malfuntion, other than crud build-up. Check the fuel pressure too. Pump may still be functioning, but if on it's way out, may not be building enough pressure at idle to open the injectors properly.

 

Well I think I "fixed" it. Replaced both upstream 02 sensors, helped out a bit with the bogging, not very much, although the exhaust did smell cleaner. So I started cranking up the throttle stop (idle) until it smoothened out. Now it sits just under the 1k line, maybe 950 when in gear. No change at all when the a/c engages now, except when in park/neutral it does jump up to around 1400 for a second. I ended up turning that screw in about 1/4". A bit higher than I'd like it, I think there still is an issue somewhere, but without throwing anymore money into it I think it's good.

Thanks very much to all that posted, stinks not having a real time scan tool. I think that may be my next purchase, makes diagnosing much more definite. Or I could stick to my day job.