After reading the 700/900 forums, I pulled my throttle body and IAC. As expected there was significant crud built up inside the TB. I thoroughly cleaned the TB and reset the throttle position switch, did a light cleaning of the IAC (wasn’t nearly as bad as the TB) and re-installed.

After a stupid trick with the blade fuse for the FI system (pulled it -- yup, it crummy looking -- put it back in -- damn thing won’t start -- cursed car -- pulled fuse again -- replaced fuse w/ new one – car started fine – cursed myself) I re-attached the throttle linkage and reset it and rechecked the TPS to be sure it clicked when I cracked the throttle.

I wasn’t surprised to find the idle high, but I was surprised to not be able to adjust it down (to 700rpms with the IAC test wire grounded) with the idle air bypass screw. Best I can get is around 900rpms, then the idle air bypass screw is turned all the way in. The throttle itself is completely closed and I’m pretty sure I set the idle stop set screw correctly with the 1mm gap. Now for the questions:….

Idle speed will go up when the IAC test wire is removed. Can I assume the IAC is okay?
I looked for other leaks of unmetered air getting in without the AMM ‘knowing about it’ using a liquid around all the injectors, ducts, vacuum hoses, etc. with negative results. Is there any other way?
Should I be looking at messing with the AMM and CO mixture? According to Bentley’s manual, it looks like I need to do a kind of balancing act with the mixture and the idle to get things worked down to where they should be. This seems pretty bold for me, and before I do it, I’d like a second opinion from some of you “pros”.

Thanks in advance, and I’ll update if I figure anything out.
Doug
1988 240DL B230F, automatic, 247,000miles