autozen,
Compression test was done not long ago & they checked out fine (only 90k mi). Dist. timing is set to factory spec for diagnostic purposes (as specified earlier) but will be set again later, more for performance than emissions. Cam timing is dead on & has been re-checked half a dozen times (fresh chain, etc). All valves are adjusted properly. This isn't my first time.
aajf@ipa.net,
Thanks for the lead on the the vacuum lines. I always like to replace as close to factory as I can get. As far as slowing down the idle; try Tom's suggestion of adjusting the idle speed screw & the idle mixture screw together. (Though I don't know your specific symptoms).
Tom/Peter,
Thanks for the tips. First thing today I'll be checking the continuity in the distributor connector, chasing/cleaning grounds, cleaning points, & making sure they open. I hope like hell it's not the harness. And I'd rather not buy an ECU, but it's a hell of a lot easyier to swap out than the harness.
Yes, double & triple checked the firing order. I stopped obsessing about it after I decided that the problem was intermittent. At the moment (knock on wood) she's running on all 8 & hopefully all the checking & cleaning today will just make sure she stays that way.
Tom,
I still don't have quite as much vac as I'd like. I tried turning the idle speed screw in and I only got a very small increase (1/2in), so I must have a vac leak somewhere. I'm going to pull the lines to the power locks for now, as the PO removed some of the hardware for them anyway (& who needs power locks in a convertible?). Then maybe I replace all the vacuum lines anyway...
Updates later.
Thanks All!