A couple things...
1) It is fairly normal for Renix 4.0s (1987-1990) to crank for a bit before kicking over. The ECM is programmed to not send signals until the CPS reads at least 300rpm - that's directly from the Renix FI manual. It's supposed to help with internal oiling (and seems to!) - but there's nothing to be done, so you might as well get used to it.
2) Could you be a bit more specific about "idling over 210*" I'm not sure I understand what you're talking about there, so I'll not address it until I hear more. Normal operating temperature for the 4.0 is supposed to be up around 210* - which doesn't mean that we have to like it, and a little work can reduce that to about 190* without impacting tailpipe emissions, durability, or fuel mileage.
3) Did you move ALL the donor electronics when you did the tranny swap? I'd have to see what else (if anything,) but I know that the TPS is different between the manual and automatic transmission up to 1990, as well as the ECM (and, of course, there is also the need for a TCU for the AT - not required for the MT.) I ask in the interest of being thorough - I'd like to assume you got everything, but the only dumb question is the one not asked. On the flipside of that - what did you do with the clutch pedal/master hydraulic setup? Just interested - it would save me looking for one on my own conversion later....
5-90
