iv been resurching on this alot and playing with and checking the systems on my car. my car is a 89 NA. was auto converted to 5 speed.
*throttle cable is loose
*checked BAC resistance good clickes when 12V applied. engine bogs with acesorys when unpluged
*AWS valve resistance good clicks with 12V.
*thermowax hard to see but looks to be extending properly
*throttle plates seem to be shuting barly some times like spring is not returning right. (is there a way to adjust the spring strength?)
*checked the bank of 5 valves/switch things for proper function
*nerrow band TPS is functioning corectly
*wide band TPS is not functioning corectly. resistance starts in spec, then in middle spikes at around 30 k ohms. then drops back down to 6 k ohms.

my car was idleing at 2k before i started messing around with it. now i got it down to around 1- 1.5k but it runs realy rough. (posibly vac leak). also wanders a little. could it be my AFM maby(is it worth checking?). also how do u adjust the mixture. i think part of the problem is that cus it dosent sound or smell right.
i have not checked compresson cuz i dont have the tool. thanks in advance for your help. o ya and it dose a little reving but i think thats do to the bad wide band TPS. it i remember right it didnot do it when unpluged. also didnot do it when it was runing at 2k.

i also think the mixture needs adjustment cus when i rev it up and hold it at 3k it will puff a little. so not rough only at idle.

 

All old rotaries idle rich, so the smell is normal.
It is not adjustable except with a piggyback like an Apexi S-AFC.

You're right about a possible vac leak.

Rough idle below 2K - do a compression test.
A normal compression testor can be used in the trailing hole. With the vent valve closed you get the peak pressure. Then open the valve to see if all three bounces from the rotor faces are equal.

That spike in the wide range TPS will make the OMP go full on intermittantly.

 

ok. so thats why S4's dont have the wideband sensore. cus there mecanical linkage to omp. so the fact that the widband is bad wont have any effect on my idle, directly. only will cause it to dump to much oil into the combustion chamber in the mid range. maby thats my puff problem at above idle. so all see about geting a compression tester and a bottle of propain to check for vac leakes. thanks.

 

i got my idle down to about 800 rpm! yay. the motor was rebuilt, and they adjusted the stop screw for the lower buterfly with the thermowax cam engaged. so i just reset that stop screw to the proper place. also cleaned around the buterflys to make shure there closing all the way. but to get my rpms that low i had to adjust the BAC screw almost all the way down. only about 1 turn from botom. is that normal?

 

As long as the the idle air screw in the BAC is not full closed or full open, you're fine.

You mentioned the throttle wasn't closing right. Maybe lube the throttle shafts.
I use spray white lithium grease.

Home Depot has CRC 2-26 spray contact cleaner/lube in the electrical dept.
Working it into the TPS plunger might save it.