I have posted on this 94 Villager before, I always had stalling problems since I bought the car 2 years ago.
I put an used transmission in a few months ago & started getting Trans codes such as open circuit in solenoid packs or in sometimes only in reverse module(cant remember this one). At one point I did the Haynes voltage check on the Tps sensor & couldnt get a good reading, I replaced Tps & and got the same reading, 3ma instead of 5 volts. I tried to manualy adjust the Tps & take readings as per Manual, no luck, but the car stopped stalling and only stalls if I move the Tps too much up or down, I suspect if I had done this with the old Tps, it would have stopped stalling.
I checked the voltage at a couple places further down the wiring harness and still same readings. I got ahold of an used computer(ECU/ECM), put it in, and same Tps readings, which leads me to suspect that the Computers are not the problem.
Now to the point: Trans has a few months left on the warranty, if its bad the Junkyard will take some responsibility, but I dont know if the incorrect Tps readings are caused by an electrical problem somewhere in the wiring system or because there is something in the Trans giving bad signals to the TPS. Transmission shops tell me that the Tps sensor affects shifting and have had problems with Tps/Trans before.
I dont know whether to take it to the Trans Shop who charges $100 to test the Trans(also with their computer) or to an Diagnostic specialist who analyses different systems on the car, but charges like $150 for per test for example Electrcal Systems, Trans, Computer, etc.
Anybody with some knowledge about this?

Hi, RE, your request for info, Do yourself a favor and check ALL the electrical connections to the trans, Clean up the connectors with an electrical cleaner and lube them with dialectric coumpound, Did you mention coil packs, Common problems are connectors at these points, When ckecking the connectors look for GREEN and or corroded terminals, LAST but not least CHECK the GROUND connections and ground strap from engine to body, GOOD LUCK....., Clay....