Ok so I currently just installed a 94 JDM Automatic DOHC FWD Transmission into a 93 SOHC Stealth Base! The transmission bolted up and fit as it should and all the electrical plugs fit perfectly. I had a mechanic help me install it. The old transmission was slipping really bad, getting stuck in gear, downshifting hard, and grinding gears etc. Well anyways, after installing this JDM transmission I am experiencing new problems. The slipping is completely gone so burned clutch packs are no longer a possibility. I even checked the fluid and it was at the appropriate level and did not smell varnished or burnt. The problem is the car downshifts really hard and when the car is at a complete stop idling in gear it just wants to stall after coming to a slow down or stop. The RPMs drop to about 500rpms and sometimes i even have to throw it in neutral to keep the engine running. Then when dropping it back in gear the rpms go straight back down to around 500 and the engine runs really rough. I am certain it is not an ISC or TPS issue because i have replaced both sensors already and the problem was not apparent until after the transmission swap. The issue I am experiencing is most likely electrical. I am assuming its the valve body or solenoids. As you may already know, the TCC (Torque Converter Control) solenoid controls the torque converter inside the trans and as far as I know it controls when the converter locks up. I have a feeling the solenoid is malfunctioning because the RPM dropping/stalling issue could be the torque converter locking up when its not supposed causing the engine to run rough. It sometimes feels like the converter is locking and unlocking while im driving at cruising speeds and the shifting isnt the greatest. Does this sound like an electrical or mechanical issue? I neglected to mention the trans vin reads F4A331UNQB which mean the transmission actually came out of a 94 with a 3.5L 6g74 DOHC engine. Keep in mind it bolted up to my 3.0L 6g72 SOHC motor perfectly. The transmissions are the same internally.

 

I do not know exact specifics as I have a trans builder who does all that for me but I do know there are several versions of the trans that look and bolt up the same but have different solenoids. The solenoids have to be matched up with the correct auto trans computer or they will burn up. I have seen it several times. I only swap the trans between years when I also have the corresponding trans computer available to swap with it.