I have a friend who's up in years and out of state and is having issues with a 1987 240 sedan that he recently had a major overhaul done to. I'm asking this for some second opinions to arm him with some idea so he doesn't walk into an ambush at a local shop.

Here's the Reader's Digest condensed version: he has a 1987 sedan he bought new. Put 260k on it when it developed a bad knock. He bought a new crate motor (production date was 6-95) and a newer rebuilt AW71L. Every vac line, IAC motor, sensor, etc was replaced. He also had the ECUs replaced with reman new (car was converted to Bosch 2.2 about 3 years ago). I suggested the fuel pumps + relay and he had them both done - OE Bosch (the updated turbo in tank as well). Car runs like a gem....except when its cold (engine temp - not ambient). He says it hesitates like a miss but the tach doesn't flicker. He said it feels like someone is turning the AC on/off - like an on-off load. Withing 5-10 min, it runs fine and doesn't do it again unless it sits for several hours and he goes out again.

Could it be the tranny? I have a later 71 locker in mine and it took some getting used to - downshifts fast and harder compared to the old 70. If I were there I could drive it myself and then hypothesize for all eternity. Just wondering if anyone here recognizes it as something obvious to check.