I have just replaced the engine in my TS, the previous unit threw a rod whilst cruising on the motorway at significantly above the legal limit, it had done over 140K miles so is forgiven!
I installed the replacement lump which came with coil packs and inlet manifold. The unit fired up on the first attempt after turning over just enough to feed some fuel through. I ran the car up to temperature, filled up the coolant, checked the oil etc and all was good.
On the first run out of the workshop I accelerated, changed into second and the engine just died, repeated attempts would sometimes result in the engine starting, idling poorly at low revs, not responding to the throttle, and then dying. I disconnected the battery for 15 minutes in an attempt to re-set the ecu - and hey presto it worked! I drove about 120 miles over the weekend with no problems and then set off for Durham, a journey of 250miles.
The car ran faultlessly, cruising at 70 - 80mph, after about 180 miles I stopped at some services and shortly after re-joining the motorway I experienced a sudden and dramatic loss of power. As I was traveling at speed I just kept my foot down and the power kicked back in. The car continued to have similar moments for the next 70 miles, luckily I got to my hotel without it dying, and it drove to site fine this morning, only about an 8 mile jaunt!