1996 850 T5 172,000 miles Hot soak no start

[redbeak1]

Hello, I'm going nuts trying to solve this crazy issue. When cold... starts and runs perfectly. After a 10 mile drive, I stop for 20 minutes, the car turns over but there is no spark at the coil grounded to the engine block. I keep getting code P0120. I swapped the TPS, checked wiring and the problem doesn't go away. After about and hour it starts and runs great!!!! Usually by the time the tow truck arrives. I did the following:
1, swapped fuel injection and fuel pump relay while engine was heat soaking with brand new relays. Pulled and cleaned fuses.
2. Repaired the Fuel injection connector with volvo wire repair kit from FCP #3523813. Fits perfectly.
3, Replaced Cam position sensor.
4, Swapped ECU and TCM with working units. No help
5, cleaned ground wires to the firewall.
6, New cap and rotor
7, swapped coil with a working one. No help.
8, Cleaned air filter and installed a new Bosch MAS
9, Crank Postion sensor changed 5 years ago (30,000miles) checked resistance when cold seems like it's in range.
10, New thermostat and ECT replaced 3.5 years ago. 20,000 miles

Any advice would be so appreciated. I love this car as the most perfect daily driver i could ever wish for.