'94 850 stalling/not starting

Hi, Here a strange one I hope someone can guide me on: 94 850 turbo that intermitently wont start when the engine is hot(after its been running, then restarted after only a few min). It also "died" briedlfy while going down the rd the other day too. But after you wait 10 - 20 min for it to cool down a bit it stats and runs fine,,. I recently replaced the plugs, as well as the distributor/rotar to try fix it, no luck. The only fault codes it seems to have is in 2A as: 435 and 436, slow response from front oxy sensor, and max compfrom rear senor. When it dies, the you still have electric and all the dash idot lights. The engine cranks, just no spark,,. It reminds me of the old coroded ECU fuse deal in my old 245. Any hints ideas? Many thanks Steve