86 300E power loss at speed

[A264172]

Happened twice today. Car fully warmed up temp (90C+). Both incidents were on highway at aprox.60 mph. Economy gage pegged in red. Oil pressure good (pegged). RPM's responded to pedal but produced no power. As I would pull over and pump the gas to get a little further up the berm I would get slight little bits of power transmission. Let it sit for a couple minutes and it started right up and did not loose power till the next 25mile highway trip. Both times uphill.

Looked for vacuum leaks between the two stalls but the symptoms were not present during testing. Replaced the cracked crankcase to intake manifold hose.

Thinking vacuum leak...

Or crankposition sensor (do rpms stay under control of accelerator pedal during cps related stalling?)

Other possibilitys... coil?... valve cover gasket?... ???

Any suggestions, ideas, or experiences appriciated.