930 stalling and losing a cylinder

[quartetchiang]

Dear Pelicans:

Today after a few hot laps my '89 Euro 930 Turbo started to lose power, and within a minute, stalled. It will fire back, but unless I hold the throttle manually above 1000 rpm it will just die on me. Furthermore, the motor is making odd noises (like muffled knocking), and it feels like as least one cylinder is not working. Left it sit for 5 hours and tried to restart, same symptoms. I just sent the WUR for a rebuild, and after I got it back all was good, except when the motor reaches working temperature the idle will stay high at 1200-1500 rpm, wouldn't drop. And now this. Motor was freshly rebuilt with new pistons and rings.

Any thoughts? Getting kinda anxious here.

[aluminum]

Your in the 928 Porsche Forum so most likely would get better response in the correct forum