HELLO ALL I HAVE AN 87 911 TURBO NOT TO FAMILIAR WITH THESE CARS BUT THIS ONE OVERBOOSTS, I REMOVED WASTEGATE AND DISSASSEMBLED AND FOUND DIAPHRAM WAS RIPPED SO I REPLACED IT, CHECK THE EXHAUST PIPE TO MAKE SURE IT WASN'T CLOGGED, AND THAN REINSTALLED CAR STILL OVERBOOSTS, WONDERING IF SOME CHANGED THE SPRING IS THERE A WAY TO TELL?

 

You might get better input on the forum.

 

Head over to Pelilcan Tech section.

 

Didn't the wastegate springs have paint dots on them indicating tension? I can't recall off the top of my head, but I think there was a paint color code on the spring like green/purple/red or something. There is also shims that can be added to the spring. Check all of the vacuum lines to the diverter valve and make sure there is good clean passages including the diverter valves functioning.