Bogs down at 3000 RPM in most gears, and now backfiring.

[Bill Douglas]

Unlikely, but worth a try.

My SC had a miss for years. It got worse when the car was hot. It turned out the plastic cover in the distributor. Flat thing under the rotor to stop crud falling into the works. Was rotated or misplaced or something, causing the distributor cap to not be correctly seated. I guess it made it too high on one side and not a good enough contact for the rotor to send a current to certain plugs.

[fizh]

Welp, I can't justify spending 10k minimum to replace a head stud with no additional upgrades, other fixes, etc. Just the bare minimum to get me back on the road.

That said, I will be spending Thanksgiving week and likely December holidays doing it myself. I will likely start a thread in the engine rebuild forum with progression details, questions, etc.

[premdes]

I love these posts. , have had same issue for a year. Took it to a Porsche shop they never solved it and charged me all kinds of fees and send me home. I have changed fuel injector seals, spark plugs, valve adjustment, cleaned WUR and all ejectors, replaced fuel filter. And nada

So reading this thread with so much knowledgable people inputting things to try is wonderful.
Keep it going guys. More of us are suffering from the same 911 ailments than you know

[gwmac]

Had similar problem , it was the coil.