Two out of three problems fixed on 911.
 

Over the past days I replaced the intake gaskets on the passenger side because of large leak. I also replaced the copper air tube that runs in the back of the motor to the throttle body. I had three problems, very rough start where the idle would not catch and very rough idle. The third problem was a mis under a load. After the vacuum gaskets were replaced the idle and starting are back to normal. But I still have the misfire while driving on neighborhood streets. I have changed plugs, wires, cap, rotor, fuel filter, valve adjust, all vacuum fixed. I as thinking injectors but it starts and idles so nice. I will fix this. I fixed the other two . Maybe I need to re visit my valve adjust. What do you think? Nick

What sort of 911 and engine?

1985 3.2. After the vacuum problem is fix d I’m thinking is must be electrical. I think if it were injectors it would run terrible at startup and idle. I think it may be time to have a look at the afm arm adjustment.