I have a 1980 Porsche 928s automatic (EURO model) that I would appreciate some help on fuel mixture adjustment. When I bought the car the fuel and air intake systems were disassembled. The the dizzy had been rebuilt and I cleaned all the injectors and replaced all seals. I have reassembled everything, picked an initial tuning for the fuel mixture and got the car started. Here are some videos of the engine running:


I can keep the car running, but if I release the gas pedal the car stalls. It is also backfiring, so I think the mixture is rich. I have made no changes to the ignition timing. I just wanted to know if others heard things that I should consider before I begin making adjustments. Any insight would be appreciated.