[AndreasK]

Hi. Recently bought a 77 911S. Has the original 2,7. Rebuilt some time ago, with SSI headers and 964?? cams. Sweet car and engine. Starts and runs great when warm.

Starting cold, not so good. Very predictable, but, I have to give it some throttle and it fires up. Wonīt idle for about a minute. Shuts right of. With the throttle i can keep it steady at 1000 rpm. After about a minute, with the same amount of throttle it suddenly (takes about 5 seconds) revs up to about 2000 rpm. I can then let the throttle go and it idles fine. Rides a bit jerky until fully warmed up. Especially around 2000-2500 rpmīs. Some backfires, especially when changing gears at lowish rpmīs.

Porsche shop, checked fuel pressures, when i bought it. Not so good. Changed accumulator and fuel pump. Pressures fine after.

Where do I start looking?