CIS runs badly when warm up
 

My 79' 911SC runs poorly when up to operating temp. I suspected the freq. valve and the sensor plate. When the car was cooled down it ran well but when warm I have to pump the gas and floor it to get it to run, then it only runs well above 4K RPM. Should I look now at the WUR?

Mike

cis
 

There has to be someone in your area that has a set of fuel pressure guages that can test the fuel pressure both hot or cold. It sounds like a chech valve problem.

If you're going to try to deal with it yourself you MUST have CIS test guages. Otherwise youl'll be replacing the wrong parts. It's the best investment you can make.

Forgot to mention that you'll also need a Bosch CIS book.

Sounds like the WUR. You can check the warm control pressure w/ the gauges the others have mentioned.