Here is what I did. The pump I had in the car was a repop. The pressure regulator in it was not one that could be modified as it is a new redesign. This pump did not function at low idle below 1800 rpm. I pulled out an old pump I had. It had the same problem, it also had a small leak at the front shaft. I used it as a test and pulled out one shim from the pressure regulator on this pump and reassembled/installed. This pump worked great at all rpms ranges after removing one shim. Now just waiting for a new seal kit...
