Thanks for your help so far. Just put an oil pressure tester in place of the gauge. Start up this time 72psi, fan cut in at 88deg c when it was 16psi and at 90ish it went down to 13psi, so slightly better. (the dial on my dash gauge is non linear so that might explain variation) Even so it falls short of Cosworths guide of 24psi at warm idle. Any experts got a definitive list to work thru? Will first check gasket (thx Alvyn) then blow thru strainer and pipes. Pump brand new and standard by the way.