I have a 96 Yukon 5.7 litre. Ever since i've changed the fuel pump i've had a drop in my range. I've lost close to 150 km on a full tank. I've replace cap, rotor, plugs, air filter, fuel filter, O2 sensors and had the fuel injectors cleaned. I did a fuel pressure test on it and it reads 64 with key on motor off. With motor on it reads 54. Both are withing specs according to the manual. After i turn off the motor the pressure steadily drops over five minutes by about 14 psi. This is outside the normal specs. The book sais I have a leak some where. There is no fuel dripping anywhere. The return line isn't kinked. So i'm figuring maybe it's a bad regulator? Anyone know how this part swaps out? Is it a staright forward job? Any tips would be appreciated. With the price of gas it would be nice to get my range back. Thanks