A friend wants to borrow my compression guage and has asked for my assistance in doing the test on his BJ7. It has been years since I used the guage. I think I remember the procedure: 1. warm engine first, 2. remove all spark plugs, 3. remove coil to distributor lead, 4. fully depress trottle while turning engine over for each cylinder test, 5. record results. Any low compression cylinder should be at least 75% of the rest. Two low cyliners side by side suggests head gasket leak. Question? Would it be advisable to disconnect the power to the fuel pump while performing the test?