Just wanted to add to the growing content in this group for do-it-yourself mechanics. I became frustrated trying to find a way of testing the fuel pressure of my 1.5L honda DPFI (throttle body). The bolt size of the "service bolt" on the fuel filter is 6mm. I couldn't find a way of adapting to this port with the fuel pressure tester that I had short of ordering a very expensive Honda part that would be two weeks out. Hence, I went to the wrecking yard and got a made-up fuel line that goes from the the filter to the throttle body. I cut this roughly in half and installed a 1/4" barbed "T" with a threaded hub (came in the Pressure test kit). I replaced the original fuel line temporarily with the test line and installed the pressure tester. I placed a two-by-four across the engine compartment and under the hood, snaked the pressure test guage under the hood onto the windshield and drove the car around the block a few times and observed the pressures on the guage...when I accelerated the guage pressure would decrease. Would someone please explain the relationship between pump pressure, regulator pressure and volume of gas used associated with acceleration? Thanks, Tich