Another month goes by, no troubles until, it develops a random hard start condition. Completely random, but by letting the fuel pump run a bit before I turn the key to start, it usually starts. Drive it until it's a constant hard start problem, then put a fuel pressure tester on it.
Test- Connect pressure gauge to the Schrader valve on the fuel rail.
At the Data connector, ground the fuel pressure test terminal. This makes the pumps run constantly when the key is on, unless you have a wiring problem.
Turn key on and listen for constant pump operation, high pressure, and in tank, (switch tanks and check both). I'm reading about 30 lbs, and it drops instantly after shutting the pumps off. I know the in tank pumps are working at this point. Checked for kinked or broken fuel lines, checked filter, all good.
Preformed Fuel Regulator underpressure test- Same as a pressure test, but done with the fuel return line blocked downstream of the FPR. If pressure rises substantially, the FPR is bad.
Pressure does not rise. Which indicates a bad pump. But, more testing is needed, because it failed the Engine off Static Pressure test as well.
Knowing my high pressure pump is weak, I change it first, and re test.
With a new pump, pressure is within spec, which calls for 35-45 lbs. And as a bonus, it passes the static pressure test, which calls for pressure within 5lbs of spec, for 1 minute after shutting off the engine.
I should note here, I installed a Napa pump at first, but it was incredibly noisy. After 3 pumps, my Napa store returned my money, and I bought one at Auto Zone. This was in late 2009, product lines are surely different by now.
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