This exact symptom has happened to my wife very sporadically. Finally happened when I was around. It was strange- Whirring when key turned on and dead silence when turned to start. Was very repeatable for the 3 minutes it was occurring- that was 1 month ago and has not happened since....Dead silence from everywhere except my cursing.
Any suggestions where to look? Does anyone have a wiring diagram so I can test the wiring going to the pump? Any way I could ohm the pump assembly itself?if you didn't see either of the 2 common signs of that failure; one of the 3 tabs on the cap cracked, or, a displaced/'ruptured' O-ring , then I think you need to look elsewhere. I suppose there is some slim possibility the o-ring has become hard and is not sealing, but that doesn't seem to have been reported.
Where are you measuring the pressure (e.g., before or after the fuel filter in the engine compartment)?the fuel pressure builds slowly when trying to prime
Correct on the measurements at pins 1 and 2, although I haven't found a spec for the resistance through the pump motor.
Where are you measuring the pressure (e.g., before or after the fuel filter in the engine compartment)?
Once it reaches 20 psi during priming, does it hold that level (engine off), or decline, and if the latter, how fast?
I will definitely try a different relay. However I did pinch off the return line and pressure still never went over 20psi. Still think maybe a regulator?maybe swap a different relay in if there's another compatible one in a different system
one idea, after you confirm voltage and good ground connection, not sure what it may lead to, cycle the key from OFF to ON several times without starting. See if you can build pressure higher than 20. Then, maybe clamp the lines off and try again.
If it just can't even build the pressure after clamping the lines and the power is good and there's no leaks - I see no reason not the try a new pump.
but, if pressure can be built, maybe there's a leak underhood somewhere? Fuel Pressure regulator or an injector or ???
I have this in my 2001 outback. Works amazing. I made a post about how I thought it was a much better design to be held on with screws. I believe airtex makes them for carquest/advance auto but not positive.Looking at the available aftermarket fuel pump assemblies, I noticed the Car Quest branded part (which appears to be a re-branded Spectra Premium brand part) has a metal reservoir cap which is retained to the plastic body by screws, rather than the "C" shaped tabs as on the factory cap. Has anyone bought and tried this style assembly?
I assume you were referring to my 20psi. The fuel filter was just changed when this happened. It was right after I finished my HG. Didnt matter what I did. I disconnected vacuum to regulator. Pinched off return line. Nothing changed the reading. The new car quest filter fixed it right up. I was also getting a lean code since it wasn't enough fuel.When was the last time the fuel filter was changed?
Have you checked the pressure before the fuel filter?
A reading of 20 PSI could easily be a clogged fuel filter, from memory they are scheduled to be changed every 25,000 miles (but they are often overlooked).