just going to put this out there that those on mobile devices typically don't see signatures. I know mine are off and most of my time viewing MSO is on a mobile device.
[SOLVED] HPFP Issue (in-tank pressure)
OK, thanks for the info on that! I was unaware that there was a difference between mobile devices and PCs
I wouldn’t trust the old autotechs that created over $1500 of parts cost last time between troubleshooting and injector cleaning and replacements, so I’m out of luck there. Also, it doesn’t look like spill valves can be found anywhere other than buying a Complete HPFP, but a complete fuel pump unit can be had on Amazon for $120 which would suffice for testing purposes if it absolutely has to come to that.
Also add to the fact that it’s my daily driver, and my income is at the absolute limit already, so I’m trying to pick everybody’s brains that might have testing ideas that might help me to isolate the problem.
i’m a mechanic by trade for the last 15 years so I have a wide array of tools to help me with this, so i’m hoping to avoid throwing 100’s or $1000’s at it worth of parts again unnecessarily unless it comes to it unavoidably.
The main thing that causes me to believe it’s not the internals, is the fact that the pressure is rock solid until I touch the throttle midway through warm up. that’s not to say it couldn’t be the spill valve though.
Also, I read in another thread (which is where I got the wiring diagram) that you should be able to test continuity from the spill valve connector all the way to 2F and 2G at the PCM plug. if that’s the case, that could be my issue right there if the spill valve is hanging open. and again, running jumper wires straight from connector to connector to bypass that part of the harness give worst results and no real pressure other than what the tank pump sends. But this wiring diagram didn’t show if those two wires travel through a relay or not, which could be skewing my results
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have you tried cleaning the hpfp?
https://www.mazdaspeeds.org/index.php?threads/hpfp-o-ring-rebuild-michael-rey-facebook-kit.8069/
we're seeing another user with the same issue
https://mazdaspeeds.org/index.php?threads/help-with-fuel-pressure-weirdness-and-theory.16849/
Yes, I disassembled and cleaned the entire HPFP. My primary goal was to look for evidence of wear and tear or malfunction. None were present whatsoever. I’ve taken it down, cleaned and inspected the pump several times over the years so I’m very familiar with it and there wasn’t a single thing out of the ordinary. I was hoping to find some thing so I would at least have an answer but I struck out.
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Finally got some more time tonight after work for some more diagnostics, and I have continuity from both wires on the spill valve plug, to all 11 wires on the plug on the passenger side of the engine, just in front of the valve cover. This includes the part of the harness that goes to all four coil packs. so I now have that portion of the harness removed and I’ll be splitting the split loom apart to inspect everything next (hopefully in the next day or two).
Obviously, there’s no logical explanation for why there should be continuity here because those wires would all be interfering with each other and a ground also goes through that harness.
Obviously, there’s no logical explanation for why there should be continuity here because those wires would all be interfering with each other and a ground also goes through that harness.