Dipping fuel pressure/won't boost past 10psi

Discussion in 'Mazdaspeed 3/6 Engine' started by Wannabemekanik, Apr 13, 2021.

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  1. Wannabemekanik

    Wannabemekanik Greenie N00B Member

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    Hey guys, first thread post so sorry if there are any mistakes.

    Just recently installed "Relentless" Ported intake mani, intake mani TIG, DM full EGR delete, CS injector seals, gen 2 valve cover with breather cap and turbosmart BOV VTA. Immediately got a base map from Jason at Dizzy, ever since then I've been getting fuel dipping to 200-300 psi at around 4k rpms and boost won't past 10psi.
    I've been at this for weeks And I can't find a solution. Pls help...
    I've done a compression test as well and all cyls were over 150


    I think I'm officially FBO now on stock K04
     
    Wannabemekanik, via a mobile device, Apr 13, 2021
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  2. Duey1083

    Duey1083 Greenie Member

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    Sounds like it could be your fuel pressure relief valve stuck open or your spill valve in the HPFP.

    How many miles on your car and when is the last time you serviced the HPFP?

    Do you have any datalogs of the condition?

    EDIT: you mention you've been at this for weeks. What have you tried so far to fix the issue?
     
    Duey1083, via a Samsung mobile device, Apr 13, 2021
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  3. Wannabemekanik

    Wannabemekanik Greenie N00B Member

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    First problem I had after doing those mods was a Cyl 4 misfire, so I replaced all sparkplugs, coilpacks, stretched coils, fuel injector on Cyl 4, fuel rail, compression test and vaccum leak test. Still had a misfire, so my last resort was to replace the fuel injector wiring harness, which, turned out that was the problem.
    I just hit over 64k miles, Hpfp internals and almost all other boltons were done at 55k. Never used any other fuel but 92 oct in Hawaii.


    I do not have any datalogs to provide atm...
    And I am not getting any CELs and I have also tried switching tunes to a base map from stratified but that didn't do any difference.

    I did notice that I don't hear the normal priming sound from the Hpfp anymore, pressure builds up (KOEO) to 50ish psi and starts up normally. I just don't hear the normal whine of the prime. It's quiet...
     
    Last edited by a moderator: Apr 13, 2021
    Wannabemekanik, via a mobile device, Apr 13, 2021
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