Died while driving. Will not start now.

Discussion in 'Mazdaspeed 3 Troubleshooting' started by VashEXE, Jun 30, 2021.

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  1. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    So an update on this. Today I started poking around with the multimeter and didn't find anything immediately wrong. So I decided to hook up the fuel pressure gauge I got to try to figure out where the pressure drop was happening. When I unhooked the fuel lines they were completely dry. When I originally unhooked everything to swap the PCV and whatnot there was fuel in the lines, but it looks like nothing else has made it to the lines since.

    Knowing that I went back to the ITFP and unhooked the the fuel line from it. I came up with this little thing to try blowing through the fuel line to see if there was some sort of blockage or something.
    20210703_165813.jpg

    First try I couldn't do anything, but thinking about that more, that made sense since the PRV would be closed. So I unhooked my fuel line before my 6th port and gave it another blow. I blew out all the rest of the fuel that was sitting in the lines, so there's no blockage. I hooked another hose up to the nipple on the fuel basket itself and had a helper turn the car on to see if it was actually priming and how much fuel was being pumped. When priming a few times, it barely dribbled out. Something is up still.

    I pulled out the basket again and checked the filter, pump and all that. All still looks good. I blew through the nipple on the top of the basket to see if there was any blockage on the internal lines, but that all seems fine too. I'm wondering if the regulator in the basket shat the bed. It seems like the only other part that hasn't been replaced yet and would cause it not to be able to build up enough pressure to actually get fuel out of the tank if so.

    I'm going to see if I can find somebody with a spare or a parts car locally to test, but I'll probably be ordering one of these on Tuesday.
     
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  2. Easter Bunny

    Easter Bunny Professional Engineer Motorhead Platinum Member

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    What does the pressure look like coming out of the pump by itself
     
    Easter Bunny, via a mobile device, Jul 4, 2021
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  3. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    Honestly I'm not sure. It barely trickled out of the line I hooked up to it, but because the pressure gauge I got is requires AN fittings on either side I kinda can't hook it up right at the fuel basket.

    I know throwing parts at it is not the way, but with there being no fuel in the lines up in the engine bay and seeing how weak the priming was, I think it's gotta be something in here. That's the only other thing I can think of at this point.
     
    VashEXE, via a mobile device, Jul 4, 2021
    #23
  4. gotovato

    gotovato Silver Member

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    You check the voltage at the pump when turning the key on/priming the pump?
     
    gotovato, via an iPhone, Jul 4, 2021
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  5. L337TurboZ

    L337TurboZ World Class Truck Squatter Greenie Member

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    Are you getting 12 volts to the pump and less than 2 ohms on the ground circuit?

    You can manually apply power to the pump with a power probe or similar tool. If the pump kicks on then you know it's a wiring or immobilizer issue

    Get one of these kits for testing fuel pressure. It should be easy to hook up to almost any car for future diagnostics if you need to

    https://www.google.com/aclk?sa=L&ai...Qwg96BAgBECo&dct=1&adurl=&cshid=1625423188626
     
    L337TurboZ, via a Motorola device, Jul 4, 2021
    #25
  6. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    When priming koeo I get 12v to the pump. I checked the ground resistance from the harness at the fuel pump to the body of the car and the fuel sensor ground is very close to 0 ohms. The fuel pump ground is more like 2.7 ohms. I'm not sure why just that ground would be bad since the other ground on that harness is good, but I guess it's something to look at
     
    VashEXE, via a mobile device, Jul 7, 2021
    #26
  7. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    Added a ground from the head to the frame the l of the car and when I went back to check resistance it's more like .6 ohms now for the fuel pump ground resistance. Still no start, no pressure. 22psi no matter what. I'm honestly a little lost on where to go from here drive I see it's getting 12v when it would be priming and I verified the grounds look good.

    I bought the regulator ahead of time and already threw it in since it was cheap and of course that wasn't it either.
     
    VashEXE, via a mobile device, Jul 7, 2021
    #27
  8. L337TurboZ

    L337TurboZ World Class Truck Squatter Greenie Member

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    You really need to hook up a manual gauge to the fuel line and see what the actual pressure is and not what the AP/scan tool is reading.

    Also get a headlamp bulb, spade connectors and wires. Strip one end of the wires bare and then on the other side of the wires add the spades so you can connect those wires to the headlamp bulb.

    Next connect the bulb to the fuel pump wires and key the car on. The bulb should illuminate brightly.

    You can have 12 volts present and have a ground wire test good but if the wires can't carry the load then the pump won't output enough since fuel pump pressure and output is based on voltage applied.

    Basically you're doing an amperage test on the wires but using a headlamp bulb instead of a multimeter.
     
    L337TurboZ, via a Motorola device, Jul 8, 2021
    #28
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  9. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    im_back_baby.jpg

    So, after checking the fuel pump wiring with a bulb like @L337TurboZ suggested, it lit up as expected. @Sho sent me some images of a local who actually blew the black fuel line inside of the basket and after talking with @Enki for a bit, that all seemed like a pretty good possibility, so I took the basket out for a 3rd time to check that all out. The black fuel line was fine, but one thing I remembered and mentioned to @Enki was that when I pulled the DW pump out, it required a little tug to actually get it out of the basket. This new AEM just kinda dropped out. After thinking about that for a bit and blowing into the top nipple of the fuel basket, I decided that maybe it wasn't sealing at the top of the basket. I had only put 1 oring on the fuel pump neck which is how the DW pump was configured for over 40k miles before this one. I put a second one on and still could blow through it and it dropped right out... What the hell I'll put a 3rd on... Blew into it and actually got pressure... and a mouthful of ethanol from inside the pump. We're sealed.

    Dropped it all back in and hooked everything up. First prime I heard a shitload of fuel rushing through the line, so I knew we were good. Primed a couple more times and gave it a crank. Started up as expected and fuel trims look good. I am not sure if the original pump actually died or if the fuel filter was just so fucked that it finally choked it all up. That filter was fucked as seen below:

    20210626_211756.jpg

    Either way, I have a new filter, pump, regulator, PRV, and a nice clean hpfp now. The car is running good, so I guess we'll see how that goes.
     
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  10. Enki

    Enki Motorhead Platinum Member

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  11. L337TurboZ

    L337TurboZ World Class Truck Squatter Greenie Member

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    Awesome! Glad it was something mechanical instead of electrical.
     
    L337TurboZ, via a Motorola device, Jul 9, 2021
    #31
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  12. VashEXE

    VashEXE ButtStallion Tuned Greenie Member

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    You and me both buddy haha.
     
    VashEXE, via a mobile device, Jul 9, 2021
    #32
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