0V HPFP randomly dies

Hey all,

I'm new to the site so sorry if this has been asked before. ( i searched and couldn't find anything.)
My 2009 Mazdaspeed 3 is having issues with randomly cutting or losing hpfp pressure, and crazy FT. I randomly get P2178/P2188 at least once a day. My fuel trims will go anywhere from -20 to +20 even while idling.

I have 0v at my HPFP sensor. It builds pressure fine all day but it will drop to 0 and stay at 0 for about 1 minute then go back to normal.

MODS LIST
FMIC
AP V3
Cobb intake
stock turbo k04
CS Injector seals/New injector o-rings OEM
New PCV valve OEM
New spark plugs 1 step colder

I ordered new MAF sensor OEM, New o2 sensor OEM, New MAP sensor OEM. I also ordered new coilpacks, new recirculation hose.

I will randomly lose all power, HPFP drops to 0 PSI. 0V HPFP sensor is constant, it never reads any voltage.

Thanks in advance for any help.

 

@Enki

Stop buying new parts. There is something up with the hpfp

 

Let's see an idle log of the issue please.

 

I purchased the car used, and it has crappy generic parts. I am replacing all with OEM hence all the new parts i'm buying. I will post a log as soon as i get home.

Anything in particular i should be on the look out for? I was told by previous seller it has autotech HPFP internals. I do not believe him after seeing all the other cheap parts that were on the car. Fuel pressure maxes out at 2025

 

You have to pull the internals out of the pump to know. There's no other way to tell.

 

Yep. Pull the hpfp and open it up to check.

https://blog.edgeautosport.com/hpfp-internals-upgrade-for-your-mazdaspeed-3-and-6 - Autotech internals look as Alan and JP have posted here.
https://corksport.com/mazdaspeed-high-flow-fuel-pump-internals.html - Corksport internals look as CS bros have posted here.
https://corksport.com/support/instructions/Gen-6-999-WEB.pdf - instructions if you need help getting everything disassembled.

 

Hpfp voltage reading zero is normal.

Sounds like your fuel pump resistor may be unplugged or bad.

Its in the driver side frame rail under the intake. Looks like an HID ballast. If its plugged in, unplug it and jump the connection. If it stays running without the pressure dropping and the far dying thats your issue. If its currently unplugged, plug it in

 

Okay i will check once i'm off work.

I data logged yesterday but was unable to upload as i left my computer at work. I will get it up asap. I just got another code P0192.
Someone told me it might be my fuel pressure sensor, but it was fine before i replaced the injector seals with the CS seals. There was oil on my injectors when i removed them. My next move is to remove the HPFP and see the internals, maybe the o-rings. I will be ordering the CS internals to replace the ones i currently have regardless as i'm not so fond of the work that has been done to the car by the previous owner. Whenever i drive regular no WOT the car runs good, but WOT it stumbles, and struggles to get past 5k rpm.

I will check that resistor, but i believe seeing it and it looked very corroded. Would this cause bad fuel trims?

Again, thanks so much guys i appreciate all the help.

 

If you're in the checking pump or Swapping internals "just because" may as well also get the CS hpfp rebuild kit and put in new o-rings etc and clean up the pump everything needed for that is here
https://mazdaspeeds.org/index.php?threads/hpfp-o-ring-rebuild-michael-rey-facebook-kit.8069/

Plus CS has their own instructions which are good too.

 

Hey guys I was finally able to upload my data log. I attached some of me driving to work, and some of me idling.

 

Looks like a car with a stock HPFP to me. Make sure you have Accel pedal position in your logs in the future; best to turn on everything for logging and let your tuner tell you what to omit, but for general troubleshooting like this, have EVERYTHING on.

 

I'm not sure how to set things for my AP to log. What do you mean by everything on? Also, that's what i figured so i ordered a CS HPFP Internals and O-ring rebuild kit.

Sorry if this is a dumb question. Just trying to learn how this AP works.

 

Okay, so now i'm really stumped here. I'm still having the above mentioned issues except as of today my car will not hold pressure with the engine off and key on. As soon as it turn off the pressure drops to 5PSI. I have to crank the car for about 5 seconds then stop and crank again to get it to start. I'm not sure where to begin. I read from CS that it could be a bad in tank pump, in tank pump filter, fuel pump relay, or wiring. What do you guys recommend to try first?

I have new HPFP Internals arriving next week, and i'm thinking of just upgrading the in tank pump while i'm there. Any recommendations?

 

Go into settings and select log parameters you can select what you want there.
Can probably use one of of the e85 in tank pumps

https://www.freektune.com/collections/mazdaspeed/products/aem-e85-high-flow-in-tank-fuel-pump-340lph