[SOLVED] Randomly loses fuel pressure

Year/Make/Model: 2008 speed 3
Mileage: unknown rebuilt by previous owner
@Roger Mesler
Location: ohio
Concern: loses fuel pressure when throttle is inputed, doesn't make correct fuel pressure at idle
Modifications: hpfp upgraded Internals, bnrs3 turbo, 2 aem fuel pumps and inline filters, it has a fuel cell because it has been converted to awd, front mount intercooler, Manley H beam rods and weisco pistons

ECU/Tuning Software: Cobb Acessport
Tuner: Freek Tune 93 bnrs3 (base tune)

Recent Repairs: tried cleaning the hpfp Internals and the sensor on top

 

Have you tested the pressure relief valve?

 

I really need to put Sho's prv video in a fueling troubleshooting how to thread

op here's how to test your PRV, with engine at temp

 

Feel like you are repeating yourself....repeating yourself? LOL

 

I just put a new prv on it and still having the same issues

 

Did you ever test the old prv to see if it was bad?

 

No, just bought a new one because with minimal fuel pressure I don't want to run it long enough to warm up, and bought a new one

 

Did you use an oem sensor and replace the entire rail? Is the one on there now working correctly?

You could have idled for as long as needed on the old one.

 

It was hard to get it to start on the old one replaced the prv and the new one doesn't seem to want to start but it will randomly go up to 500, 700 and 1000 psi on different start up attempts most of the time it is in the mid 60's

 

mid 60s is the in tank pressure only, something is wrong with the HPFP

 

Sometimes it reaches more than mid 60's which is why I'm trying to narrow it done to something before I throw a HPFP at it.

 

Seems worth pulling your hpfp and giving it a cleaning / service and inspecting it for scoring
https://mazdaspeeds.org/index.php?t...nd-spill-valve-michael-rey-facebook-kit.8069/

 

Try Read this. You might understand better how the HPFP works and therefore what the issue could be.

 

Fixing the hpfp doesn't necessarily mean a whole new one. Most of the time a good service will get it back to working order

 

I took the pump apart, the retainer clip that goes above the spring and holds the keepers, Is there a website where I can get a new one
Mine got lost in the disassembly process

 

Did you ever figure out your fueling issue?

 

HPFP needed rebuilt runs alot better now


SOLVED