[SOLVED] Mazdaspeed 6 Not passing 1500psi at WOT

I

Ivanshinoda

Greenie N00B Member
Greenie Member
Hello guys, I have a 2007 Mazdaspeed 6 that can't pass hpfp 1487 at WOT, this is what i've done so far to try to fix the problem:

*switch the whole HPFP borrowed from a friend (I have corksport fuel pump internals in my hpfp in good shape, no scuffs or anything in the internals)

*in tank fuel pressure with engine off ignition on is 54 psi

*in tank upgraded AEM fuel pump

*brand new fuel pressure relief valve (OEM)

* replaced the rail fuel pressure sensor (Bosch 0261545038)

*Installed brand new in tank fuel pump filter

* Engine timing correct (double checked)

* No obstuctions in the fuel lines from tank

Randomly I got DTC P0012, I'm thiking that possibly the intake camshaft is bad, that maybe the lobe that pushes the HPFP is bad.

I'm totally lost at this time, any suggestions?
 
If you google P0012 Mazdaspeed, a lot comes up with some very detailed posts.
<Here> is one from here.
<Here> is one from another place.
Some of the things I saw would be a good basis for a horror story...hope yours is an easy fix.
 
Also I did timing chain job
SyntheticAtmosphere said:
If you google P0012 Mazdaspeed, a lot comes up with some very detailed posts.
<Here> is one from here.
<Here> is one from another place.
Some of the things I saw would be a good basis for a horror story...hope yours is an easy fix.
Click to expand...

I just saw a video from Youtube called ''mazda p0012 CEL DTC cause (for those who tried everthing)'' that basically is a leak from the intake camshaft to the VVT, I removed my valve cover and spark plugs and give it a crank, recorded a video and I have exactly the same leak in the same area, I think I have to replace the intake camshaft, but my I would like to know is if with this DTC P0012 would make the HPFP not raising to 1500+ pressure. I did the PRV test and it only reaches 1311 psi and then go back to 1100psi.

Another thing I forgot to mention is I installed a brand new OCV.
 
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I looked at that other sites thread. While your p0012 is related to that portion of valve timing. HPFP output pressure is not related -- unless the spillvalve on HPFP is bleeding off or PRV is leaking. Is engine running fine if you stay out of boost? So fuel demands are met by the current pressure of HPFP at low fueling demands? If not, then a complete overhaul cleaning of everything in HPFP maybe in order. Getting the fuel system working with pressure at typical max of corksport or auto tech may be issue. The ecu could alter a fuel system pressure drop and then try to change valve timing and that causes the p0012.
 
Thats what I wanted to know, if p0012 is related to HPFP pressure. Car's running great out of boost, fuel demands are met. I compared the HPFP pressures out of boost with my friend Mazdaspeed 3 and are the same. Also, I ran the car with spill valve disconnected and ran great. The AFR's at WOT are 9.0 ish, little rich, but the pressure is what concerns me because I hear that if you go below 1500 psi on WOT can zoom zoom your speed. I will try to clean the spill valve or try another good one and post the results.
 
*SOLVED* It was the fuel pressure sensor, the one that others say that is compatible with mazdaspeed 3 fuel rail (Bosch 0261545038) for me it wasn't compatible because it was reading low and making a noise at cold start, and actually it is physically different. I went to the yunkyard and grab one from a 2007 cx7. The part number is Bosch 0 261 545 006. In the pic I uploaded, at the right you can see the OEM one, looks better. Some people reported fuel leaks with Bosch 0261545038. Also, my fuel tank pressure is reading correctly, the car has more power but still have to fix the P0012.
20230511_210038.jpg 20230511_210105.jpg 20230511_210319.jpg
 
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