Mazdaspeed Forums

Mazdaspeed Forums (http://www.mazdaspeedforums.org/forum/)
-   2010 MS3 - Troubleshoot/Diagnostics (http://www.mazdaspeedforums.org/forum/f436/)
-   -   fuel pressure dropping to 200psi (http://www.mazdaspeedforums.org/forum/f436/fuel-pressure-dropping-200psi-203577/)

boatis 07-09-2016 03:58 PM

fuel pressure dropping to 200psi
 
2 Attachment(s)
my car threw a P064D code. i took a 3rd gear log (WOT from 3500-4500RPM) and fuel pressure is dropping really low (~200psi) and AFR is pegged at 14.85. i've had CS internals for ~20-30k miles now and never cleaned them. i occasionally run an e30 blend but have mostly been running 93 lately. any help would be much appreciated

edit: the P064D code usually goes away after a day or so if i dont go WOT, but immediately returns once i go WOT

sheston 07-09-2016 07:35 PM

With the AFR not changing, sounds like a bad O2 sensor.

As far as the fuel pressure, you could try cleaning the spill valve and see if that helps. To me it doesn't look real. You are getting over 2 load with no KR. I would think if the pressure was that low, you would knock

Have you don't anything to the car recently? Forgot to plug something back in? Forgot to reattach that ground by the HPFP?

boatis 07-11-2016 03:03 PM

1 Attachment(s)
Quote:

Originally Posted by sheston (Post 3068188)
With the AFR not changing, sounds like a bad O2 sensor.

As far as the fuel pressure, you could try cleaning the spill valve and see if that helps. To me it doesn't look real. You are getting over 2 load with no KR. I would think if the pressure was that low, you would knock

Have you don't anything to the car recently? Forgot to plug something back in? Forgot to reattach that ground by the HPFP?

haven't done anything recently. the last thing i did was a catless downpipe and dyno tune last summer.

here's a log of when the check engine light turned on. no CEL before the pull and it turned on halfway through the log which is what makes me doubt that its an o2 sensor problem, because it was working fine until i went WOT

sheston 07-11-2016 05:24 PM

That log looked better, until you get about half way thru it. AFRs go to straight line. The P064D code does look like it might be related to O2 sensor, but....

Did a quick search and saw where someone changed their spark plugs when they were having this issue and it cleared up. Might be worth a try. Otherwise, check your wiring harness, most likely around the ECU, and look for rubbing or shorted wires.

boatis 07-13-2016 08:53 AM

Quote:

Originally Posted by sheston (Post 3068620)
That log looked better, until you get about half way thru it. AFRs go to straight line. The P064D code does look like it might be related to O2 sensor, but....

Did a quick search and saw where someone changed their spark plugs when they were having this issue and it cleared up. Might be worth a try. Otherwise, check your wiring harness, most likely around the ECU, and look for rubbing or shorted wires.

i'll be doing the spark plugs today. we'll see what happens

boatis 07-13-2016 02:46 PM

2 Attachment(s)
spark plugs fixed it !


All times are GMT -7. The time now is 02:25 PM.

Powered by vBulletin® Version 3.8.6
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
SEO by vBSEO ©2011, Crawlability, Inc.
vB.Sponsors

©Copyright 2008 ; 2019 Cymru Internet Services LLC | FYHN™ Autosports HQ
Ad Management plugin by RedTyger

Page generated in 0.17022 seconds with 11 queries