HELP 2007 mazda cx 7 codes p0012and p0304

4/15/23 this all started with head replacement ..car is hard start first thing (starts n dies) five to ten times then when it will stay running on its own it runs like crap.. After it warms up it runs pretty good above 2500 RPMs. Y/M/M: 2007 MAZDA CX & 2.3 turbo mileage: 143793 Location: Grants Pass Oregon. concern: Runnability DTC's: P0012 P0304 Modifications: NONE.. ALL STOCK I have changed the head (refurbished) timing chain, tensioer, guides and gears, VVT hub and actuator solenoid. oil pump, new plugs , cam sensor, crank sensor, throttle body, AND YES I HAVE THE TOOLS FOR CAMS AND CRANK. I've checked the filter in cam cap.. I Have been auto tech. for 38 years and this car is really #$@%^ pissing me off......... HELP!!!

 

Hello and welcome to mso! Certainly frustrating now I'm not tech nor have I ever had the displeasure of having to time our engine but I have seen the error codes from procedure being followed incorrectly @Rokusek has a good how to along with some of the tips and tricks for our engine https://mazdaspeeds.org/index.php?t...eed-3-mazdaspeed-6-cx-7-vvt-the-roku-way.855/

I in reading through other threads I have seen the both the crank shaft and cam shaft sensors fail, there is also a ground wire near the hpfp approx 16awg that's notorious for causing issues if it's not clean and tight.

@L337TurboZ is a fellow master tech, hope he can weigh in more than myself

 

Check the crank position sensor for dirt on the face

 

Replaced both cam n crank sensors

 

Still check it for smutz. They are magnetic and will pick up metal shavings pretty easily

 

same issue here.
mine seems to start and run fine but has a massive hesitation around 2000rpm and super bad fuel consumption
here is my list:
2 different Heads (first one was original and had marks in the front cam journal area not major but there. 2nd was a complete rebuilt item)
2 Different VVT Phasers (new mazda items)
swapped out sensors for working ones
replaced the main harness to the ECU (had some broken clips and dodgy wires anyway)
timing in 100% spot on, didnt even need to wiggle cams to get plate in and chain is tight at TDC.
sanded cam cap to reduce oil leakage on the front of the intake cam.

i've rebuilt afew of these now but never had this issue. i'm now going to pull the intake camshaft and take it to a specialists to get measured to make sure its within spec.

@jamesmzr7 i Feel your pain. i've re-done the timing on this thing like 4-5 times now and getting over it. plus the costs to replace bolts and washers etc.

 

FYI - a couple drives so far after replacing the intake camshaft and the car seems to respond better and fuel economy has improved.. fingers crossed