Car won't start

Mxer4life

Mxer4life

Greenie N00B Member
Hey guys, having some issues with my 2010 ms3.
So I recently had a failed pcv valve which covered everything in oil and had to replace it. Ever since then the car will not start. It turns over and will occasionally get one little spit like it wants to start but it doesn't. Fuel pressure is around 70psi before cranking and peaks around 83-95psi when cranking.

It makes spark, bled the fuel system 3 times now, tore apart the hpfp to deep clean everything (did it twice. First time only did the plunger and spring, 2nd time I tore it down to nothing), cleaned all wire connections, and no codes are being thrown. Compression/leakdown tests looked good, too. Except cylinder 3 is leaking slightly from the exhaust valves but still makes 135psi (porting and polishing soon with upgraded springs and titanium valves so I'm not too concerned with the leak aside from it being a freshly rebuilt head).

I had a similar issue when I rebuilt the motor and put everything back together but one day it just started up and never had an issue again until now (about 10k miles since rebuild).

Any leads would be great. Until then I'm tearing it down like I had it when replacing the pcv valve to check if I missed or accidentally disconnected something.
 
Silly question, your throttle body wire is connected after cleaning it all up and MAF plugged in? I only asked because I've been caught myself by the throttle body being unplugged.
As for the pressure relief valve you Should be able to blow one way through it not both directions, probably not your problem since car won't start usually it's more of a stumble while driving but fuel pressure seemed a little low during cranking. Usually weird issues like this is a ground not connected.

One way to test prv which doesn't really help if car won't start...
One way to check doesn't help if car won't start:
Template public:_media_site_embed_youtube not found. Try rebuilding or reinstalling the s9e/MediaSites add-on.
Cheap replacement if it does blow through both directions https://www.tascaparts.com/oem-parts/mazda-fuel-pressure-valve-l3k9132j0
 
Awafrican said:
Silly question, your throttle body wire is connected after cleaning it all up and MAF plugged in? I only asked because I've been caught myself by the throttle body being unplugged.
As for the pressure relief valve you Should be able to blow one way through it not both directions, probably not your problem since car won't start usually it's more of a stumble while driving but fuel pressure seemed a little low during cranking. Usually weird issues like this is a ground not connected.

One way to test prv which doesn't really help if car won't start...
One way to check doesn't help if car won't start:
Template public:_media_site_embed_youtube not found. Try rebuilding or reinstalling the s9e/MediaSites add-on.
Cheap replacement if it does blow through both directions https://www.tascaparts.com/oem-parts/mazda-fuel-pressure-valve-l3k9132j0
Click to expand...
Maf sensor and throttle body wires were the first things I checked. I've made that mistake before. Happens to the best of us.

It does sound a lot like a ground wire to me, only issue is that I never unbolted any of the grounds during the pvc valve replacement. I unbolted the plate that the coil pack harness plugs into and laid it over top of the tmm while I took off the manifold. Also, only unbolted the throttle body from the manifold and moves it just enough out of the way. So if it's a ground wire then I have no clue how it happened. But everything is pointing towards a bad ground somewhere.
 
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