Cx7 Cranks but no start. Replaced turbo and did timing.

J

Jacob allen

Greenie N00B Member
Greenie Member
So I'm new here and honestly kinda new to the mechanic life but I know a little more than someone with no knowledge at all. So I have a 2007 Mazda cx-7 Grand touring 2.3L and I got around amazingly for the last year, did my routine oil and maintenance, started having issues and long story short I got a new turbo and vvt actuator and replaced my timing chain and tensions. Car set at TDC used my cam alignment plate, did everything correctly, ........or so I thought......Friction washers didn't get replaced and after all was put back together and fired it up, it started and ran but the crankshaft pulley was slipping and and so I went through with tearing it back down and replacing the washers, long story short again.............car wouldn't start. Checked and rechecked and rechecked, come to find out, timing was off because I failed to check when replacing the washers that the cams would roll off that bit of tension release, third time, tore down, TDC, alignment plate in sliding in and out like a miracle, grounds checked, got spark, for fuel.......kinda and will fill in momentarily. Got air but backfiring in the intake and shooting out the throttle body, cranks and tries and tries but no start. Camshaft and crankshaft position sensors replaced, hpfp, replaced, sending unit, was replaced shortly after getting the car but is working BUUUUUTTT I have no codes showing and my Fuel Rail Pressure is sitting at 48 psi Key On Engine Off.

That's where I am kinda lost and still scratching my head now 1 month and a half later. I was getting a normal reading of 300-450 psi koeo and after pulling the hpfp housing and checking alignment again the pressure on the fuel rail won't go past 48 psi. It drops to 42 psi when cranking. Where would I start?? The pressure on the rail is low but I'm getting fuel from the tank but not enough so is it the regulator going out? No leaks that I'm aware of.... Sorry but my brain hurts honestly lol. Kids, school, and my car...... Help please.
 
1 are you sure that the engine is timed correctly? from your description it seems you may have the camshafts 180 degrees out of phase

2 check your spill valve for cleanliness and make sure that you have reattached the ground near the HPFP
 
Easter Bunny said:
1 are you sure that the engine is timed correctly? from your description it seems you may have the camshafts 180 degrees out of phase

2 check your spill valve for cleanliness and make sure that you have reattached the ground near the HPFP
Click to expand...

My exhaust cam was 180° out originally which was corrected, I'm going to remove my VC and make sure my cams are positioned same as in the link when engine is set at TDC. As mentioned my car started after the first go round but I messed up not replacing the washers on the crankshaft and my CAP still goes in the slot with ease last 2x I checked. I will be sure to check my spil valve because I was getting 300-450 psi on the rail with koeo until this last time of removing the hpfp and housing now getting 48psi max.

Raider said:
What he said. Also go read this and make sure you did it right. https://mazdaspeeds.org/index.php?t...eed-3-mazdaspeed-6-cx-7-vvt-the-roku-way.855/
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Lmfao these are close too but not the same instructions I used when doing it the first time, I can say I may have skipped the washer replacement part but other than that I feel I was pretty spot on with the whole process. BUT I'm going to do it all over again and make sure not to miss a step what do ever. And my ground by the HPFP is connected and I've made sure it was everytime. It's got spark and WAS getting fuel but now the fuel is lacking but I feel as if I had proper fuel I'd be golden right now.
 
Last edited by a moderator:
Our motors are interference motors so you may have bent a valve if cams were out 180 degrees.
 
Ok so went ahead and changed out my hpfp and housing, also changed the fuel rail and my psi went from a whole 8psi KOEO to 52 psi. Car still won't start and I have verified spark, fuel tho on the other hand.......could it possibly be the pressure sensor? How do you correctly test the pressure sensor? Also sitting with no codes at all and I'm kind of lost on my next step as I am a month into this headache after doing the timing and replacing the turbo. Checked grounds and connections which are all nice and tight. HELP ME!
 
52 psi is basically tank pressure your hpfp isn't doing anything
 
Easter Bunny said:
52 psi is basically tank pressure your hpfp isn't doing anything
Click to expand...
Ok I replaced the HPFP, and still only getting between 40-50 psi FRP. When trying to start the car it won't budge past 40-50psi either. What would be my next step because I am at a loss. TIMING was redone again to make sure I had it all lined up and everything was step by step done and I am confident with my work on that but now this fuel issue I'm having is making me want to just give up. Going on 2 months with this mess since deciding to replace the turbo and do the timing. It started after doing the timing the first time yet I didn't replace the crankshaft washers which the crankshaft pulley was slipping due to not changing it and after redoing the timing again, and again, and one last time for the hell of it, then I come across this low fuel rail pressure and have been unable to diagnose the issue causing it, which in turn I've been walking quite a bit lately.
 
Easter Bunny said:
So you replaced the spill valve as well?
Click to expand...
I mean the spill valve is part of the high pressure fuel pump is it not?
Easter Bunny said:
So you replaced the spill valve as well?
Click to expand...
I replaced the whole HPFP, splll valve and all. i am going to check my voltage with key on to my pump because it seems like its doing nothing or my rail isnt gaining any pressure like the relief valve is stuck open but if it hasnt reached the pressue to need to open since the car hasnt been ran then how could it be stuck open. Didnt get the low pressue til after doing the timing and everything and the only thing fuel related i touched was the hpfp housing to get to my cams for the alignment plate. idk if i shoukd be testing the sensor, clog somewhere or relief valve. i need a fuel pressue tester kit but im unfortunately low on funds due to being immobilized. This is really starting to irk me. Wiring maybe?
 
Jacob allen said:
I mean the spill valve is part of the high pressure fuel pump is it not?

I replaced the whole HPFP, splll valve and all. i am going to check my voltage with key on to my pump because it seems like its doing nothing or my rail isnt gaining any pressure like the relief valve is stuck open but if it hasnt reached the pressue to need to open since the car hasnt been ran then how could it be stuck open. Didnt get the low pressue til after doing the timing and everything and the only thing fuel related i touched was the hpfp housing to get to my cams for the alignment plate. idk if i shoukd be testing the sensor, clog somewhere or relief valve. i need a fuel pressue tester kit but im unfortunately low on funds due to being immobilized. This is really starting to irk me. Wiring maybe?
Click to expand...
Fuel rail pressure relief valve has been replaced and still not getting pressure beyond, we will say 50psi as the median number and drops to 43 when cranking. So we have new turbo, new hpfp, relief valve, new crank and cam sensors, timing chain, vvt, tensioners, map sensor, battery, relays, fuses, and in tank pump with sending unit. Wtf am i missing?

The car will crank and you will hear spurts of what sounds like the motor trying to fire off, but since doing the timing the first time and starting the car first turn of the key, then having to redoing the timing to replace the crankshaft friction washers the next day, I've have had absolutely no luck with anything. Tested voltage at plugs and continuity to most all parts related to the issue and everything seems golden. Grounds are all snug and everything has been disconnected and reconnected........

I'm tired of starring at my car dreaming of the day I'll get to drive it again....then come the visions of me looking into a ball of fire in my garage where I have just thrown up my arms and lit it up.

Seriously considering it because over spent more money and time on this car recently than I ever imagined.

Sorry for the rant but I don't get to talk about my car issues at home..... Lol
 
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