09 g37x won't start
 

Hey guys, I’m new here, not sure if I’m doing this right but I need sum help! I’ve had my G for 7 months, was on my way to work and it started to shutter, not accelerating and eventually shut completely off. Wouldn’t start back up but it was definitely trying.. I replaced serpentine belt, 6 spark plugs, 1 ignition coil (5 more will be here tomorrow) a new battery, 1 crankshaft position sensor and 1 camshaft sensor.. still the same thing.. I checked my fuel pump, seemed fine thought it might be clogged.. I’m not a mechanic so I put it back… has anyone experienced something similar to this because I don’t know what’s up.. thanks

Wow... that's a lot of parts and money to throw at a problem.
You may want to scan for codes (even if the check engine light is off) as it may give a hint to what is going on.

From what I have seen, most of the time a crank/no start is caused by a problem in the cam/crank position correlation.
This can be caused by a bad crank sensor, bad cam sensors, or the mechanical timing (slipped cam encoder ring)

Note: some of the cheaper ebay/amazon crank/cam sensors don't work properly.

Definitely a lot of money for nothing seems like, at least I have new parts once it’s running.. anyways update time.. I put the new ignition coils on today, it did start up and idle rough.. bigger improvement than before.. I already swapped out a new cam shaft and crankshaft sensor.. now im thinking it’s the fuel pump..

Based on what?
Are you just going to reload the "parts cannon" and keep guessing?

the reason I guessed that was because I looked up the issues online and in the forum and they’re saying try sensors and all of that first.. after it started today I pumped the gas a few times to rev it up and then it idles rough and cuts off ..Since I’ve changed sensors that was the next thing

I understand... and unfortunately so many people are trying to fix their car this way... by googling.... guessing and hoping.
This can be very expensive as you spend money on parts you don't need.

The other option is to look at the fuel trims to evaluate the fuel system using a $15 ELM327 and a few different free apps.
This will also show you the misfire count by cylinder, measured air flow through the MAF and intake manifold vacuum.
These are all key indicators to sensor and mechanical health.

You can also look at the fuel pump current draw/waveform or measure the fuel pressure directly. (hint 52 psi)
There are even ways to verify each individual coil and fuel injector, and pin point which one is bad without taking anything apart.

I am trying to help you and save you money on parts you don't need.
Here is what you have replaced so far:
• serpentine belt
• 6 spark plugs
• 6 ignition coils
• new battery
• 1 crankshaft position sensor
• 1 camshaft sensor (by the way, the G37 has 2)
• and maybe a new fuel pump.

The point I am trying to make is to stop guessing and start testing & diagnosing the problem.
If you don't have the knowledge/skills to do that, take it to a shop that does.

I've worked on cars for 40+ years and specialize in advanced electronics, netwoking and diagnostic training.
If your car was in my garage, I could tell you what is wrong in 15 minutes.

I wish you the best of luck on your next part fixing the issue.