Hi Everyone,
My ‘05 Coupe 5AT has a seemingly ambiguous issue starting which began out of no where. I recently road tripped this car 4000 kilometres without a hint of issue from the car, but when I went to start it the other day, it hard started, ran horribly for a second before I instinctually turned it off in an attempt to prevent potential damage. Today, the car turns over, may cough a very hollow sounding fire here or there, but will not start. I plugged in my OBD reader and it’s not throwing any codes.

I’ve done basic checks, but I’m hoping this sounds familiar to someone. My research and the service manual point to a number of potential causes and I wasn’t able to find any existing threads with identical issue. Battery seems fine as it cranks normally and I wasn’t able to find a bad fuse or loose connections. I can hear the fuel pump prime and turn off as usual when I turn the key on. My security light also turns off as per usual when the key is in the vehicle. My other two keys produce the same result. First thing I’m going to check is for spark.

Any advice is greatly appreciated

 

Firstly I'd pull the spark plugs and inspect. I suspect you had a cam sensor die. While cranking does your tachometer move? I suspect it will.

 

Update: the car has sat for a week while I did research and it managed to start today. Slapped the code reader on and snapped as much data as I could. A slight rev after it hit operating temperature caused it to stall. Oh and the taco doesn’t move when cranking. Still no code

 

 

Was the tach functioning properly when it was running for that short while? I still suspect a failed sensor, intermittent crank sensor failure it sounds like.

 

Here’s a video of the start and stall
G35 hard start, stall issue

 

Crank sensor. The best practice is to replace the cam and crank sensors at the same time. When one goes the rest aren't far behind. Only use Hitachi.

 

Thanks for your replies. I ordered the hitachi CPS0006 from rock auto. Should be here in a couple days. I’ll post the outcome.

 

Good news, crank sensor solved the problems. Car is running normally now. Thanks for the replies

 

That is great news. When your camshaft sensors go bad don't forget to replace all of them at the same time.