once again tonight my g35 wont start after changing out both camshaft sensors, crank shaft sensor, and even the o-ring to my oil filter (which was the main problem why it wouldn't start 3 days ago) I am running out of ideas to what it could be when i turn the car over it cranks for a second and starts cranking slower and slower as i turn the car over. The lights on the dash get dimmer and dimmer as i try to turn the car over..i've also just replaced the battery a few weeks ago and also the alternator when i first bought the car about 8 months ago. Has anyone else had this problem and resolved it? I know one thing whenever the car doesn't start like this and i finally do get the car started it throws out codes for the camshaft sensors...last time it was codes P0345 and P03340 which are both the camshaft sensors... do camshaft sensors tend to fail a lot in these cars? do i need to change both of the sensors at the same time or does that not matter? or might there be another problem that is going on and its just throwing out the camshaft sensor codes...any help would be great..thank you
also i noticed sometimes when id leave the car sit over night or for a little bit and tried getting it jumped or just tryed starting it in general, it would randomly turn over with no problem. im also going to try cleaning the throttle body cause i did notice little rpm drop and raises under 1 rpms at the beginning of engine start up.

 

For the dead battery problem, sounds like you have a parasitic drain and my money is on your radio.

 

^This is probably your complete problem. There's no way your Cam sensors are going bad like that.

Remove your stereo and try driving it for a few days.

 

i'm having the same problem after installing another engine. installed new cam and crank sensors and still wont start. it cranks fine though. im may replace the fuel pump beacuse i read that even though the fuel pump is working, if its not the correct pressure it will cause a no start. have you checked your fuel pressure?

 

Just pull the fuse for the radio. No need to remove the whole unit.

I'm not sure if that fuse is in the cabin fuse box or the one in the engine bay. It may be coupled with the fuse for the fan blower motor.