Need Help in dignosis: 2004 Infi G35 - First misfire, Now won't start
 

Hello Guys,

I am new to this forum and first time infiniti owner. I got 2004 G35 automatic 3 months ago with 127k miles on it. the car was in good condition before it ran low oil (I failed to notice: My ignorance) and I had to replace Valve cover gasket and MAF sensor.

Now after 1 month of the replacement, it started misfiring. I checked the code with OBD2 and it was P0301 Cyl 1 misfire. I didn't drive the car after I read the code for 1 week (waiting for spark plugs to arrive) and thought of replacing all the spark plugs first. Before my spark plugs could arrive, when I was trying to start the car just to make sure everything else was fine, it wouldn't start! I went ahead and replaced all the 6 spark plugs when they arrived and it still WOULDN'T START. It is cranking, battery is fine but would fire the engine. I knew 1 spark plug or 1 ignition coill wouldn't prevent the entire 6 cylinder engine from starting. So I checked all the fuses, fuel pump.. they seemed working. Then checked whether the spark plug was sparking by taking it out of the engine.. and it DIDN"T SPARK (Checked 3 spark plugs)! So I am certain that there is some electrical problem that is not letting the sparkplugs work.

Kindly suggest any other diagnosis methods so that I can pin point the problem area. Also suggest if there are any other possibilities that can cause the car not to start.


Thanks,

Sanchamp411

Follow the troubleshooting steps in the FSM

Did you check for a blown fuse if you are not getting spark?

http://www.nicoclub.com/FSM/G35/Sedan/2004/ec.pdf

See page EC-133, 307

http://www.nicoclub.com/FSM/G35/Sedan/2004/sc.pdf

See page SC-9, SC-15

Good luck

Telcoman

Hello Telcoman,

Thanks for the information. I checked all the plugs, they were getting the supply. So I tried jump starting the car again and it didn't. I was disappointed and ready to go to a mechanic just before giving a last try. I turned the key to start and this time I could sense the engine trying to start. So tried another time this time with full throttle... and guess what! The car STARTED!! Engine codes vanished. I could smell a lot of unburned fuel though. Probably because of thousands of cranks I gave it. Now it is starting and running perfectly well.

The question still lies though that why did it not start all the week? I did try it with full throttle many times. I do not know. Hopefully it will run smoothly.

Thanks,
Sanchamp411

if you disconnected the throttle body, you have to reprogram that and idling amongst some other things. Not sure if this is related