I don't want to sound dumb but I really need any help I can get right now. My Z will not start some sometimes, and sometimes it will. My car cranks but the engine will not start. , it can take me anywhere from 1 try to 10 tries to get my car started. I've bought a new battery, and had 3 of my o2 sensors replaced after this started happening. It's getting worse now. My alternator and starter have been checked as well and they are fine. My check engine light is not on.

 

camshaft position sensors, there are 2 of them

classic signs in my opinion

 

It’s not possible to accurately diagnose the problem and provide a solution by just reading your post. What you will receive here are various guesses, which in fact might help you narrow the discovery process.

I’m going to offer the first guess…

I am going to guess the problem is related to your car’s fuel delivery. I’m making this my guess because you state the problem is intermittent and it is getting worse. Fuel starvation matches the description you provide (“My alternator and starter have been checked as well and they are fine. My check engine light is not on.”).

 

I question if the problem is camshaft position sensors.

• He would be able to start the car every time he tried, but with some difficulty.
• He would have the SES light on his dash
• He would get a code.

 

dunno, a local guy to me, his never threw codes, would sometimes start and others times it wouldn't. he swapped them out and never looked back.

we gave him 2 places to start, to me it looks like he throws parts at it instead of taking it in for a diagnosis.

 

I agree that throwing random part-replacement at a problem is foolish. MichaelaZ says he isn’t getting any codes, but he did replace the O2 sensors for some reason he doesn’t state in his post.

Also, it would be very unusual for a faulty camshaft sensor not to throw a code.

I’m still guessing it’s a fuel problem. My second guess it’s an electrical problem aggravated by moisture. Either problem might not throw a code.

 

Maybe the new battery is not performing the way it should? When I had intermittent starting issues (especially when warm) it was my battery

 

I doubt that is the problem because he says: "My car cranks but the engine will not start." His engine is turning over, but it will not start. His problem has nothing to do with the battery..

 

Spike, I agree with you 99% of the time, 100% of the time when it comes to audio but this is the 1% of the time I respectfully disagree with you. When I had my battery issue, the car would crank and crank and crank but not turn over. This happened mainly when the car was warm and almost 100% of the time, when the car sat, say overnight , it would have enough voltage to start the car.

 

When you say "...the car would crank and crank and crank but not turn over"... Was the starter operating?

If "the car would crank and crank and crank but not turn over," it's probably a starter failure.

 

Nope. Starter was fine, it was the battery. After I changed the battery car went back to operating normal with cold, warm or hot starts. Never had the issue again and the original starter is still in the car.

 

when you start the car does the red light on the dash stay on? my wifes z had a key go bad and the body control module wouldn't recognize the key. thus not allowing the car to start.

 

having the same problem thought maybe bad fuel at gas station but tried diff fuel stations it's still intermittent. it did this months ago and stopped for about 6 months. now its happening again i have no clue. 05 350z. soon as i find problem i will post.

 

mine has done this twice to me since May of 2015.