Does anyone happen to know why the car doesn't start? It was working fine before.

Here is what happens, when I try to turn on the car:
-1st time it starts then it idles hard and it shuts off after a few seconds
-2nd time it starts then dies right away (It seems that fuel gets cut off)
-3rd time it just cranks and it won't start.

( I replaced the fuel pump and it's the same problem )
It does prime.
Strange thing is I was just replacing front O2 oxygen sensors and it started doing that IT WAS RUNNING FINE BEFORE . So I restored the old O2 oxygen sensors and it's the same problem.

Could anyone suggest anything please?

 

Do you have an aftermarket alarm?

Have you tried using a different key?

Do you have an auto starter?

Sounds like an alarm or key issue, is the check engine light on?

Maybe try disconnecting the battery for a few hours and try again.

 

First question, why did you replace the o2 sensors? If you replaced because of a code, please list the code.
I am willing to bet they were lean codes, have you checked for vacuum leaks or disconnected maf sensor?

 

Have you tried using a different key?
I only have 1 key and a remote

Do you have an auto starter?
auto starter? never heard of that, I don't think so. I bought the car and it did have previous owners

Sounds like an alarm or key issue, is the check engine light on?
And Yes the check engine light is on

Maybe try disconnecting the battery for a few hours and try again.
I will try that and see what results I get.

THANK You soo much for replying!!

 

I was replacing the O2 Sensors from a diagnostic based on bad A/F ratios for a P0300 (Cylinder Misfire Detected Random Cylinders)
It was diagnosed by the pros over at Corner 3 Garage

Also I can't find any vacuum leaks, I've disconnected the MAF sensor and it's the same thing with our with out it.

Any other suggestions please let me know! I will also check the fuses
(This is strange, perhaps I moved a cable while clipping the new sensors?)
It was working fine before and had not problem starting up.

 

If a CEL shows up after d/c the battery, be sure to find out what it is. It could be a NATS issue if the chip in the key is not matched to the vehicle.

 

With a random misfire and these startup issues I would recommend checking fuel pressure next. Fuel pump may be weak. A large vacuum leak can cause the same condition as well.
There were no other codes?

 

I had a conversation with a staff member from the Nissan dealer and he said if it was the NATS, it would only crank but not start at all. And I'm able to start the car the first time but it idles rough then it shuts right off.

 

Unfortunately I don't have the tools to check the fuel pressure for this VQ35DE, and there is no tutorials on how to do so with out a proper $500 dollar kit from nissan
I also replaced the fuel pump and no avail, same results.
-No other codes just the P0300. At this point I might have to figure out how to get the car towed to the Nissan dealer so I can have them inspected.


Thanks again for taking the time guys to reply to my post I'm really grateful honestly, for this community.

 

How are your catalytic converters? If they have collapsed or have a blockage it might cause these problems, a clogged air filter could also but the clogged catalytic converter is a more likely candidate...

If or when you figure it out do us a favor and let us know what it ends up being...

Good luck

 

Thanks! but it's running straight pipes~

 

Loose ground cable LOL

http://mechanics.stackexchange.com/q...nks-wont-start

however I'm still getting P0300, car still feels sluggish and can't figure it out why =\

 

Pull and check each of the plugs. Those will give you an indication if the problem is mechanical. Check each of the coil packs with scope or a probe to see if they're firing. Check the injectors with a probe to see if they're all working properly. Check for proper vacuum.

If you can't do this VERY basic work, then take the car to a garage who can. If you're getting a constant misfire, it's likely going to be coils, injectors or vacuum leaks but there are a bunch of other things that can be causing it as well. Knowing how many miles are on your car, a list of engine modifications, maintenance history and any other contributing factors would be enormously useful information to share when you're asking for assistance on the maintenance forums.

 

Ground wire was loose but I'm left with P0300
Car: 150k / 2003 / 350z Manual / Enthusiast / PROJECT HARD-LADY
[ Stock / DC intake / Straight pipes ]
Engine: VQ35DE
OBD2: P0300
(salvage, back right bumper dented frame)


(11/11/2016)
My Cousin is a certified mechanic and took over the repair!

-Car idle rough and After moving the front cable harness the car would shut off
**+Ground wire was loose** and would cause the car Not to start. NOW CAR TURNS ON FINE

+He also found a minor leak on the manifold and order a gasket to fix it (:
+Tested compression and got @ 120 cold then at warm @ 150 but awhile ago I had 190 psi from all 6 cylinders on 6 cranks.

However Car is still sluggish with the P0300 / I can smell unburned fuel in cabin / When I'm out of the car my clothes are penetrated with the unburned fuel smell
Now I'm left with the P0300 code
- I drove it around and car works but I do notice it sluggish. It doesn't accelerate beyond 5-6k RPM's on full throttle on 3rd/4th


VIDEO HERE Is spark normal^ ?


-New Synthetic oil and filter
-New Exedy clutch and ACT flywheel
-New Battery
-New Camshaft sensor
-New Crank position sensor
-New NGK Spark Plugs (covered in gas but cleaned)
-New resonated straight pipes
-Recent Premium Gas tank
-Checked injectors @ 17 Ohms
-New fuel pump motor
-New Fuel pressure dampers
-Sprayed MAF cleaner
-New aftermarket coils [10mm] size difference (perfomance the same with stock) however I did have 1 bad stock coil
-New intake manifold gasket
-Checked Compression on 1st cylinders @ 150 psi (before when the car wasn't running for a month cold it was at 120) and before that I had 190 psi months ago.
-New OEM Throttle body
^RECENT

TO DO:
-Test fuel pressure?
-Seal a small exhaust leak in the back
-MAF sensor replacement test?
-Cheap spark plugs replacement?
-Order the entire fuel pump system ?
-Order Other Performance coils since this aftermarket ones are a bit shorter than stock. Perhaps order performance coils? they are $150 on amazon (all 6)
-Buy grounding kit

(And Finally; I Really want to fix this myself to learn how these cars work, I love this car... but perhaps I may have to take it to the shop like you said

 

Thank you for telling us what happened, had this same exact issue for a month now, car sometimes would not start no matter what I did, thought it was water in the fuel.

Fixed the broken ground on the front part of the engine harness and poof, good as new.

 

I'm glad that fixed it for you, Hopefully this thread will be indexed when people search for similar symptoms.

( I finally got rid of the car and Bought another ONE LOL 2nd Z ) The previous problem I had with the P0300 was the RPM's would not go beyond a limit and was due to clogged exhaust pipes and was triggering the p0300 thus the engines fumes were coming back into the engine since they couldn't release through the clogged exhaust system from destroyed Catalytic converters and would trigger that code.

LONG STORY SHORT:
1. P0300 could be caused by CLOGGED EXHAUST SYSTEM from debris of the Catalytic Converters.
2. 5-6K RPMS will not go higher due to CLOGGED AIR EXHAUST SYSTEM.