StepZ

Moderators: I originally posted this thread in the General section for 03-09 Zs. I believe it is more suited for this forum.

Hello All! I am new to the forum and am hoping to get some guidance from the powers that be of the Z world.
Vehicle background: My wife's car, driven daily, 2006 Enthusiast, 122k miles, automatic, 4-5 month old battery, 1 month old spark plugs, no leaks or oil burning, well maintained. Threw EVAP small leak code 8 or so months ago, so I cleared it and it never came back. Threw right bank cam sensor code 5-6 months ago, so I replaced it with an Intermotor sensor.
My background: DIYer, worked in automotive machine shop for a couple years, Meineke a couple years, Advance Auto 3-4 years; currently a Mechanical Engineer. I have a fairly wide experience in vehicle repair and diagnostics.

The problem:
About 6 weeks or so ago, my wife told me that the car was getting harder to start. She told me that it would crank, but not start right up; sometimes it would kind of hesitate and then pick itself up, sometimes it would shutter and die off quickly and she would have to restart it. Then, once it fired off, it ran like a top through all power bands. (I searched and searched and searched.. and searched for this problem and everybody has their own story. Plus, some are vague, or not updated with solution, or not the same conditions)
I drove it one night, about 5 miles or so, went into the store for ten minutes and came out to the same condition.. it sputtered and died the first time I cranked it; after that it just cranked and cranked. I opened the glove box, took out the false floor and beat on the pump while cranking, but that did nothing. She told me that she would sometimes pump the gas while cranking and it would eventually start.. so, I tried that, and it did eventually sputter and sputter while cranking until eventually starting. Once it started, again it ran like a top. Since then, she has been driving our spare car.

The diagnosis:
All throughout my diagnosis over the past 3-4 weeks, the car has been at our house, temps have fluctuated from about 70 to 12 degrees, and I have randomly gone out to the car to try starting it; sometimes it starts up perfectly, sometimes it does the same as mentioned above. I notice no connection to temperature, drive time, frequency, or operating temperature.
- Checked codes, none at all.
- Replaced plugs; no change. Old plugs looked normal for being what I think were originals (no fouling, no oil in tubes, no black/rich-look, no ashy/lean-look)
- Cleaned the with the right CRC cleaner; no change.
- Sprayed the throttle body with CRC TB cleaner without removing it; no change.
- Did the ECU/throttle relearn a couple of times; no change.
- Sprayed TB cleaner around intake and vac hoses while running to see if there could be a vac leak, no change.
- Checked battery terminals and they are not loose, and there is no build-up.
- Had my doubts about the cam sensor, so I ordered a Delphi and installed two days ago. Started fine for a day, and then yesterday it did the same sputter and die, with a no-start "crank-crank-crank" condition to follow. I will say that when the car started right up the other day - each time I started the car, I could smell what I thought was a stronger than normal un-burned fuel smell.

I am holding off on spending the $50-$60 on the fuel rail adapter to check the fuel pressure because I am feeling like the car would starve for fuel at some point when driving, and the problem should not be so intermittent if the pump was failing.
Needless to say, thank you for reading my post. I am open to all suggestions but I do not want to throw parts at it or go to the dealer if I don't have to. I will at the very least post a final solution when found so that anybody with this annoying problem can save themselves the frustration, time, and money!
I posted videos below.
Thank you in advance!

**UPDATE: SOLUTION posted in #20 of this thread.. Diagnosed as Fuel Pressure Regulator within the pump assembly. I replaced the fuel pump, all fixed so far!

zakmartin

Can you do a live scan on your absolute throttle position sensor and accelerator pedal position sensor to see if the throttle-by-wire settings are within spec (outlined in the FSM?)

I'm leaning toward fuel issues as a possible source of the problem (though in all fairness, any number of things could cause this issue and not throw a code.) A cheap way to test the fuel itself (given the temperature extremes you've recently been experiencing and the probability of condensation issues in the tank) would be to add a bottle of water displacement additive like HEET. You might want to add some Techron Concentrate Plus over the course of the next two or three fill-ups as well; consider it to be something akin to a car enema.

eZg

iTrader: (5)

try checking all the grounds?

StepZ

I have a little scan tool from Advance that will live scan, however it is not very fast; so when I have used it before and the car starts up fine, it does not give me an accurate reading by the time the car starts. I could plug it in each time I start it to check for TPS reading eventually at a time when it does not start.

Checking the grounds is a good idea. From what I can tell online, there should be four that stand out, correct?

eZg

iTrader: (5)

not sure...I had this same problem and it turned out to be loose battery clamp...but you said you checked them...

good luck.

StepZ

I will check grounds when I get home as well.

I'll try the Heet as well, but this car has been around in these temp swings its whole life with no condensation problem.

And I forgot to mention, the anti-theft light is never on when I try to start it, so it is not the common key issue. But, if the NATS antenna were malfunctioning, would that cause the light to stay on as well?

I normally wait 3-5 seconds before starting to let everything come up to speed too.

Cavemanz33

Sounds like an issue with fuel pump, it might be starting to fail and not send enough fuel. If your fuel pressure is fine (should be within 50psi), then double check your grounds. For my car, the one in the back of the engine was not tightened enough so it didn't turn on the motor. You still get no codes right?

StepZ

I checked all grounds, and everything is tight and clean. Still no CEL, but I forgot that I let a co-worker borrow my scan tool, so I couldn't "officially" check codes.

I started the car a whole bunch of times after I got home yesterday and I recorded video each time to see if I could catch it... Started up great every time of course! So now I am just going to drive the car and take video each time I start it, hoping I can catch it.

One thing I have taken note to: I am using a key without the fob, so I have not been arming the alarm system. Not sure if there is a link, but I will keep using the same key and not arming the alarm as an experiment.. I say that, now watch the stupid thing leave me stranded.

eZg

iTrader: (5)

better you than your wife.......

StepZ

eZg, I could not agree more.

I have been taking video every time I start the car (which is 2-5 times a day) so that I could eventually catch the symptoms. There was one time two nights ago that the car did the same as the "Third Start" below; which was a start, then abrupt shutdown, and then I could start no problem on the second attempt directly after shutdown (however, I was on the phone for that one and could not video). This morning, she finally showed her colors... All three start-ups are on youtube links below and show what we sometimes go through when trying to start the car. Each video is very short because, even when the car doesn't start the first or second time, it will eventually start right up within 30 seconds.

First Start: - The car does a hiccup, but then starts right up

Second Start: - The car cranks and cranks, then starts right up

Third Start: - The car starts up, shuts down, then it starts right up

I drove it to work again today so I can run the gas out of it. I will put fuel injector cleaner in the tank today, with some new premium fuel.

StepZ

So I put techron fuel system cleaner in the car yesterday and drove it today. I drove back towards home for about 50 minutes, parked, came out and tried to start the car about 30 minutes later.. The car did a low idle/stumble up and down for about 15 seconds until it shut itself off. So, then I pulled out my phone and started recording.. The video attached, , depicts what I mentioned in my original post, which is what got me really start to diagnose this thing.

About 1:30 or so into the video, I started to pump the gas, which eventually led to the car starting. I am confident it never would have started without it.

Thank you again for any help you can give me!!

https://youtu.be/nkOxn9WYfCY

zakmartin

Without being able to hook your car up to my computer and do a diagnostic while the intermittent problem is non-intermittent, you're going to need to start on page 83 of the Engine Control portion of the FSM and run through the troubleshooting list to get this thing figured out. If you think you can shade tree this one without the right diagnostic equipment, you may be out of luck. A problem like the one you're experiencing can go in a bunch of directions, but after watching the videos, I'm fairly certain that it isn't something as simple as a bad fuel issue.

Just remember: the 350Z does NOT like aftermarket sensors. Also, your IPDM can be a source of intermittent problems. See page 30 of the Power Supply portion of the FSM for your model year.

Edit:

I re-read your first post and saw you reported that the car "Threw EVAP small leak code" that you cleared but never checked (assumedly.) Also, you said, "I could smell what I thought was a stronger than normal un-burned fuel smell."

This would point toward an issue with your evaporative purge solenoid, which could cause the symptoms you're experiencing. You'd smell the fuel since the canister and control valve are located near the cabin pressure equalization vent. A bi-directional tool will allow you to actuate the solenoid to see if it's functioning properly under pressure, as outlined starting on Page 32 of the FSM's Engine Control module. Either way, do a sniff test in the evap canister area, located in the right rear of the car to determine if you can smell gasoline. If you can, then inspect that part of your system.

StepZ

Thanks for your input zakmartin! I have been giving this some thought and I briefly ran through the FSM. Once the snow here clears up some (day or two), I will sniff around the car.

Now that you mention it, and I started looking into the EVAP system more, I do recall having troubles at the pump from time to time. With no rhyme or reason, the gas pump would should itself off while fueling. This has been an ongoing thing for years, and I do not necessarily recall anything really recent. However, sometimes the pump would shut itself off so many times while fueling that I/she would only put $5-$10 in the tank and move on. She always just chalked it up as a fluke thing because it didn't happen all the time, thinking the gas pump was to blame.

I will certainly dive deeper into this today as a possible relation to the ultimate issue.

zakmartin

That would be the vapor vent tube and would not likely be related to the issue. Nissan recently did a warranty extension for this problem, which I covered in THIS THREAD.

It sucks that your weather's so bad. It's a balmy 50 degrees in here in Seattle and we've missed all the deep freeze misery you've been having back East. Report back when you've had a chance to delve deeper into your diagnostic.

StepZ

So I sniffed around under the rear of the car and could not detect anything of concern. I also checked the purge solenoid and that's working like it should.
At this point, we are probably just going to take the car to the dealer for a proper diagnosis. We will get the fuel tank warranty done then as well.
And I agree about the weather here. We have gotten quite a bit more snow and temp drops than usual, but this area of va is known for crazy temp swings. Shorts one day, and snow pants the next.

StepZ

Update:
We took the car to a local dealer and they could not get the car to replicate the problem at first; they recommended a fuel system cleaning and new plugs - to which I responded I already tried both. Then, the service writer took the car to lunch one day and shut it down (which I told him to make sure they go through a drive-thru and make sure they don't shut down until they get back to the shop), and the car nearly left him stranded. He cranked and cranked multiple times over 8-10 minutes and eventually got the thing to start. He told his techs of the issue and they could not get the thing to replicate the problem once again with the computer hooked up.. They said that they were "leaning towards the fuel pump"..
Needless to say, I picked it up from the dealer free of charge (which was nice considering they did a oil change and the fuel tank vent tube warranty repair for us while it was there). I took the car to another local dealer and left the same instructions for them. The next day, they got it to replicate the problem and they could not figure out the cause so the called the Nissan Engineers at home base; which suggested a throttle body cleaning and throttle re-learn.. I was hesitant, but if that was their only suggestion from the heads at Nissan, I had to concede. The result: "The car is better, but still not 100% fixed", whatever that means.. They got the car to replicate the problem again and tested the fuel pressure when trying to restart after sitting for ten minutes following a twenty minute drive.. and they found that the fuel pressure was not holding.

Their current diagnosis: Fuel pressure regulator intermittent failure. Not sure how this happens only when being warmed up and then letting cool for ten minutes; but again, I have to concede as they are the pros. So, I ordered a fuel pump over the weekend and am picking the car up today. Pump should be here today or tomorrow and I will install and report the results. This was my diagnosis from the get-go, and I am hoping this solves the problem. Once fixed, we are trading in or selling the car.

eZg

iTrader: (5)

Thanks for updating.......hate you are getting rid of it....but understandable.

StepZ

To its defense, I drive a Nissan Sentra as my daily and have had nothing but good things to say about the car. Her car has been dependable until this freak problem as well, so we are not selling due to this issue.. she has been in the market for a Wrangler for a while, so now is the time. If the Z was manual, I would probably keep it for myself as a track car.

eZg

iTrader: (5)

Cool.....I have a JK with almost 60K miles and not one problem. It's a 2014. Heard about some updates on new 2018s but have not seen them.

One thing I LOVE is the oil filter is on the top side of the engine. Easiest oil changes I have ever done.

Good luck Man!

StepZ

eZg, we have been searching for the perfect JK for awhile, but now we at least have a running trade-in!

**UPDATE**

The dealer called yesterday and said that the driver side fuel damper was bad as well and they had to take it off to test it. So, I had them replace that just in case that was the fix (plus they only charge $125 and after shipping, the part would have cost me about $100; so why not, if they say it is failing?). Picked up the car last night, got it home and parked it for 10 minutes or so and went back out to test it.. same symptoms as the most recent video I posted above. Went back inside with my tail between my legs.. then, the pump showed up in the mail just in time..

SOLUTION:
I installed an Airtex fuel pump and the car started right up after cycling the key a couple times. Drove it for a test drive, came home, let it sit ten minutes or so.. started right up. Went back out another ten minutes later.. started right up. My wife is back to driving it today, so I will post if the beast rears its head again. SOOO relieved.. for now..

NOTES:
The dealer claimed it was a fuel pressure regulator problem (which is in the pump assembly), not necessarily the pump it self.
For anybody who is going to do the fuel pump themselves:

• This was a very simple installation
• Be careful when pulling the fuel line apart; it will have pressure even after being shut down for awhile
• Don't lose the plastic clip holding the fuel line on because you may need it for the new pump
• Take note of the fuel gauge reading before and after install
• When you slide the new pump in, make sure it is in the correct rotation/orientation because there is a PITA little hose that you have to hook up before putting the pump in; and if that hose gets bunched up in the wrong direction, it could hold the float down or up and give a false reading on the gauge (yep, learned that from experience.. had to technically do the job twice)
• The Airtex pump is quite a bit louder than the stock one (maybe the stock one was getting weak), but at least you'll know if that thing isn't working

Good luck to all, and I hope my frustration can provide someone else some guidance!