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Discussion Starter #1
Hello again, 'nother problem:
Driving home this afternoon, Armada started running rough shaking and got p0308. Started smoking pretty bad out of the tailpipe and died on the side of the road. Got under the hood and checked connections etc. Managed to baby it home and did some diags. Only code that ever came up at all was p0308 and not returned. After it gets a little warm, the idle goes up to about 1500 and then back to normal, does this at regular intervals. Pulsating actually. like you are doing it with your foot revving the engine. Switched out the coil with a known good one, no change. Double checked my uprev tune to make sure it was on the right tune, it was. No idea what to look at next. I'll have to have it towed to the mechanic Tuesday if we can't think of anything.
No milkshake in either the coolant reservoir or oil filler tube. If I rev it there is a lot of smoke, possibly unburnt fuel from bad injector? These injectors are OEM Nissan rebuilds so could be.
Let me know if anyone has any ideas, I would greatly appreciate it, many thanks in advance!
 

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It is possible the fuel injector for cylinder 8 is getting stuck open. Disconnect the pigtail from fuel injector/cylinder 8. With a multi-meter, set it to ohms and check the resistance on that injector. It should read between 11.5-12.5 ohms.
 

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Discussion Starter #4
I will try both of those tomorrow. It would't be anything majorly mechanical like burnt piston, bad valve etc. Also, would one bad injector cause such a large range of hunting idle?
Anyway thanks for the input guys, guess I will buy a multimeter!
 

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I will try both of those tomorrow. It would't be anything majorly mechanical like burnt piston, bad valve etc. Also, would one bad injector cause such a large range of hunting idle?
Anyway thanks for the input guys, guess I will buy a multimeter!
Compression would be the next thing to check if the injector(s) are within spec. But usually with a bad piston(s) or piston ring(s), you would've noticed issues prior to what's going on now. Either poor or almost no acceleration, a huge amount of oil consumption and piston slap/knock noise are typical signs. With bad valves or valve seals, the most obvious is blue smoke coming out the tailpipe along with poor engine performance too.
 

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Discussion Starter #6
I've noticed nothing out of the ordinary prior to this afternoon. Although, once it started running rough today, it was hard to accelerate, but then would clear itself up and accelerate normally. If you watch the vids I posted last week one can see how well it was running. No oil consumption and no smoke, hope I dodged a bullet! If it is something major, I will have the headers and catted b pipes removed and sell them at a great price!
 

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If you pull that plug for inspection, also move it to another cylinder. If it's the plug, the DTC should follow it to that cylinder.

So the past few weeks you have been flipping around between octanes and UpRev tunes and doing 0-60 WOT runs... wonder if that has contributed to this condition.

If none of the above suggestions pan out, I would be tempted to put the stock tune back on just to see how it reacts to that. Might also be worth contacting Joe and see if further datalogging might provide any additional information that he could analyze.

Hope the solution is pain free!

Also while you've got the hood up, check your PCV valves...

A bad PCV valve or related component can produce a number of symptoms. For example, if the valve clogs, or gets stuck in the closed position, you'll notice one of these symptoms.

Symptoms of a Bad PVC
  • Increase in internal engine pressure
  • Failure of one or more oil seals or gaskets
  • Engine oil leaks
  • Moisture and sludge buildup inside the engine
  • Engine surges and possibly black smoke
If the PCV valve gets stuck open, or a system hose gets disconnected or ruptured—producing a vacuum leak—you'll notice one or more of these symptoms.

Symptoms of a Stuck PCV
  • Engine misfires at idle
  • Lean air-fuel mixture
  • Presence of engine oil in PCV valve or hose
  • Increased oil consumption
  • Hard engine start
  • Rough engine idle
In addition, a PCV valve stuck open can trigger the "check engine" light due to increased air flow. And a diagnostic computer may erroneously blame this light on a mass air flow sensor or oxygen sensor instead, making it harder for you to detect the real source of the problem.
 

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Discussion Starter #8
I did some 87 runs, used the tank, filled up with 91 did some runs, and now back to 87, I had thought that maybe I left it on 91 tune running 87 which I read could be bad, but it was/is on 87 now. I think I will check the above mentioned, then put the stock tune back in and see what happens. I won't be driving it much until I get this sorted. Not even driving it to the mechanic. I will have it towed. It's weird as driving to work this morning everything was fine. Nothing seemed amiss. So, I have to believe it is something simple like a bad injector.

Also while you've got the hood up, check your PCV valves...

A bad PCV valve or related component can produce a number of symptoms. For example, if the valve clogs, or gets stuck in the closed position, you'll notice one of these symptoms.

Symptoms of a Bad PVC
  • Increase in internal engine pressure
  • Failure of one or more oil seals or gaskets
  • Engine oil leaks
  • Moisture and sludge buildup inside the engine
  • Engine surges and possibly black smoke
If the PCV valve gets stuck open, or a system hose gets disconnected or ruptured—producing a vacuum leak—you'll notice one or more of these symptoms.

Symptoms of a Stuck PCV
  • Engine misfires at idle
  • Lean air-fuel mixture
  • Presence of engine oil in PCV valve or hose
  • Increased oil consumption
  • Hard engine start
  • Rough engine idle
In addition, a PCV valve stuck open can trigger the "check engine" light due to increased air flow. And a diagnostic computer may erroneously blame this light on a mass air flow sensor or oxygen sensor instead, making it harder for you to detect the real source of the problem.
It has all new Nissan valve covers and new pcv valves that came with the set. But I DO know one of those hoses is suspect.
 

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I had thought that maybe I left it on 91 tune running 87 which I read could be bad, but it was/is on 87 now.
Meh, it ain't that bad. I had put the SuperChips 91 tune on when running 91 octane probably 5 years ago. At some point (probably 4 years ago) I went back to 87 octane and inadvertently left the 91 tune on until just a few months ago when I switched over to UpRev and had to remove my SuperChips tune... that's when I saw it was still on 91 tune. I think the only real difference between UpRev's 87 and 91 tune is the 2* timing advance. I know there are folks who intentionally run a 91 tune with 87 octane just for the timing advance.

Hopefully you just have a fouled plug.
 

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Discussion Starter #10
Update: This afternoon I did some more digging. I used cylinder #4 as a control. Pulled the plug, it looked used, more so than I thought it would for less then 1k miles. Also checked the pigtail for that injector, it read 12.5 ohms steady. Pulled plug on #8 and it reeked of gas. But actually looked clean. Tested the pigtail, and it IS hard to get to with probes, but it jumped all over the place all the way to 147.5 and finally settled on 13.5. So, is this indicative of the injector being open and not in spec? Shall I order a new one?
I started it up again, and it idles sweet on high idle, for about 15-20 seconds, then drops down and starts missing and there is no mistaking a strong smell of gas in the exhaust. Let me know what you guys think!
As always, many thanks for the help...
 

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I hate throwing parts at a problem but in this case you suspected a fuel injector and confirmed it - as far as I am concerned. If you hadn't confirmed it I wouldn't have bought an injector based on an internet guess. But at this point, I'd get a new injector and try it out. One OEM injector is way cheaper than a tow, min 1 hour diag fee and mechanic fee to replace that injector.
 

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Discussion Starter #12
I hate throwing parts at a problem but in this case you suspected a fuel injector and confirmed it - as far as I am concerned. If you hadn't confirmed it I wouldn't have bought an injector based on an internet guess. But at this point, I'd get a new injector and try it out. One OEM injector is way cheaper than a tow, min 1 hour diag fee and mechanic fee to replace that injector.
So you would say it is not in spec? And the wettish(?) and heavy gasoline smell would confirm this? If so I will order one tonight! THANKS!
 

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Yes - that is what I would say. Of course, you don't know me and I don't know you. I could be a 12 year old for all you know.

But if it was my car I'd be buying and replacing that injector. I think primov8 was exactly right - that injector is stuck open or partially open and is dumping too much gas into the cylinder, flooding it, causing a bad misfire, causing the spark plug to be wet with gas etc. If it stays like that you can ruin your cat because the unburnt fuel can get in the cat where it will burn up the magic stuff in there.

I try to not be too definitive here because most people are looking for a quick cheap fix and will then start shooting the parts cannon at a problem hoping it fixes it. But testing the resistance of the injector is like doing the math, you proved the theory. You can look up other injector testing methods but this is enough for me.

A good friend of mine is a great mechanic and he always reminds me that any monkey can change a part, knowing which part to change is the hard part.
 

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RockAuto has a selection of injectors from various Mfr's from a low of $25 up to Nissan's brand of $126. I know some parts are suggested to always stick with the Nissan brand. Don't know if this is one of them or not.
Maybe Primo or Staple can weigh in on that.

The below RockAuto link is for 2005-2015, but plug in your particular year to validate. Also worth noting is this:

Should you replace all injectors at once?
If an injector is faulty on a vehicle with high mileage chances are the remaining injectors are in a similar condition, or will be in the near future. Replacing your injectors as a set ensures each cylinder is receiving the same amount of fuel leading to better performance and improved fuel economy. Since the time required to replace a single injector is about the same as replacing all the injectors it is recommended to replace them as a set.

 

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I'm with staplebox and don't like wasting time and money throwing parts on trying to fix a problem without diagnosing it correctly. If you tested the resistance on that injector multiple times with the same results, then yes, that is definitely a malfunctioning injector. But why stop on that single injector. It wouldn't hurt to check all (8) injectors to rule out any possible weak or malfunctioning injectors. Also, keep in mind when the fuel rail is removed to access the injectors, any other injectors not needing replacement will need new upper O-rings or else you'll have fuel leaks galore.
 

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Discussion Starter #16
All 8 injectors were replaced a few weeks ago which solved my P0300 code. It hasn't returned in nearly a month. The injectors were rebuilt Nissan OEM from a US company I saw on Amazon. However, I will check the ohms on all of them and make sure they are all in spec. I guess one could have gotten past quality control. The one I just bought is a new Bosch, not rebuilt. Hope this solves the problem. If not, then I WILL let a shop take care of it.
Oh hell primov8 I just finished reading your post. So, I need to get new o rings for bank 2?
 

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Since these injectors were recently installed, don't worry about the O-rings.
 

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Discussion Starter #19
Well...some good some bad. When I removed the fuel rail, injector 8 stayed in the hole. So I am thinking it came loose some how. I ohm'd it and it came out to 12.5, but I installed the new one anyway. The bad news is that it seems to be burning oil pretty bad. This video is before it was warmed up. After I let it warm up a little it was not so bad. Went for a test drive smoking all the way. Not bad, but not good either. The second video is obviously from underneath. Something just doesn't sound quite right. What ya think? Is a valve job pretty expensive on these? I will certainly do it if thats what it is, but...well...


 

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The WA60s are notorious with the baffles inside the valve covers clogging up, yielding a white, smokey exhaust as the mileage builds up. My previous 04 did it, even with 3K miles routine oil/15K routine PCV changes. I don’t remember exactly when the exhaust started smoking more than usual but when I installed new valve covers around 130-140K miles, the smoke show was gone.
If the engine is burning oil, a very obvious blue-like smoke is what you’ll see from the exhaust.
 
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