Hi my name is XXXXX XXXXX XXXX Answer.
The description you provided makes it sound like you may be experiencing a misfire. Injectors commonly cause misfires on this model but before you jump to replacing them there are a few things I would like to know about the vehicle.
1, Does the check engine light ever flash while driving?
2, The coils and plugs you replaced, were they genuine nissan parts or after market?
3, has anyone attempted to identify which cylinder may be misfiring? (if not I can help you identify it)
Answer these questions the best you can and I will get back to you as soon as possible.
Thanks for the quick response.
1. Yes, the check engine light flashes when this begins to happen, but doesn't stay on. It stayed on only once and cleared itself when I turned the car off. The code was P0328 and no codes indicating a misfire or any other codes. 2. The coils were aftermarket, Hitachi I believe.3. I didn't attempt to identify a misfiring cylinder, wouldn't it set a misfire trouble code and indicate the cylinder?Also, could you comment on the clicking noise and whether this is something to worry about that might cause problems in the future? Thanks!
The only reason the check engine light flashes is because the computer has detected a misfire. The flashing definition is that damage to the catalytic converters is likely going to occur if vehicle is continued to be driven. So you definitely have a misfire.
The computer won't always detect the misfire. I don't know why but it is common for nissan's computers to not store the misfire data. Seems like they pickup slight misfires but when it comes to a full blown dead miss the computer doesn't pick it up. Kind of screwy huh.
You need to identify the misfire first and to do this you will have check it while the engine is misfiring.
To find the cylinder that is being affected you will need to disconnect one coil connector at a time until you find a coil that doesn't make the engine run worse. (each time you disconnect a coil the engine will start to run worse, this indicates the cylinder is firing properly).
once you identify the cylinder that has the problem, swap the coils with another cylinder and then recheck to see if the misfire followed the coil to the other cylinder. If it did then you have a bad coil. If it didn't move to another cylinder then the spark plug should be removed and inspected. If the spark plug looks okay (no cracks in the ceramic or damage to the electrode) then you likely have a injector that is failing (very common on this model and age) To check the injector you can use a long screwdriver held to your ear so that you can listen to the injector pulsing. It will sound like a clicking noise and you can compare the clicking to the other working injectors. You will likely find that the injector with the misfire isn't clicking in the same way as the other injectors.
If you can confirm this then it is time to replace the affected injector. However due to the age of the vehicle and the likelyness that another injector may fail soon you might want to replace all the injectors or at least do 3 at a time (on the same side of the engine)
Hope this information helps and has earned your ACCEPT, if you have further questions just ask.
Oh I forgot to mention that when the engine is misfiring like you are describing it may make a clicking noise so before diving into that issue the misfire needs to be resolved.
Thanks man. I'm going to do as you suggested and we'll see what happens. If your diagnosis is correct, I will accept ASAP. Also, I'd like to share with you something you might not know yet. I think your web chat interface is the same as mine, so if you press SHIFT+ENTER, you go to the next line, as opposed to sending the message when you only press ENTER. Cheerios!
Hey I will have to try that. This is a new interface that I am still getting used to :-)Well it looks like your tip works. Thanks!
After our conversation, I replaced a failing alternator and the misfire didn't happen for over a week of short-distance driving, but I didn't have the opportunity to test the injectors as you suggested. Then I decided to get the most expensive injector cleaner from Chevron and I'm close to finishing the tank of gas with the cleaner mixed in. The misfire happened 3 times since I filled up, but now it was different in that while it started when I was coming to a stop, it didn't continue when I pulled away - as soon as I went over 1.5K RPM the misfire stopped and didn't happen again until a few days later, where it also stopped after pulling away. So it seems that you're right, one of the injectors is failing and the cleaner provided some relief or perhaps the new alternator prevents it from continuously misfiring. Now I'm hoping I'll have a chance to test it when it happens again. Thanks for the answer.