I am chasing down a hesitation/miss in my 03 Maxima. It just idles rough almost to the point that you feel like its going to stall. I have replaced the Fuel Filter, the Plugs and Wire Coil Packs. Could this be an injector problem??? The car has 98,000 and regular services. I have ran several tanks of 93 Octane through it with no improvement. I have a Injen intake on it but pretty much the rest under the hood is stock. Any direction or pearls of wisdom would be greatly appreciated.

 

Any check engine lights? How's the condition of the MAF sensor? Is the rough idling/hesistation all the time, when it's cold, or when it's hot (I ask this especially since you're running an injen intake).

 

Maf

 

No check engine lights. And the rough idle is all the time. Even after an hour if driving. Does not run rough when up to speed but idle is rough.

Is there a way to test the MAF sensor. It looks clean and voltmeter shows good conductivity.

 

Any codes? What brand coils? If not oem, then you'll probably have issues. Could be MAF, theres a write up on how to clean it. Could be a misfire.

 

The coils are Hitachi OEM and the plugs are Nissan Platinum.

 

Or you mean NGK Pt.


Any vacuum leaks that you can tell? How's the hosing on that Injen intake, everything where it should be, no leaks?

 

Yeah I'm sure there NGK in Nissan boxes. Bought coils and plugs at nissan stealer ship. No leaks that I can find tightened all the connections, have the poly boots and stainless tubing. The last engine code I had was the high idle code. But I ran through the throttle position relearn procedure and it fixed the code.

 

It could be your Throttle Body. I JUST fixed a similar issue with my Max.

Long story short: Had a nasty nasty misfire... rear coils and all six plugs replaced by a local mechanic - DID NOT FIX the issue

I swapped out the OEM coils from the front, cleaned the Throttle Body, and checked all my harnesses, and did the relearning procedures. - Misfire is history

I can't say for certain that the issue was caused by the aftermarket coils, filthy TB or a harness, all I know is that my car finally runs normal.

If you do a search on Cleaning Trottle Body you will get varying opinions on whether you should or shouldn't do it.

As just one example of many on this forum, I did it and had success with it. Others have done it and ended up doing more harm than good.

The tricky thing about the TB is NOT to move the butterfly.
- Spray the inside of the TB down with cleaner? - Yes
- Wipe everything down immediately after spraying? - Yes
- Move the butterfly? - NO

That's the recommendation I have if you do it, do it carefully. If you do it, in fact, if you clean the MAF, remove the Intake Manifold, and/or clean the TB, you will need/should do the Pedal Position Reset, Throttle Body Closed Position, and Idle Air Volume Relearn procedures.

I would ensure when you start the car that the Service Engine Soon light comes on (to verify it works), see if you have any pending fault codes, clean the MAF, check the TB (I pulled the entire air collector box out to get easy access to teh TB) and go from there. Since you already said you are running OEM coils and plugs.

 

Just cleaned my TB and MAF sensor. Time will tell if this fixes the problem. I'm guessing that will almost 100,000 it may be time to replace the MAF sensor. Does anyone know if Delphi AF10216 Air Flow Sensor is the correct part?

 

Why not go OEM, like we all have.

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