1991 Maxima Dropping Cylinder

Gymbo · May 19th, 2008, 04:12 PM

I have a 1991 Nissan Makima SE with an automatic transmission. It has 215,000 miles and was purchased new by my parents. After starting it up last Wednesday evening it ran rough. After a stop and restart it ran fine. I started it the next evening after work and it has ran rough ever since.

I have played around and by unplugging one spark plug wire at a time, I have determined that it is the driver's-side front cylinder, which I think is #6. When I unplug that wire, there in no change in how it runs, when I remove any other plug wire the car runs worse. I changed the spark plug and plug wire, which didn't fix it, but at least eliminated them as possibilities. There is spark coming out of the wire end when the engine is running. The rotor and cap are new as of last fall and look fine.

My next candidates are:
Injector
O2 Sensor
Mass Airflow Sensor

The car still revs and runs pretty well, just rough.

I have run a can of Seafoam through it seeing if that would clear out the fuel system.

The car also has an exhaust leak I can hear in the back of the engine, I haven't torn it down to figure out where yet, I am thinking it's probably a manifold stud?

Any thoughts on what my problem is and/or what I should check next?

Thanks in advance.

internetautomart · May 19th, 2008, 05:27 PM

it's probably an injector.
just buy a new one and be done with it.
Internet Auto Supply <- good source for injector

Gymbo · May 19th, 2008, 06:27 PM

Thanks for your response. That was my guess, based upon reading other threads on the forum.

How difficult is swapping out an injector?

Thanks again.

internetautomart · May 20th, 2008, 08:28 PM

it's tough but not impossible. you could have to swap a motor..