Nissan Repair: 2001 Nissan Pathfinder misfire, crank angle sensor, variable valve timing

Question
QUESTION: Hello,

I have a '01 Pathfinder, SE, 4x4, 5sp w/ 93,000 miles.

The CE light has been on since I've owned it (3 yrs) w/ P1140: Intake Valve Timing Control Position Sensor (Right Bank). After reading about this code and since the car ran fine w/ good fuel economy, I did not change out the sensor and ignored the light.

Lately however, the CE light has started occasionally flashing for about 30 seconds and the car runs rough for the same amount of time.  Once the light stops flashing, it goes back to running well.  Fuel economy is down though.  I am getting two new codes:

P1320: Ignition Control (IC) Module 4x Reference Circuit Intermittent No Pulses

P0300: Random/Multiple Cylinder Misfire Detected

What action should I take to fix the problem myself (I am reasonably handy as a DIY mechanic)?

Thanks very much!


ANSWER: Jamie,

The crank angle sensor should be replaced and that would correct the ignition control problem.  I would replace the plugs and coils and that should take care of the random multiple misfires.  The timing control position sensor on the right bank and possibly the variable valve timing advance unit might need to be looked at, removed and possibly cleaned or replaced.  The engine is cool and the cams actually advance with RPMs and this is controlled with the variable valve timing solenoid on each head.  If they get plugged they will not advance and the mileage will go to heck...  Get a Haynes or Factory Service Manual and you will have the photographs to look at to aid in the replacement.  Your Pathfinder is great and easy to work on and the parts you need to look at and clean or replace are all easy access.

---------- FOLLOW-UP ----------

QUESTION: Thanks for the response.

It looks like the Crank Angle Sensor can not be purchased separately, but rather as part of the distributor.  The Distributor is a $300+/- part.

Replacing all of the coils will get expensive pretty fast at about $100+/- per cylinder.  Since it is random and not a particular cylinder, is there a chance that the misfires are a resultant of the sensor issues?  

Is there a way to test the coils and narrow it down to a cylinder?

I guess I am asking, what is the conservative approach to solving my 1320 and 0300 errors rather than replacing everything?  Unfortunately, I don't have an extra $1000 dollars laying around.

Thanks again,
Jamie

Answer
Jamie,

First, purchase a Haynes Manual for the specifics on your vehicle and a digital volt/ohm meter.  Follow the instructions in the book on checking the ohm resistance on the coils to make sure all of them are in good working order.  If one is out of range change only that one.  On the distributor it is the same story in checking output for the signal to the computer.  Only replace it if it is defective.  But, the P1320 is pretty specific and that really points to the distributor.  That is only from my experience...  This would also make the random/multiple cylinder misfire.