Nissan Repair: nissan quest, mass airflow sensors, mass airflow sensor

Question
QUESTION: 2001 nissan quest runs fine when cold after it warms up it starts running rough and after about ten minutes it will die and wont restart until it cools off.no codes when i checked injector pulse it barely lighted the noid light.i tried a different computer same problem

ANSWER: Mike,

I would check the oil pressure sensor to see if it shows power after it is at operating temperature.  Also, check the fuel pump relay.  If you ohm out the injectors you might find that some are below specification.

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QUESTION: is the oil pressure sensor tied into the wiring somehow to stop the engine from running ? the fuel pump is running when key is on and i'm cranking it over. can a bad injector cause a no injector pulse situation?

ANSWER: Mike,

The oil pressure sends a reference signal to the ECM that keeps the fuel pump relay grounded.  If the sensor is just barely plugged you can get a condition when the car will die.  It is pretty easy to check and see if the oil pressure sending unit is working with a test light or a volt ohm meter.  Also, this will throw you, the mass airflow sensor is a known problem with the Quest.  I do not know if it something to do with  restricted space under the hood.  But, Quests tend to cook mass airflow sensors after this length of time.  Around seven years or so and they go out.

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QUESTION: Van, i got a code 340 now camshaft position sensor.Can it be replced or does the whole distributer have to be changed and do you think this is causing it to run bad when hot and run fine when its cold

Answer
Mike,

If you disassemble the distributor by removing the cap, rotor, rotor post and cover you can see the optical shutter wheel.  If there is any oil on the disc or the optics then you need a distributor replacement.  rockauto.com is a cheap source and their on-line catalog is easy to use.  courtesyparts.com would be more depending on if you purchase new or rebuilt.  rockauto.com price for a distrbutor and cap and rotor is $199.79 for their Richport unit.  The Cardone unit is $222.79