Problem: fuel, but no spark.

Used this link for 1993-98 Maxima: http://www.autozone.com/servlet/UiBr...3d801f4f97.jsp

Troubleshooting procedures taken: checked (with digital multimeter) both crankshaft position sensors ("pos" for volt reading and "ref" for ohm reading) and the camshaft position sensor for "ohms".

The results:

crankshaft (pos): 12.1 volts (according to above link, it should be 5!)...tried numerous combinations, paid most attention to the #2 (white) and #3 (red) wires per the link site. They say to touch a screwdriver to the sensor "core", which I'm assuming is the magnetic portion that reads the flywheel.

crankshaft (ref): within link specs

camshaft position sensor: within link specs

Also checked: all grounds (3 total...alt, engine wiring harness and main battery ground): 12.39 volts at each.

So...do you think my crankshaft position sensor (POS) is bad???
Would this explain the no-spark condition and should I just go buy a new sensor from Nissan?

Thanks guys.

 

A bad CPS (POS) will cause erratic spark, but there will still be spark.

 

Alright...so assuming it's a fact that there will be erratic spark (while I have none whatsoever), what should I check next? The '97 FSM recommends replacing the CPS (POS) if the reading isn't 5V (as I mentioned, it is at 12.1V on my car). As I mentioned above, I've already checked the grounds, CPS (REF) and the camshaft position sensor.

 

have you tested the coils?

 

Doubt that the coils would all fail at once.


Did you check the ground wires for each coil plug?

 

No...I haven't checked any coil plug ground wires. If one is bad, will all 6 coils not function or ? Thanks for the suggestion...at this point, I'm considering all possibilities.

 

if one is bad just that one will be bad.

 

Keep us updated.


Some things from teh FSM:

1. When the key is in the "on" position, the #3 terminal on each coil harness plug should read .01 - .1V, (these are the different colored wires, not the red or black wires going to the coil)

2. The red wire on each plug should read battery voltage when key is at "on" position. (If there isn't battery voltage here, check the condenser plug.)

3. Black wire on each should be ground..


Make sure the condenser plug is plugged in...