Narrowing Down 1998 Nissan Altima Start Problem

Altima cranks but won’t start

Fuel Pressure is good

Spark is good

Battery is weak, but turns the engine over sufficiently

Codes are crankshaft position sensor and knock sensor. Knock sensor code was present before car stopped running.

Timing chain is turning camshaft.

Buy a battery charger and a crankshaft position sensor.
Replace crankshaft position sensor, and recharge battery.
See if engine fires up.

Without a working crankshaft position sensor, the car won’t know when to fire the spark plugs, since the ecu doesn’t know that the engine is turning.


Yep I think the car is telling you what it needs right there…if you have a bad crank sensor it will fire your plugs late or in the wrong order or time…thus causing a no start. Start at the sensor the car is talking to you…easy to replace and rather cheap…you can even get one from a salvage yard as they dont go bad very often

Before you actually install the CkPS at least inspect the wiring & check at the harness for voltage first. There’s nothing like a replacing a part when it wasn’t bad. You can also check the CkPS with an ohm meter - I don’t know the specs off the top of my head but Autozone’s online repair info may have it.