← Almera Nissan Almera repair manuals →
Autopapyrus · Nissan Almera 1.8 QG18DE (2005)
https://autopapyrus.com/guides/nissan/almera/diagnosing-a-no-start-condition/
Compiled automatically from service literature and owner experience. Specs are for the typical configuration — check them against your exact car before you start.

Nissan Almera 1.8 QG18DE (2005): Diagnosing a No-Start Condition

When the starter cranks the engine but it won't start, the problem lies in one of three systems: spark, fuel delivery or compression. On the Nissan Almera N16 with the QG18DE engine, typical causes are a failed crankshaft position sensor, low fuel pressure, flooded spark plugs or a fault in the NATS immobilizer.

Difficulty: Medium Time: 1-3 hours (depending on the fault found) Steps: 11 Tools: multimeter, fuel pressure gauge, 10-13 mm wrench set, carburetor cleaner spray (for the fuel injection test), OBD scanner (recommended), inspection pit or lift

Part

  • 🔩 crankshaft position sensor (23731-4M500 or 23731-4M50B), camshaft position sensor (similar part number; the QG18DE uses identical sensors), spark plugs (NGK BCPR5ES-11 or equivalent), fuel filter, fuel pump (depending on diagnosis)
There's a full repair manual for this car Every system, wiring diagrams and torque specs — not just this job. Haynes and 3 more. See manuals →

Step by step

11 steps
  1. Check the immobilizer indicator on the instrument panel. When you turn the ignition on, the light should go out after 1-2 seconds. If it keeps flashing, the immobilizer doesn't recognize the key. A common cause on the N16 is a loose immobilizer antenna around the ignition lock, or a key whose chip has been lost. Remove the steering column trim, check the antenna connector and clean the contacts.
  2. Remove one spark plug and inspect the electrode. If the plug is wet with gasoline, fuel is being delivered and the problem is spark or compression. If the plug is dry, no fuel is reaching the cylinders.
  3. Check for spark. Remove a spark plug and fit it into the spark plug wire (or the ignition coil, if it's an individual-coil design). Rest the plug's threads against an engine ground point and have a helper crank the engine with the starter. You should see a strong blue spark. No spark means a problem in the ignition system or the timing sensors.
  4. Connect an OBD scanner and read the trouble codes. Codes P0335 (crankshaft position sensor) or P0340 (camshaft position sensor) point to a failed timing sensor. Without their signal, the ECU will not command fuel injection or spark.
  5. Check the crankshaft position sensor. On the QG18DE it is on the rear wall of the cylinder block, about 15 cm above the starter, and is reached from under the car. Disconnect the sensor connector (release the locking tab) and use a multimeter to measure the resistance between the sensor's two terminals. It should be 480-580 ohms at room temperature. A reading outside this range, or an open circuit, means the sensor is faulty. To replace it, remove the 10 mm or 13 mm mounting bolt and pull the sensor out of its bore.
  6. Check the fuel pressure. Connect the gauge to the test port on the fuel rail (if equipped), or install a T-fitting in the supply line ahead of the rail. Turn the ignition on and the pump should build pressure. On the QG18DE, normal pressure at idle is about 2.8-3.0 bar (280-300 kPa), rising to 4-5 bar under load. Pressure below 2 bar points to a weak pump, a clogged filter or a faulty pressure regulator.
  7. Listen for the fuel pump. When you turn the ignition on, you should hear the pump hum in the tank, from the area of the rear seat, for 2-3 seconds. If you don't hear it, check the fuel pump relay and fuse in the fuse/relay box under the hood, and test the wiring to the tank.
  8. Do a fuel injection test. Remove the air intake duct from the throttle body and spray a little carburetor cleaner, or gasoline from a syringe, into the intake manifold, then try to start the engine. If the engine catches and then stalls, the problem is fuel delivery (pump, filter, injectors). If it doesn't respond at all, the problem is spark or compression.
  9. Check the condition of the timing belt (on the QG18DE it is a chain). Remove the timing chain cover (the upper plastic cover at the front of the engine) and inspect the chain tension. A stretched chain throws the crankshaft and camshaft out of sync. The sensors may then give conflicting signals, and the ECU will block starting. A typical sign is code P0335 with sensors that test good.
  10. Check compression if the previous steps haven't found the problem. Remove all the spark plugs, screw a compression gauge into the first cylinder, open the throttle fully and crank the engine with the starter for 5-6 revolutions. Repeat for every cylinder. Normal compression on the QG18DE is 11-13 bar, with no more than 1-1.5 bar difference between cylinders. Low compression (below 8 bar) or a large variation means worn pistons and rings, burnt valves or a blown cylinder head gasket.
  11. Check the wiring between the air filter and the left strut tower, a known N16 problem area. The wire to the ignition switch contact group runs through this area, and if its insulation chafes through, the ignition power circuit can break.

Common mistakes and warnings

  • When connecting a gauge to the fuel system, observe fire safety precautions. Pressurized gasoline ignites easily. Relieve the residual pressure before disconnecting any lines, and wrap the fittings in a rag. If the diagnosis shows low compression, the engine needs a major overhaul, so take it to a repair shop.