Stw car mechanics assemble – nissan note starting issue

Mrs has a 2014 note, 1.2 3 cylinder petrol.  It has developed an intermittent starting problem – it will just fail to start, either after stopping on stop/start or with the key. No apparent reason. Turn key, faint click and then nothing. No warning lights on dash, no error codes on scanner etc.  When it does turn over, it’s really lazy but does start (never had a 3 cylinder car before so don’t know if this is normal).

So far:

New battery

Refurb starter motor

Cleaned up earth points and reattached cables.

Any suggestions (whilst we wait for the local auto electrician to fit us in!)

Alternator

I did check the charging with a meter and it seemed ok (as in, voltage went up after starting).

Crankshaft or camshaft sensor potentially. Probably into guessing games and parts cannon time at this point unless you get a really good auto electrician who can actually diagnose things logically with a scope and voltmeter.

Starter relay if there’s one that’s not part of the refurbished starter.  Was it any better after the battery swap and then got worse?

Scruffy – yes it did, thinking about it.  Battery voltage (standing) seemed ok last time I checked it though

You need to be keeping an eye on the voltages at the starter itself to make sure the voltage isn’t dropping when the starter is cranking indicating a duff battery cell.

Next is to check the voltages between the engine block and bodywork to see if there’s any floating voltage that would indicate a dodgy earth. Also use a jump lead from the engine block to bodywork to dismiss the earth cables.

If voltages and the earth cables are good then if it happens that the starter ‘clunks’ but doesn’t operate then it’s the starter solenoid that’s moving but isn’t making good enough contact that it powers the starter motor itself.

If the engine is spinning over quickly on the starter but not firing then it’s crank/cam position sensors or immobiliser circuits.

Decent quick acting multimeter and an assistant required.

Knackered starter motors can be an indication of a rapidly failing dual mass flywheel – the magnetised elements of the starter motor are attracting the dwarf from the DMF that then kills the starter especially the case if it’s had two starters in quick succession.

Dwarf Mass Flywheel?

Cheers RNP – most of that way beyond me if I’m honest 🙂

As the issue has persisted over a battery and starter change, I suspect it probably isn’t a dmf problem (hopefully anyway!). Dodgy electrics somewhere I hope – wondered if it might be the clutch position switch, but that wouldn’t make it lazy to start.

Swarf!!!!!!!!

If it’s cranking then the starter circuit is okay (ignition switch etc).

Eliminate potential earth cable issues by clipping a jump lead/cable from the engine block (anywhere nice and clean unpainted metallic on the engine) to the negative of the battery and try starting the engine.

Isn’t there a test which involves a jump lead from the positive pole on the battery direct to the starter . If it cranks over properly then it’s wiring between the ignition switch and starter motor.
Think it can get excitingly sparky though , so best get the misses to do it.

Cheers RNP, I’ll give that a whirl 👍

Ignition switch itself can fail in the sector energised when turning key against spring