2015 wrx sti won’t start

[Robert kennedy]

My 2015 wrx sti won’t start Battery is ok and fuel pump is working. The engine cranks over but won’t start anybody got any ideas. Thanks for the help in advance Rob.

[SF5Fozzi]

Are your camshaft & crank sensors getting a signal when you turn it over?

[savage bulldogs]

Does the Battery and eml come on when you turn the key ? 

If not try ignition fuse in the cabin 

Check the crank and cam sensors wires and plugs .

Do you know if you have spark ?

[SF5Fozzi]

@savage bulldogs ,

If the ignition fuse was blown then the fuel pump would not prime👍🏻

[savage bulldogs]

Not sure if it just cuts spark on the later models or whether fuel prime and supply are also both on the same circuit. 

My electrical knowledge is limited to v1 to v4 but thought it was worth a shout if he had no Battery and eml .

 

 

[Jay762]

Do you have any error codes?

[Robert kennedy]

No

[SF5Fozzi]

Long shot...., but try this out.

Make sure you got voltage in the Battery. Then disconnect the wires at the alternator. 

Try starting it. 

If it starts then the alternator's bad. Sometimes the alternator can appear to be operating properly but it can send a disruptive signal to the camshaft sensors that can cause a no start issue. 

Worth a try🤔

[D3lux]

Usual diagnostic flow would be....

1. Is it turning over ok? Too slow=battery, dodgy starter, dodgy earth, something siezed. Too fast=no compression, snapped timing belt. Flashy lights=immobiliser?

2. Is it getting a spark? You need sparks and fuel. If you check for fuel 1st and you are getting fuel you need to clean it up. If you drop the spark plug you dont spill electricity everywhere! Fuel pump noise isnt good enough because you dont know if its pumping it out, you dont know if the ecu is opening the injectors.

Now you have established the basics you can check for fault codes, check alternator output, check fuses, check timing, check for gypsy curses/demons etc.