Intermittent start issue used 2013 subaru impreza

Maintenance/Repairs
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What is going on guys. Owner of a used 2013 Subaru Impreza 2.0i. When I purchased the vehicle approximately 7 months ago with 149,000 miles, the buyer told me about a start problem occasionally. In the past 7 months I have experienced the no start issue approximately 15-20 times. The engine will crank, but will not start. When you turn the key to off and then try to start again, it will start everytime. Of the 15-20 times of experiencing the issue, about 3 of those times It did not start after turning the key to off position. However the third time you go to start it started. I have not noticed that it happens at specific times or specific weather. Its very random, and my dad has a Snap on triton d8 with updated software, and was unable to pull any codes. Ive seen my father multiple times to try and pull codes. Im am asking for any ideas or thoughts on what the potential issue is. I am leaning towards a failing starter, and after you see my list of Maintenance I have preformed myself, maybe you could give me other directions I could look? LIST OF COMPLETED MAINTENANCE

  1. Resealed transmission pan and replaced transmission oil
  2. Drain and replacement of front and rear differentials
  3. New battery
  4. New spark plugs
  5. New PCV valve
  6. Intake mainfold cleaning and throttle body gasket replacement
  7. Subaru’s engine maintenance kit completed
  8. New MAP sensor installed
  9. MAF sensor was cleaned thoroughly with MAF cleaner
  10. Replaced and resealed driver and passenger side valve body gaskets as it was leaking quite a lot of oil into my spark plug tubes
  11. Replaced spark plug tube seals when preforming Valve body gasket replacment
  12. New fuel pump and filter
  13. Driver side broken EARTH ground was replaced
  14. Replaced Fuel pump relay
  15. Installed new crankshaft position sensor last weekend (had one no start this week, but other then that starts fine)

I am currently looking at any ideas or any thoughts of what the potential culprit of this problem could be. I need to go over to my fathers to try and use the Triton to scope my vehicle and gather data about the where the problem lies. I am leaning towards a failing starter as my car has 154,900 miles on it and im assuming the starter has never been replaced. Other then that I am down to potential bad grounds from a wire somewhere, or cam sensors. I would appreciate any input on this problem as it is not causing me to much trouble but its been somewhat fun chasing this problem and also its just frustrating sometimes it happens but never throws a code. I appreciate you for reading this long text, thank you.

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If the engine cranks, it’s not the starter.

A faulty crankshaft position sensor can cause an tntermittent no start.

Tester

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Well Im an ass and forgot to mention I just replaced my crankshaft position sensor while doing the my valve cover gaskets last weekend. So maybe fault camshaft position sensor?

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That can also cause intermittent no start.

Tester

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Maybe a worn out ignition switch?

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I’m thinking you have a fuel rail pressure problem. The fuel pressure isn’t holding like it should when you turn the key off. It’s either leaking back into the tank (fuel pump problem) or a fuel injector is leaking fuel into the engine.

One thing is very likely, problem is either spark or fuel related. If you have a way to check for a visible spark at a spark plug, you could do that experiment at a time when the engine cranks but doesn’t start. Unfortunately that experiment became more difficult for driveway diy’ers with the introduction of coil-on-plug ignition system designs. The alternative test for the fuel system is a fuel pressure hold test.

Some engines use a fuel pressure regulator usually located at the end of the fuel rail. Probably doesn’t apply to a 13 Impreza. But if so equipped, remove its vacuum line. There should be no fuel come out.

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