Long starting cranking (it does not happen every time, but it starts)

Mike_Imp_12Mike_Imp_12 Member Posts: 3
edited November 2021 in Subaru
Hi all, and thanks in advance for any help

Car: 2012 Subaru Impreza, 2.0L engine, Automatic (CVT), 132xxx KM.

Issue: Sometimes (randomly) it cranks for long time before starting (but it does start at the end). This happens randomly so sometimes it starts right away, other times it keeps cranking then it starts. No dash light at all, no codes at all (I checked with MaxiSys mechanic scanner and Bluedriver scanner).

Recent maintenance:
1- Early 2019 (@122xxxKM), Subaru dealer did 2.0L engine (the famous) recall + changed all 4 spark plugs + oil and oil filter change
2- Summer 2020, bank 1 oxygen sensor (few dash lights were on then turned off after the repair)
3- July 2021, oil and oil filter change + new air filter.
4- October 2021, new accessory belt + new idler pulley
5- Checked battery (12.6V, 85% good) and alternator (14.3 as far as I remember)
6- Cleaned throttle body
7- Added 1x STP fuel injectors cleaner to a full tank (it is about 40% full now)

Notes:
1- I do hear the fuel pump working every time when I turn key on ON position

Thanks in advance for any advice.

Comments

  • thecardoc3thecardoc3 Member Posts: 5,519
    edited November 2021
    How long is the "long crank" event when it does happen?
    Five seconds?
    Ten seconds?
    Longer?

    How many days are typically between events?
    What are the odds in favor of it acting up if you leave it at a shop on any given day?

    When it occurs how was the car used on the previous trip?
    How long did it sit before attempting the restart?
    Does touching the throttle while cranking (maybe 1/4 throttle to 1/2?)
    Have you ever tried full throttle while cranking?

    What are the ambient conditions like when it occurs, can you discern any pattern to the event?
    Rain?
    Temperature?

    These are the things that I would need to know in order to start testing. Being able to hear the fuel pump is good, but do you know what the fuel pressure is when it acts up?

    Can you test for spark and injector pulse when the problem happens?

    Are there any codes setting in any module? (theft deterrent)
  • Mike_Imp_12Mike_Imp_12 Member Posts: 3

    How long is the "long crank" event when it does happen?
    Five seconds?
    Ten seconds?
    Longer?

    How many days are typically between events?
    What are the odds in favor of it acting up if you leave it at a shop on any given day?

    When it occurs how was the car used on the previous trip?
    How long did it sit before attempting the restart?
    Does touching the throttle while cranking (maybe 1/4 throttle to 1/2?)
    Have you ever tried full throttle while cranking?

    What are the ambient conditions like when it occurs, can you discern any pattern to the event?
    Rain?
    Temperature?

    These are the things that I would need to know in order to start testing. Being able to hear the fuel pump is good, but do you know what the fuel pressure is when it acts up?

    Can you test for spark and injector pulse when the problem happens?

    Are there any codes setting in any module? (theft deterrent)

    Thank you so much for the reply,
    Here is what I was able to conclude. The issue (long cranking time) happens, usually, when I drive the car for a while then park it (for about 2 hours) then attempting to start it. Here is how I came up with this conclusion ; I go visit a friend around 9pm (about 30 minutes of driving so the car is in fully operating temp), I park the car, then at about 11'sh pm I attempt to start the car, and it cranks for about 3-4 seconds, then it starts. I have a video of that (not sure if I can upload it here).
    Please note that:
    - It starts just fine when it is cold (example in the morning)
    - It starts normally when I shut then start again (example filling up gas). The mechanic did turn on and off to test the battery; he tested it about 4 times in a row, and it started right away every time. So he was not able to reproduce the issue.
    - I am not sure about the spark plugs as they were changed by Subaru dealer about 10000km ago. Do you think one of them is bad ?

    " Does touching the throttle while cranking (maybe 1/4 throttle to 1/2?)"
    - Can you please elaborate more on this point ? Name f the test so I look how it is done ?

    " Have you ever tried full throttle while cranking?"
    - I will try this test. What do I expect in normal condition ?

    "These are the things that I would need to know in order to start testing. Being able to hear the fuel pump is good, but do you know what the fuel pressure is when it acts up?"
    - How do I check the fuel pressure without a pressure tester ? I think I will need the pressure tester. I have Bluedriver OBD, will see if it gives live data for fuel pressure.

    "Are there any codes setting in any module? (theft deterrent)"
    - No error codes at all. I used the mechanic MaxiSys scanner and BlueDriver OBD.
    - I start doubting the key battery. May be it does not send good signal...I donno.


    Thank you,
  • Mike_Imp_12Mike_Imp_12 Member Posts: 3
    I uploaded the video on my friend's YouTube channel
  • thecardoc3thecardoc3 Member Posts: 5,519
    When you start cranking the engine, if it isn't running in the typical two seconds or less, start stepping on the gas pedal about one quarter of the way (like a normal acceleration) up to about half throttle (a hard acceleration but not full throttle)

    The idea of those is to see if doing that gets the engine to start a little faster.
  • Edge87Edge87 New YorkMember Posts: 37
    Best place to start is to check fuel pressure while cranking to rule out a fuel system/pump issue
    Next is to use your scanner and view live data while starting/cranking.
    I see the battery and alternator were checked to be ok. How are the cables going from the battery, alternator and starter? Poor Connection/High resistance can cause your issue as well.
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