Car startup issue

Discussion in 'Car Talk' started by brokenjars, Jan 8, 2020.

  1. brokenjars

    brokenjars 5 Year | Silver

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    My car if shutoff for too long it will have this one small issue. Basically after shutoff for >8 hours, on first start up it will always die immediately if i didnt press the gas a bit. To prevent this everytime after shutoff for more than 8 hours, when i turn the key need to give it a bit of gas then only ok.

    If shutoff for short period, this issue wont happen. Any thought?

    Car is a nissan sentra with na sr20ve engine.

    Thanks
     
  2. lsm1991

    lsm1991 Senior Member
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    does your car have any sort of icv? sounds like a cold start issue.
     
  3. brokenjars

    brokenjars 5 Year | Silver

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    I dont think its the icv issue. The car idles fine during cold or after warm up. Very solid idle. Just the first start up after sleeping too long it will stumble. Also the car starts easily everytime.
     
  4. lsm1991

    lsm1991 Senior Member
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    fuel pump possible? try leave the car in on for abit before cranking?
     
  5. brokenjars

    brokenjars 5 Year | Silver

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    Yeah tried that. Also same.
     
  6. leinnz

    leinnz Senior Member
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    what was change recently before the issue happen?
     
  7. vr2turbo

    vr2turbo 5 Year | Silver
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    My VR same problem for years already, so just need to gas a bit then will idle properly.......lol
     
  8. brokenjars

    brokenjars 5 Year | Silver

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    Since last time is like that hahaha. Even after full overhaul last year also like that lol. Suspect is nozzle clogged or leaking (where to do nozzle ultrasonic In penang?)
     
  9. brokenjars

    brokenjars 5 Year | Silver

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    At first i dont mind, now kutip habis the car d, focus on this small small things pulak lol
     
  10. Izso

    Izso Boooooossst
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    Does your SR20 transplant come with a coolant temperature sensor? What ECU are you using? There's two possibilities I can see that's causing this.

    1. A faulty coolant temperature sensor that's reading wrongly during cold start hence when you give it some gas the thing straightens out. Once the car is going you're able to idle without holding the gas? You only need to blip the gas?

    2. A faulty or going to be faulty fuel regulator and/or fuel pump. How old is your regulator and pump? Maybe it's just time.
     
  11. brokenjars

    brokenjars 5 Year | Silver

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    1. Comes with coolant temp sensor. Reading is correct so far, after idle 1-2 minute the temperature will slowly goes up. The car idles fine even when very cold. Just when starting give it a blip of gas, and it will start right up and idles fine. If didnt give blip it will crank a bit more, around 6 turns before start n dies immediately after. Normal crank turn only 2-3 times.

    3. Ecu is sr20ve p11 ecu piggyback emanage blue. Originally this engine pairs with sr20ve p12 ecu from factory.
     
  12. Izso

    Izso Boooooossst
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    I am not familiar with the P11/12 ECU so can't comment but I suspect it has something to do with that. Cold-start is all the ECU and what sensor data it picks up. So if the coolant temp sensor is working then it might be the parameters of the ecu itself since it's not the original P12? I dunno. Is there some setting in he emanage you can check to check the cold-start?
     
  13. brokenjars

    brokenjars 5 Year | Silver

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    Well even at overseas it is common to switch to p11 ecu when plonking the engine down to sentra b13, because they do not know how to retain the original coil on plug ignition system, so need to switch to distributor type. Hence the change of ecu.

    For the emanage, i have no knowledge on how to tune it..
     
  14. gunnerzz

    gunnerzz 5 Year | Silver

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    On my old Pajero, adding grounding cable solve the problem. Starts easily when cold.

    When hot, need to crank a bit longer.
     
  15. brokenjars

    brokenjars 5 Year | Silver

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    Ah i faced this problem before on my previous toyota with 4age blacktop engine. My current problem symptoms are not the same..
     
  16. sweelt

    sweelt Well-Known Member

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    wild guess, was your fuel pump priming when key ON ?
     
  17. brokenjars

    brokenjars 5 Year | Silver

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    can hear it prime for 1-2 seconds then quiet. Tried after prime immediately turn, after prime 20 seconds only turn, no wait prime immediately turn, all can start the car. Also all same result, the car will die immediately afterwards. Very rarely it will stumble till almost 0 rpm then somehow manage to go back up the rpm and idle.
     
  18. Izso

    Izso Boooooossst
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    I still think this is something to do with the coolant temp sensor and your ECU. Cuz warmed up the car no issue - I suspect the cold start management of the ECU is not working properly somehow.
     
  19. brokenjars

    brokenjars 5 Year | Silver

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    Comes to think about it, it might be the coolent temp not detected by the ecu. When started in cold, the idle is at 950 rpm. Supposed to be higher i think. After warm up, it will go down to 850.

    How do i check whether the ecu is detecting or the coolant temp is not faulty?
     
  20. Izso

    Izso Boooooossst
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    I don't think you can with stock ECU unless you have some sort of diagnostic tool. And you're right, cold idle is usually higher.

    You mentioned you changed your coolant temp sensor recently right?
     

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