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gen 3 runs with only gasoline engine after cleaning throttle body and intake

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by redprius2011, Mar 26, 2024.

  1. redprius2011

    redprius2011 Junior Member

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    i just cleaned intake and throttle body just like a new 0% carbon or oil build up, replaced PCV and intake manifold gasket, after all this car starts very rough when cold but accelarating so much better, sometimes EV mode doesn't kicks on and stays with ICE running, also engine rpm increases when breaking, i have a tuned ECU and injen cold air intake but my tuner did everything when intake and throttle body was clogged in carbon, now its completely clean and its sucking more air in it, maybe it needs to correct the AFR again? the MAP sensor was swimming in oil and what spray cleaner can i use to clean it?
    BTW EGR is not cleaned yet but before that it was working normally.
     
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Whats the miles?

    Having the intake manifold off, presumably you cleaned it?

    Recheck all the hoses and electrical connectors.. If either the pcv or gas vapour hoses were disconnected I think it'd shut right down and throw a code though.

    Did you pull the coolant lines off the throttle body?
     
  3. ChapmanF

    ChapmanF Senior Member

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    If a Prius MAP sensor can say what the pressure is while swimming in oil, I wonder if there's any need to do anything to it.
     
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  4. whitrzac

    whitrzac Junior Member

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    Who tuned your ecu?
     
  5. redprius2011

    redprius2011 Junior Member

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    i cleaned it like a new, small build up still left on only EGR holes but nothing serious, all the hoses and connectors is checked no issues, car throw cyl 1 missfire code, also intake manifold bolts and nuts is torqued in spec 21lb ft and intake gasket is OEM aswell.
     
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  6. redprius2011

    redprius2011 Junior Member

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    3-4 PSI on full load, 13-13.5 idle. thats what obd shows.
     
  7. redprius2011

    redprius2011 Junior Member

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    i live in Georgia (country in europe) very well known guy tuned my car, he knowns his job.
     
  8. redprius2011

    redprius2011 Junior Member

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    141K miles on it, yes i did pulled throttle body coolant hoses.
     
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  9. redprius2011

    redprius2011 Junior Member

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    spark plugs is like a new, i have changed it 2-3 month ago, i have to swap ignition coils from cylinder 1 to cylinder 4, If it gave me an error on the fourth cylinder, this means that ignition coil needs to be replaced.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    That sounds flat-out backwards. Are you using a scan tool that tries to convert absolute pressure to gage pressure for some reason?
     
  11. Mendel Leisk

    Mendel Leisk Senior Member

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    For next time, consider not disconnecting those coolant lines; they have plenty of slack, enough that you can clean it leaning over the engine bay.

    anyway: maybe air pockets in coolant are a factor?
     
  12. redprius2011

    redprius2011 Junior Member

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    if i dont disconnect coolant lines, how should i remove intake manifold assembly to completely clean it?? i think i have air leak.
     
  13. redprius2011

    redprius2011 Junior Member

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    its just says "intake manifold absolute pressure" on idle it shows 13-14 psi, when i floor accelerator then it goes to 3-4PSI at 2500rpm thats max rpm while u're in P.
     
  14. ChapmanF

    ChapmanF Senior Member

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    Something isn't adding up here. About 4 psi absolute would be a believable number at idle; the throttle is barely open then and the manifold pressure is that low. 13 to 14 psi at idle is bewildering.

    The reading at 2500 RPM doesn't really look wrong. When the car is just sitting there and you increase the RPM to 2500 in Park it is really not doing much work, and that MAP reading should look pretty close to a normal idle reading.

    Which it does. It's only your idle reading that doesn't look close to a normal idle reading.
     
  15. redprius2011

    redprius2011 Junior Member

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    can u recommend any android software to test intake manifold pressure?? maybe my scanner software reading wrong.
     
  16. Mendel Leisk

    Mendel Leisk Senior Member

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    Remove throttle body hold-down bolts/nuts, lift off throttle body with coolant hoses still attached, shift it over towards inverter and tie it to the conduits there with twine or what have you.
     
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  17. redprius2011

    redprius2011 Junior Member

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    i will check it again without going in ready mode, just ignition ON only, TB is clean just like a new i don't think this is stuck open, should have throw error code then.
     
  18. redprius2011

    redprius2011 Junior Member

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    ignition on only 13.49 PSI, throttle at ~18% open.
     

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  19. ChapmanF

    ChapmanF Senior Member

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    At 0 RPM, the MAP reading should be a pretty good match to your local weather station's barometer.

    13.49 psi is about 93 kPa. What's your local weather station say? 93 kPa seems lowish.

    If it doesn't drop significantly lower than that when the engine idles, maybe you have a leak into the manifold, beneath the throttle body, or elsewhere.
     
  20. redprius2011

    redprius2011 Junior Member

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    9c, 48F, it doesn't drops when starting the engine.
    102.3Kpa pressure