348 throttle position sensor adjustment | Page 2 | FerrariChat

348 throttle position sensor adjustment

Discussion in 'Technical Q&A' started by ernie, Jul 10, 2014.

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  1. ernie

    ernie Two Time F1 World Champ
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    #26 ernie, Oct 20, 2014
    Yes.
     
  2. 348Jeff

    348Jeff Formula 3

    Oct 25, 2011
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    #27 348Jeff, Oct 25, 2014
    I don't think you can swap the seats but when I had mine fixed the upholster swapped over the the outer covers/upholstery to even out the wear.
     
  3. ozziindaus

    ozziindaus F1 Veteran
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    #28 ozziindaus, Oct 26, 2014
    I think the big question is why did your TPS need adjustment?
    Has the throttle angle changed (set screw moved or cam peened onto screw)?
    Did the shaft tab wear out the TPS button (rotating interface)?

    In regards to Idle Air Control Valves, they are always working to keep idle regardless of engine temp. i.e. air density, engine load, aircon on/off etc. They are even used to dampen rapid throttle closure. If you haven't tampered with your Idle set screw, then high RPM at idle is typically indicative of a leak somewhere downstream of the throttle.
     
  4. Triple Black

    Triple Black Karting

    Feb 8, 2014
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    #29 Triple Black, Nov 26, 2014
    Make sure the electrical connections on the mass air flow sensors are working. I had a bad idle issue and I wiggled the right side engine connector and the idle came back to 1K RPM.
    Use stablant 22 from Ricambi on the connectors after cleaning to help make good connections. Worked for me!!!
     
  5. Full

    Full Karting

    Feb 21, 2010
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    Alessandro
    #30 Full, Jan 3, 2015
    GOOD MORNING!
    ERNIE HELLO HAPPY NEW YEAR!
    FRIEND, DID ALL PROCEDURES EXPLAINED HERE, REALLY MY PARAMETERS WERE ALL OUT OF NORMAL, BUT STILL MY IDLE OSCILLATING CONTINUES!
    WHAT YOU THINK STILL miss DO OR WHERE WOULD THE PROBLEM?
    HUG!
     
  6. Full

    Full Karting

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    #31 Full, Jan 3, 2015
    HELLO AGAIN ERNIE !!
    FRIEND, HOW AM USING THE TRANSLATOR MANY WORDS OR TECHNICAL TERMS NOT LEAVE RIGHT!
    ON THESE PROCEDURES REPORTED HERE, YOU HAVE PHOTOS FOOTSTEPS?
    THANK YOU!
     
  7. ernie

    ernie Two Time F1 World Champ
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    #32 ernie, Jan 3, 2015
    Try having the ecu's (computers) relearn the intitial start up parameters. Disconnect the battery for 1 minute, then reconnect it. With all the accessories turned off, and gearbox in neutral, start the engine and let it ilde. Do not touch anything, just let the car sit and idle for at least 15 minutes. After the car has idled for 15 minutes take it for a 30 minute drive.

    The reason the ecu's need to be reset is, they take the initial readings from the throttle position sensors and use those readings to determine what engine mapping to use. Since you changed the resistance of the throttle position sensors the ecu's are calculating the mapping based on the old tps settings.

    So.........

    Anytime you change the tps settings you will need to disconnect the battery and let the car go through the initial start up parameters.
     
  8. Full

    Full Karting

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    #33 Full, Jan 3, 2015
    OK ERNIE!
    VERY GRATEFUL FOR YOUR TRADITIONAL CORDIAL ATTENTION!
    HUG!
     
  9. ga68

    ga68 Karting

    May 22, 2014
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    Gaëtan
    #34 ga68, Jan 21, 2017
    Hello Ernie
    A big thank you for all your research and sharing.
    I have a question about the reference "0280 122 004".
    I have a 348 from 1993 and the référence is "0280 122 001" is this normal?
    Other owner in the same case as me or an error on my car?
     
  10. ernie

    ernie Two Time F1 World Champ
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    #35 ernie, Jan 21, 2017
    It's probably the replacement tps, the upgraded newer version. Some times the manufacture discontinues making a part but has another part that fits the specs.
     
  11. ga68

    ga68 Karting

    May 22, 2014
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    #36 ga68, Jan 21, 2017
    Thank you Ernie for this answer, hoping that other possessor, can give me their references.
    This could help to identify the differences between the date of release, except for a poor repair on my 348.
    Other info, I have the screws with a yellow paint, as if they were sealed of origin.
    I discover my car from your post.
    (Google Translate)
     
  12. sas92

    sas92 Rookie

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    #37 sas92, Jul 8, 2019
    Hello Ernie . great information. You don’t mention the click noise when you adjust at the rest position. do you adjust when the click is heard or go further ?
    My 348 is a Motronic 2.5. Have you ohms values for my TPS . There’s only one TPS on a 2.5.
    Thanks for the information you could give me . Maybe other people have this information about the click and ohm
     
  13. ernie

    ernie Two Time F1 World Champ
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    #38 ernie, Jul 9, 2019
    I don’t know what “click” noise you are referring to. I adjusted mine purely based on the ohm resistance I stated on the first page. I don’t have the values for the 2.5 Motronic, so I can only assume they are they same. You may want to have a look in the shop manual for a ‘89 348, with the 2.5 Motronic, to see if you can find what the resistance values are.
     
  14. sas92

    sas92 Rookie

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    #39 sas92, Jul 9, 2019
    Hello thanks for answer I give on YouTube at 5.33 mn the famous klick. « DIY: BMW Throttle Position Sensor ». Does mean you are at the rest idle?
     
  15. ernie

    ernie Two Time F1 World Champ
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    #40 ernie, Jul 9, 2019
    I don’t think I have ever payed attention to listening for a click. I only based what I did on the ohm resistance reading. The only click I have listened for is that of the throttle stop on the bottom of the throttle body.
     
  16. sas92

    sas92 Rookie

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    #41 sas92, Jul 9, 2019
    Here’s the Bosch information:
    "For a Bosch TPS (less common):
    o Hold the throttle plate lever closed.
    o Rotate the TPS counter-clockwise until the click is heard.
    o Continue to rotate counter-clockwise until the TPS hits the end of travel (any further and it would need to open the throttle plate) then lock in place."

    So I’m gonna go counter-clockwise and go up to 1 ohm. What do you think?
     
  17. sas92

    sas92 Rookie

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    #42 sas92, Jul 9, 2019
    On the workshop manual there is no info in ohms.
    I ask this because my idle is sometimes 1500 and sometimes 1000.
    The tps test with a Multimeter indicates she’s dead.
     
  18. ernie

    ernie Two Time F1 World Champ
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    #43 ernie, Jul 9, 2019
    In that case here is what I would check:

    1) idle air control valves
    Make sure that they are clean

    2) throttle bodies
    Make sure that they are clean, opening and closing at the same time on both sides and contacting the throttle stops simultaneously (you may need to adjust the throttle linkage), that they are balanced (you’ll need a manometer) making sure that the idle air bypass screws are adjusted even.

    3) vacuum lines
    Make sure the lines are all in good condition and connected properly

    4) rest the Motronic ECUs
    The ECUs will need to relearn the warm up parameters. They take the initial reading of the throttle position sensor/s and they base the mapping if the reading/s
     
  19. sas92

    sas92 Rookie

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    #44 sas92, Jul 9, 2019
    Thanks Ernie. I will keep you inform ASAP.
     
  20. sas92

    sas92 Rookie

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    #45 sas92, Oct 8, 2019
    Hello Ernie. I'm coming back to you about the idle that does not come down to the decelaration. It was not the TPS but the adjustment of the intake between the two banks of cylinders.it was a very weak setting.
     
    ernie and Qavion like this.
  21. ernie

    ernie Two Time F1 World Champ
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    #46 ernie, Oct 8, 2019
    Glad you got it fixed, and thanks for the update.
     
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