F355 new throttle cable | FerrariChat

F355 new throttle cable

Discussion in '348/355' started by 275GTB, Feb 20, 2017.

This site may earn a commission from merchant affiliate links, including eBay, Amazon, Skimlinks, and others.

  1. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,907
    London
    Full Name:
    Mark McCracken
    Hi, just dealing with the classic sticky throttle problems on my 355 - going through all the usual fixes as we speak.

    I have bought a new throttle cable, just looking for some guidance or tips before i start to fit it.

    Does anyone have a guide of how to do it, cant find anything in the workshop manual?

    The throttle cable runs behind the petrol tank, in a fixed metal tube - do i need to remove the petrol tank for access or is there a way of doing it without removing the tank - feeding the new cable through by attaching to the old cable?

    Do i have to have the car on a ramp to fit the new cable or can it be done from the deck?

    Any advice, guidance or tips greatly appreciated.

    many thanks
    Mark
    1997 355 5.2 motronic
     
  2. Dave rocks

    Dave rocks F1 World Champ
    BANNED

    Nov 23, 2012
    16,047
    Orchard Park, NY
    Full Name:
    Dave Lelonek
    You do not need to remove the tank. The cable connects to the throttle bell crank. I suggest disconnecting it and see if it moves freely.

    The problem could be:

    - Dirtly pedal pivot mechanism
    - cable (doubtfull)
    - siezed bell crank bearing (I had this problem)
     
  3. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,907
    London
    Full Name:
    Mark McCracken
    thanks Dave,

    can the old cable just be removed and the new one feed through - or should i connect the new to the old and pull through?

    I have replaced the 2 roller bearings at the throttle pedal and the 2 on the linkage behind the carpet. Also checked the carpet for fouling the movement where the connecting rod passes through.

    I have new roller bearings to go on to the pivot shaft of the quadrant, i also have 4 new rose joints to fit on the two rods.

    I am beginning to suspect the cable or the quadrant parts, as the problem gets worse as the engine gets hotter - i am thinking that the heat is making the moving parts around the quadrant sticky as the expand slightly - also the cable runs beside the thermostat housing which gets very hot.

    Happy to go through all the above, and if its not fixed then, I think it can only be the butterflies on the throttle bodies creating an uneven vacuum, so they will get stripped, cleaned and re-balanced.
     
  4. Dave rocks

    Dave rocks F1 World Champ
    BANNED

    Nov 23, 2012
    16,047
    Orchard Park, NY
    Full Name:
    Dave Lelonek
    #4 Dave rocks, Feb 20, 2017
    Last edited by a moderator: Sep 7, 2017
    Mark - I've heard the "quadrant" term several times but not sure I understand what part this is. I know the cable goes inside a metal tube, but if it's fastened anywhere I cannot say.

    Again, I suggest you disconnect it from the bell crank and see if it operates freely. Here is the issue I had with the bellcrank bearing...

    BTW - I've read (can't confirm or deny) that the sticking can happen because of the throttle bodies.
    Image Unavailable, Please Login
    Image Unavailable, Please Login
    Image Unavailable, Please Login
     
  5. cuneo

    cuneo Formula 3
    Silver Subscribed

    Nov 20, 2006
    2,428
    My car had really bad sticky throttle. New motor mounts fixed it, the whole engine had sagged down to the point of pinching the cable somewhere. Sorry if you've checked this already!

    Good luck sorting this, it will transform your enjoyment of the car.
     
  6. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,907
    London
    Full Name:
    Mark McCracken
    Thank you, new engine mount were fitted last month when i had the engine out, so hopefully another possible culprit crossed off!

    thanks
     
  7. hjp

    hjp Formula Junior

    Feb 23, 2013
    591
    Kansas City, Mo.
    Full Name:
    Jerry Peterson
    Check this out in the threads above. Its current. I never knew there was a later model "quadrant" (or bell crank). Not sure exactly when in '97 this change occurred but this may be your as well as many other's problem, mine too ('96 Spider).

    Anyone know where to get the later model or, if available (haven't checked yet) is this the only one available now. Anyone know who can reliably mod the old ones as mentioned in the other thread?

    Go to first new post F355 Updated Throttle quadrant
    275GTB
     
  8. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,907
    London
    Full Name:
    Mark McCracken
    yep i started that thread as well
     
  9. 275GTB

    275GTB Formula 3

    Jan 12, 2010
    1,907
    London
    Full Name:
    Mark McCracken
    hi, just a bump to get the thread back on track....

    new throttle cable, just looking for some guidance or tips before i start to fit it.

    Does anyone have a guide of how to do it, any advice, guidance or tips greatly appreciated.

    many thanks
    Mark
    1997 355 5.2 motronic
     
  10. scrappin35

    scrappin35 Karting

    Dec 13, 2011
    187
    FT Lauderdale
    Full Name:
    Jim H
    Mark... I would suggest the same thing Dave pointed out. My throttle was sticky as well and at one point stuck open as I was accelerating. ( I had kill the engine and pull over). I lubricated the bell crank and now its silky smooth. Easy fix if you haven't done it yet. I have not replaced the cable so can't offer any advise on that.

    good luck
     
  11. hjp

    hjp Formula Junior

    Feb 23, 2013
    591
    Kansas City, Mo.
    Full Name:
    Jerry Peterson
    I have a new cable, have oiled my bell crank and checked to make sure everything is free but there is still a very slight stick after the car has fully warmed up (when cold there is no sticking). This occurs at the very beginning of the pedal movement and if I just exert modest pressure for a second or two rather than pushing hard, it will get past the sticking. Makes it a little touchy to drive sometimes but still OK.

    If a new bell crank will fix the problem permanently, hot or cold, I'd definitely do it but not at $400 (best price from Eurospares so far). Not having seen it in this light, not sure what the mod might cost.
     

Share This Page