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Mondial "hesitation" under acceleration

Discussion in 'United Kingdom' started by tomkranz, Mar 2, 2004.

  1. tomkranz

    tomkranz Karting

    Dec 22, 2003
    152
    Berkshire
    Full Name:
    Tom
    When swiftly making way on the Queen's highway, the Mondial has started to hesitate when pushing through the rev range.

    Given it's been serviced fairly recently, I'm inclined to think the somewhat ratty exhaust is starting to enter the 'colander' phase of it's life.

    I know in a lesser car, holes in an exhaust have this effect (reduction in back pressure etc. etc.) - however, does the same thing still happen in Ferraris?

    Given the short and business like nature of the exhaust, if it was becoming a 'holy relic' would it be as noticable?

    (And, yes, that should probably be under the "Dumb questions you're afraid to ask" thread :)

    Just looking for areas to examine in more detail before forcing open the wallet.

    Cheers,
    TOM
     
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  3. tifosi

    tifosi F1 Veteran
    Lifetime Rossa

    Sep 5, 2001
    5,382
    texas
    Full Name:
    Tom D
    I think you need to provide more details, is it also making noises consistent with an exhust prob, does it hesitate all the time? what service was recently done, did you go to a diff gas station - ie bad tank of gas, did they recently change the fuel filter, fuel pump etc? has your fuel system/injectors recently been cleaned
     
  4. tomkranz

    tomkranz Karting

    Dec 22, 2003
    152
    Berkshire
    Full Name:
    Tom
    Good call.

    Noise is difficult to judge - it's always noisy :) I shall leave her to idle when warm and wander around the back end to see if there's anything specific.

    Only hesitates under hard acceleration, recent service was a full + cams, done around 1k miles ago.

    Had a recent full tank of petrol, from the same garage I usually use, and the same tank load of Shell Optimax.

    Doh! Fuel injection! Spent too many years driving old Rovers - I was thinking "Oh, maybe the carbs need balancing".

    That's actually quite humiliating :) I shall get the injectors looked at.

    Thanks for the ideas,
    TOM
     
  5. Robertb

    Robertb Formula 3

    Nov 19, 2003
    1,330
    South Oxfordshire, U
    Full Name:
    Robert
    Is it a hesitation as in slight drop in power, or hesitation as in momentary total loss of power.

    If it is the latter, my 328 had that for a bit, and I believe it was because I left it outside in very heavy rain and some electrical bit got damp. The problem became less frequent and eventually disappeared.

    Not technical enough to be able to offer any other advice...

    Robert.
     
  6. tifosi

    tifosi F1 Veteran
    Lifetime Rossa

    Sep 5, 2001
    5,382
    texas
    Full Name:
    Tom D
    I put in techron (from chevron) fuel injection cleaner in a tank of gas every couple of months to keep the fuel system and injectors clean. also make sure the throttle cable is not getting hung up, ie try to rev it from the engine bay to see if the hesitation is still there. it could be any number of things that is why you need to eliminate the easy things first before tearing it and your wallet apart :)


    here is an old thread on the stuff

    http://www.ferrarichat.com/discus/messages/256120/95425.html
     
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  8. tomkranz

    tomkranz Karting

    Dec 22, 2003
    152
    Berkshire
    Full Name:
    Tom
    Thanks for the ideas, chaps.

    RobertD - it's a slight drop in power. Accelerating hard (is there any other way? :) and there'll be a slight pause, then the revs climb again, another slight pause.

    Nothing major, but it's noticeable.

    tifosi - thanks for the FI ideas. I'll hunt down some decent cleaner and bung it in the tank.

    Any excuse to drive around :)

    Thanks again chaps - I'll let you know how I get on.

    Cheers,
    TOM
     
  9. mario308

    mario308 Karting

    May 15, 2001
    61
    UK
    Hi Tom,

    I don't think the exhaust would make much difference, I once drove back from Brands hatch with the left hand exhaust tube bend (just before it enters the silencer) sheared off near where it meets the flange!! No loss in power, accel etc although I was deaf for an hour or 2 afterwards.

    I've also had cracked manifolds & it didn't effect it.

    I did have a similar problem to yours and traced it to the spark plug extenders I had found 3-4 of them had gone open circuit, they are the red tubes under the plug leads on top of the spark plugs.

    Check them out as they should have a resistance - I think a few k Ohms (data @ home) - Plus they are easy & cheap to isolate / replace.

    If it's a significant amount of power and in my case erratic tacho reading then it's probably one of the famous ignition sensors near the flywheel.

    The Mondial QV has 3 in all 1 for TDC I think & the 2 others are for each bank, one had died on my car so it became a 4 cyl engine but still drove ok.
    The one I replaced was located at the 11 O'clock position as you look through the wheel arch.

    Good luck,

    Mario.
     
  10. Philjay50

    Philjay50 Formula Junior

    Jan 16, 2003
    594
    Chester, England
    Full Name:
    Philip
    I had the same problem with the sensors, but in that case one bank went off.
    Is it possible that the vacuum pipe has become detached, broken, etc. This would affect the advance of the ignition giving a smallish power loss.
     

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