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This topic contains 10 replies, has 6 voices, and was last updated by  scott brockbank 1 hour ago.

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  • #63815

    scott brockbank
    Participant
    Club Member

    I recently posted a question regarding an exhaust. Thanks for the response. I managed to source front and rear sections. But for some reason she struggles to go over 45mph. Any ideas why she won’t go any faster? As I am going to be using her for work and need to useM20.

    #63816

    brianw
    Participant
    Club Member

    Could be one of many causes .. How is acceleration up to 45? & what happens at 45, misfiring or just smooth running but no more increase ?  Is the same engine hot or cold ?  Is this a new problem (since the new exhaust, since other changes)?

    #63817

    Ken B
    Moderator
    Club Member

    Carpet under the accelerator pedal…. could be anything as Brian said need more info than that.

    #63822

    PeterDenice
    Participant
    Club Member

    Had a similar thing, the mechanical advance on the distributor was stuck. With distributor cap off try moving the rotor arm, it should rotate a bit against the springs of the mechanical advance. Mine did not the, the shaft that the rotor sits on had seized onto the main shaft. If you look at an exploded diagram in a workshop manual it should make things clearer.

    #63839

    scott brockbank
    Participant
    Club Member

    It accelerates up 45 then just sits there. After putting new exhaust system on. No spluttering or overevving.. Went over 60 with wrong exhaust for some reason! There is no carpet in at mo. Will look at that distributor suggestion as soon as get the chance. Thank you all for your help and advice.

    #63852

    Ken B
    Moderator
    Club Member

    Where did you get the exhaust ? is it a a copy of the original system or a sports type exhaust  I presume we’re also talking normal/standard 997 or 1200 engine too?

    #63861

    scott brockbank
    Participant
    Club Member

    It’s a 997. And I got both parts from a gentleman off ebay who said he deals in classic car exhausts

    #63862

    Ken B
    Moderator
    Club Member

    Well if it was fine before you changed the exhaust and presuming it is of  exactly the same type and bore size as previously fitted, and now its not fine there can only be three explanations.

    A) Something wrong with the exhaust itself, ie blockage in the silencer box.

    B) You’ve dislodged something during the fitting exercise, given you would have been working in the carb area- check linkage and carb fittings etc

    C) Extreme co-incidence something else is wrong- but only started after you fitted the exhaust.

    #63867

    piekey
    Participant
    Club Member

    Check to see if you are getting full throttle.

    Fit electronic ignition for better reliability.

    Fit a 3.9 diff.

    Just my quick thoughts, sorry if any have bern suggested before.

    #63868

    JAN
    Participant

    Fit a 3.9 diff? Firstly, if this is a 997cc car, that would be very over-geared. But more to the point, there is a problem: my Prefect has a 4.429:1 diff and will easily exceed  70 mph. The answer is to find the problem, and as Ken has said, if it was alright before the exhaust was fitted, that’s the first place to look.

    #63872

    scott brockbank
    Participant
    Club Member

    Thanks. I will.

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