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Rough running Testarossa

Discussion in 'Boxers/TR/M' started by Andy T, Nov 11, 2004.

  1. Andy T

    Andy T Karting

    May 31, 2004
    56
    Sheffield - England
    Full Name:
    Andy
    My '91 21k mile Testarossa runs roughly on a light throttle opening up to 2,500 rpm. It seems 'snatchy' and there is a lot of shunt in the transmission. It runs ok when the throttle is opened wide, and at higher revs. I thought this may be a manifold airleak perhaps, but has anyone else experienced it and what are the other possibilities?

    TIA

    Andy
     
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  3. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,563
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    I just changed and Flushed my coolant system and have these exact symtoms. Everything was perfect before. What can it be?

    Please help !
     
  4. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    It could be many things....

    But first you need to check/set the butterfly gaps to be correct (.003"), and perfectly synchronise the throttle linkages to have balanced vacuum at idle and at small throttle.

    Then the mixtures need to be checked. A UK car is adjustable but US spec is different, so you need to consult your manuals.

    If the engine is balanced and tuned correctly (0.7-1.2 %CO at idle of 1000rpm), then it should be pretty smooth. The K Jet (very early) cars can surge/hunt a bit while warming up as the control pressure reg's get out of synch with each other, but the KE cars are much better.
     
  5. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    Ferrarifixer, I've noted the same problems with my BB512i since I got back from the FFQC...what do you suppose it is?
     
  6. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,563
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    Dear Andy,

    I posted this in the Tech section

    Shamile Shams Kassam II


    As y'all know, I'm chasing down some problems on my TR ever since I did a coolant change.

    If your TR has a jerky uneven push-pull feel when driving, it may feel like the transmission but (in my case ) was an engine miss. Most of us are used to what a miss feels like in a V 8. A flat 12 exhibits a very different feel.

    OK, the TIP of the day!

    If you are chasing a miss, check the cables going into the distributor cap. I know what you're thinking....it screws in, that's probably the best connection there. The way the cable is held is by a screw which is really a pin that pierces the wire and clamps the wire in the cap. ( screw is in each contact point of the distributor contact ) This connection is succeptible to burns in the wire at the pin and can create great resistance or complete loss of connection. I spoke to Magnicor when ordering a new set of wires and they said that the Ferrari Cap was an inferior design as it leads to burns and lack of connection. They said that even their wires were not immune to this problem.

    What I have found, leave a little excess wire so you can snip and reinstall if you find the resistance has gone up.

    I had a complete loss of contact on #6 and resistance in the M ohm range for #12 and #1. After snipping and reinstalling (the old wires ) I was able to get a fairly even resistance range for all my wires. My " OLD " wires were newly installed during a major service only 3 years & 10,000 miles ago. CHECK YOUR CONTACTS !

    Shamile

    Freeze...Miami Vice !
     
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  8. parkerfe

    parkerfe F1 World Champ

    Sep 4, 2001
    12,887
    Cumming, Georgia
    Full Name:
    Franklin E. Parker
    It turned out to be a vacuum leak causing my Boxer to surg while driving at a constant speed. It was a hose that had came lose on the intake plenum. I put the hose back on and no more surg.
     
  9. Testarossa1

    Testarossa1 Karting

    Jun 15, 2007
    229
    UK
    Full Name:
    Clive
    Hi Shamile

    After getting my car running again with help from this great forum:)

    I have had this exact issue you describe here-and want to get it sorted (my local indy has tried to diagnose it several times without success) they are now histiry after several sloppy incidents. Could you possibly post any photos of the dizzy work mentioned as I am a novice ( although gaining experince quickly-and lovin it!)

    Thankyou

    Best regards from across the pond :)


    Clive
    tr boy
     
  10. Melvok

    Melvok F1 World Champ
    Silver Subscribed Owner

    Jul 25, 2008
    13,202
    Amersfoort, Holland.
    Full Name:
    Mel
    Clive, did you also work on the coolant system ?

    Did you check the (blue) temp sensors ? Just unplug one by one and see if anything happens...
     
  11. JohnMH

    JohnMH Formula 3

    Jan 28, 2004
    1,067
    Dubai, UAE
    I had the bucking bronco 91 TR syndrome too. An easyish fix. One oxygen sensor was giving bad signal. Where the coolant drains from the right side head it can splash on the o2 sensor connections. Clean, dry and reattach. It clears out at higher rpm because the sensor signal goes off so far that the KE eventually disregards it and the car runs better. Mine cleared out at 3000 rpm with a sudden jolt. If you want to check if this is the issue:

    Get the car warm and drive it.

    Unplug both o2 sensors

    Repeat. Note any difference.

    On mine that cured the main shuddering issue, but it only was completely cured when I replaced the sensors.
     
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  13. Testarossa1

    Testarossa1 Karting

    Jun 15, 2007
    229
    UK
    Full Name:
    Clive
    #10 Testarossa1, Mar 21, 2011
    Last edited: Mar 21, 2011
    Hi Mel and John

    Thankyou for the fast replies
    Ok here goes!! Remember the most hands on up until last week was changing a fuse (shameful i know)
    Also my car is late euro KE jet Without lambda and CATS engine # F113B
    Forgot to mention sometimes it is worse when engine is hot

    1. No coolant work
    2. What and where are the blue sensors
    3. Where are the O2 sensors
    4. Approx cost of new O2 sensors

    Thankyou again fellas

    Clive
    tr boy
     
  14. Melvok

    Melvok F1 World Champ
    Silver Subscribed Owner

    Jul 25, 2008
    13,202
    Amersfoort, Holland.
    Full Name:
    Mel
    #11 Melvok, Mar 21, 2011
    Last edited by a moderator: Sep 7, 2017
    ?? Lambda = O 2 !

    So if you write: no lambdas, there should be no O2 sensors, am I right ?

    They vary in cost but right ones (count the cables) cost around $ 70 each imho .

    You can see the two O2 sensors here in the straight pipes.....
    Image Unavailable, Please Login
     
  15. Testarossa1

    Testarossa1 Karting

    Jun 15, 2007
    229
    UK
    Full Name:
    Clive
    Hi Mel

    Thankyou for the info-yold ya I was a novice!!
    So no O2 sensors to check how about the blue connectors you mentioned?

    Cheers buddy

    tr boy
     

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