1990 Testarossa stalling problem. | FerrariChat

1990 Testarossa stalling problem.

Discussion in 'Boxers/TR/M' started by DreamCarrera, Apr 11, 2008.

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

  1. DreamCarrera

    DreamCarrera Formula Junior

    Oct 25, 2006
    814
    S.E. PA
    Full Name:
    Eric
    My buddy’s 1990 Testarossa, which I got the chance to drive last night, has been experiencing a stalling problem. For example, if you are in third gear when approaching a stop sign and you depress the clutch pedal and use the brakes to stop the car the car stalls. Also, if you allow the RPMs to drop between shifts the car usually stalls. Sometimes the RPMs will drop below the idling point, to about 600-750 RPMs+/-, and then shoot up to 1,200 before recovering to the normal idle speed but usually the engine simply dies. Also noteworthy is that the headlights and dash lights, I drove the car at night, are dim for the first few minutes after starting(or restarting) the car. Even with the high beams on the headlights were very dim, however, after the car has been running for a few minutes the lights brighten to full power. It is very strange and happens each time the car is restarted, almost like clockwork. Other than this problem the car runs fine.

    Does anyone here have an idea as to the problem? My guess, because of the odd light symptom, is that it is an electrical problem.

    My friend experienced the same problem a few months ago after purchasing the car, but the problem was temporarily alleviated by the local Ferrari dealer when they replaced the battery.

    I would greatly appreciate any info. or advice you could share with me.

    Thanks,
    Eric
     
  2. KENCO

    KENCO Formula 3

    Nov 1, 2006
    2,396
    FL
    Full Name:
    KJG
    Maybe the TPS on the stalling issue.

    And the other, alternator. You would have to perform the correct tests on both to determine if these are at fault. If not keep searching.
     
  3. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,038
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Assuming that this is a US version TR, this post:

    http://ferrarichat.com/forum/showpost.php?p=136665456&postcount=4

    describes how to check and adjust the throttle microswitch (aka TPS).

    For the alternator, just measure the voltage across the battery at ~2K RPM after cold start-up and when warm -- should be low 13V minimum. (Again, assuming a US version TR, there is a larger electrical load during cold-running so that is more stressful on the alternator.)
     
  4. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,712
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    The dim lights sounds like your alt. is going out.

    The stalling is probably that your banks need to be balanced. I had the same exact stalling issue you have. I had my local F pimp re balance the engine...they also raised the idle a little.....car runs perfect.

    When you blip the throttle, the revs rise, fall and undershoot the idle point and stall out.

    The low idle and (perhaps) bad alt. doesn't produce enough power for the lights. I find, when you have a bad battery, it was because of the alt. or the bad battery starts killing the alt. Usually, if I have the severity of a dead battery, I rebuild the alt anyway.

    You could try and balance your engine, but after a few good bosch shops did it over the years....Ferrari ( F pimp ) did it the best with their balancer tool. The car has never run better or smoother.


    Shamile

    Freeze...Miami Vice !
     
  5. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,401
    Alabama (was Mich.)
    Full Name:
    Jeff
    I agree with Shamile about "balancing" your engine's fuel mixtures. This is the most common cause of surging, and varying idle speeds after throttle-back-off. And while I'm on the subject, Shamile...may I ask....what was the "f-pimps" balance tool used to tune your engine? I use a 4-gas analyzer and after about 3 or 4 dances with the mixture/air bypass/vacuum, I usually get it pretty good. But if there is a better way I'd love to hear about it.
     
  6. KENCO

    KENCO Formula 3

    Nov 1, 2006
    2,396
    FL
    Full Name:
    KJG
    I would like to hear that one too. I have used an analyzer in conjunction with a vacuum gauge setup. I find it to be tricky and I am never really happy with it on any of my cars, it seems as if I always need to tinker with it.
     
  7. carguy

    carguy F1 Rookie

    Oct 30, 2002
    3,401
    Alabama (was Mich.)
    Full Name:
    Jeff
    Before I try and "tune" the fuel mixture, I always install a fresh set of spark plugs, check the plug wires and dist. caps for continuity, check the auxilary air bypass valves, and verify that all vacuum hoses are okay. It's also a good idea to check all electrical connections. Any one of these items can throw off your readings. I feel the same as KENCO, it's a delicate balancing act to try and satisfy each parameter when tuning the fuel injection system. I also end up "tinkering" with the car every year or so to keep things "optimum". In the past I've tried all kinds of cheap, supposedly easier methods, for tuning (wide band O2s, etc.) but the only thing that has worked has been the very expensive 4-gas analyzer. But I must admit....over time that gadget has paid for itself many times over.
     
  8. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,712
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    Kenco, Carguy,

    I actually don't know what it looks like. On the bill it was stated in the description:

    " 39806 Engine banks were off balance. Inspected with Ferrari balancer tool. Set both engine to run evenly. Test drive vehicle and checked. Engine rpm is even."

    Next time I'm at the F pimp ( always need something :) ), I'll ask if I can take a picture of it or at least look at it and describe it.

    I will say, they really got the engine running well.....first time I felt I got some value from the money I spent. I've had Bosch-authorized (porsche) shops that know this type of fuel injection like the back of their hand and still could not get it perfect.

    I can pull into the garage and before I turn the engine off, I can sit there and feel no side to side, no minor vibration.....nothing.


    Shamile

    Freeze...Miami Vice !
     
  9. KENCO

    KENCO Formula 3

    Nov 1, 2006
    2,396
    FL
    Full Name:
    KJG
    I have the workshop manual and I think from memory its the same that I already use. It's a mercury stick like that used on motorcycle carbs. Basically just separate tubes hooked to each bank to show vacuum pull from each.
     
  10. DreamCarrera

    DreamCarrera Formula Junior

    Oct 25, 2006
    814
    S.E. PA
    Full Name:
    Eric
    Follow-up: (for reference purposes)

    There were two causes of the problems with my friends Testarossa.

    The first problem: There was a short within the radio which was an aftermarket system. The radio was disconnected and the electrical issues disappeared.

    The second problem: The fuel system needed to be rebalanced. The stalling issue was eliminated by the rebalancing.




    Thanks again for all of your help guys.
     
  11. Shamile

    Shamile F1 Veteran

    Dec 31, 2002
    6,712
    Lakeland FL
    Full Name:
    Shamile
    Dear Ferraristi,

    Yeah....I wonder who suggested that one? :D

    Glad to hear all is well.


    Shamile

    Freeze...Miami Vice !
     
  12. snakes

    snakes Rookie

    Jun 23, 2019
    12
    Full Name:
    david skinner
    This site is so great, I was experiencing a similar problem on my 89 Testarossa and now I know what to ask the dealer to do versus a bunch of poking around. Any reco on authorized Ferrari dealerships in the New Jersey area? I'm in Madison which is north New Jersey. Oh, and what was the cost of said balancing? Thanks.
     
  13. xplodee

    xplodee Formula 3

    Jan 3, 2017
    1,101
    Allentown, PA
    Full Name:
    Tim
    Bradan couchworks in Long island knows exactly what to do with a Testarossa and saved me tons of money when he worked on mine in spring. Call up and talk to dan.
     

Share This Page