Bad Tune-Up? | FerrariChat

Bad Tune-Up?

Discussion in '206/246' started by raywong, Jan 15, 2007.

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  1. raywong

    raywong Formula Junior

    Aug 29, 2004
    673
    Hong Kong
    Full Name:
    Raymond
    I just got my car bad from a tune up, the result's very disappointing!
    When I first pick up the car, it idles very low(500rpm) before reaching operational temp(185f), it often stalls at traffic lights. Very embrassing!

    So he turned up the idling speed to 1300 rpm(@185f) so it won't stall at lower temp. But now if I let the temp go up slightly(195f), for example if I drove the car a bit harder on open road, or if I am stuck in slow moving traffic, the idling speed will become very high(1800rpm), and won't come down until I let it cool down to 185f. Also very embrassing at the traffic lights!

    My questions:
    1. The mechanic told me he used #4 plug as timing light reference point, but I remember Mr. John Corbani told me to use #3. Which one is right?

    2. The mechanic modified the crankcase vent system so now the crankcase
    gases escapes directly to the atmosphere, instead of recirculating back to the engine. Any ill effect?

    3. The mechanic put in Castro 10W40 oil instead of 20W50. Is it ok?
     
  2. DzusFast

    DzusFast Karting

    Aug 20, 2005
    82
    Tahoe/Reno
    Full Name:
    Elmer Fudd Gantry
    Sorry to hear that. Your idle most likely is a direct result of his carb adjustment. I'm sure some Dino owners here can familiarize you with the basics, but from my experience, it sounds like he may have adjusted the 'air bypass' screws', and the 'idle mixture' screws incorrectly.

    Another possibility is that the 'butterfly valves'(Throttle) are not closing ALL the way, or just not synch'd evenly; stuck ignition advance machanism, vacuum leak, I could continue on that slightly advanced timing can also create those symptoms in conjuction with poor carb adjustment.

    Common mistake by unfamiliar mechanics: Adjusting one thing to compensate for another. (Bad)

    The Crank vent to atmosphere I don't see his reasoning, someone else can comment, but Castro 10w40 for winter temps is fine, but there are better oils now.

    Hope this helps.
    signed,
    Ex-Ferrari mech.
     
  3. dm_n_stuff

    dm_n_stuff Four Time F1 World Champ
    Lifetime Rossa Owner

    Dec 10, 2003
    43,723
    26.806311,-81.755805
    Full Name:
    Dave M.
    Ray.

    Is your car a US or Euro Spec?

    As to the idle, if you don't have an idle advance, (At least in my experience with my car), it's going to idle a little low when it's cold.

    Until we fixed that on my car, 500 rpm was about where mine idled. I got VERY good at keeping a heel on the throttle when stopped to keep the revs up a touch while at idle.

    After a couple of minutes, the problem would go away.

    Fixed it permanently by repairing the idle advance on my US spec car. (Boy was that a *****y part to find.)

    Does sound like your tune up guy has his timing light up his ass. Does he have a working knowledge of Ferraris, or is he a general auto mechanic doing his best with your car.

    Dave M.
     
  4. John Corbani

    John Corbani Formula 3
    Honorary Owner

    May 5, 2005
    1,153
    Santa Barbara, CA
    Full Name:
    John Corbani
    That mechanic has never read the book and is a danger to himself and your car. Book says set idle at 750-850 rpm for Euro, 1000 rpm for US version. Timing is from #3, not #4. There is always some blow-by and oil vapor coming from crankcase. If airbox is still on, vent from oil separator should go to it. If not, vent down to below frame so that oil does not get all over things.

    Figure that timing and carbs are all fouled up and have someone else check everything. Setting of microswitch on second set of points (US) is not covered well in the books and adds to the confusion. Set timing and carbs on main set only. Then adjust idle setting if necessary to compensate for timing change when 2nd set of points kick in.

    I talked about carbs in Dino Saga 060716. Hope it helps. Let us know how things work out.

    John
     
  5. raywong

    raywong Formula Junior

    Aug 29, 2004
    673
    Hong Kong
    Full Name:
    Raymond
    Thanks for helping!
    I have a Euro model. We did try setting idle at 1000rpm, then turned off engine for 5 minutes, then restart, idle dropped down to 500rpm and stalled. It seem way too sensitive to engine temperature change.

    He said compression test shown the first and last cylinders leak a little, also there are some trace of oil in the water tank. Could this cause my idling problem?
     
  6. ferrarinyc

    ferrarinyc Karting

    Nov 5, 2005
    119
    NYC
    Full Name:
    Tony G
    Ray,
    where do you live? maybe some people here would know a more qualified mechanic to look at your dino.
     
  7. raywong

    raywong Formula Junior

    Aug 29, 2004
    673
    Hong Kong
    Full Name:
    Raymond
    I live in Hong Kong, very hard to find someone who knows how to fix vintage cars.
     
  8. John Corbani

    John Corbani Formula 3
    Honorary Owner

    May 5, 2005
    1,153
    Santa Barbara, CA
    Full Name:
    John Corbani
    Ray,
    My Dino has all US stuff gone just like Euros. Also got rid of the thermostatically controlled idle stop. I set idle at 1000-1100 rpm and everything is fine. Any lower and stalling is certain. Santa Barbara is no warmer and perhaps colder than Hong Kong. Just hit 28 F last night and car started and idled just fine this morning. Car is outside under a carport. Choke is disconnected too. Gets to high 90s F in the Summer and all is fine then too.

    Get another mechanic and take the book to him if he has never seen one. With what you said of the timing on #4, you need new help. God knows what else is fouled up. We can help with info if you get stuck. Was car this bad before you took it in for the tune-up?

    John
     
  9. raywong

    raywong Formula Junior

    Aug 29, 2004
    673
    Hong Kong
    Full Name:
    Raymond
    Idle was normal(1000rpm) this morning(18deg Celsius), but then became very high(2800rpm) after fully warm up. I dropped off the car to him imediately and gave him a CD including:

    Dino manual complete.pdf
    MUM_Dino246gt.pdf
    Tuning 40DCNF Carbs.pdf

    I hope he will take the time to read them, I told him to re-set the timming this time using plug #3, and follow the manual, but he said the technical data doesn't mean much to a car this old, and he can tune it by exprience and feel... I will keep you guys updated...Thanks!

    John> Since I already paid him, I will let him try again, and if he still can't do it I will bring it somewhere else.
    Dave> I never had the idle advance on my car, and it was fine before. Cold:800rpm, Warm:1000rpm.
     
  10. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    it sounds like you have more issues than a tune up will fix...

    have the engine checked for compression, leakage, hydrocarbons in coolant, valve clearances, camshaft condition, distributor function, points/dwell setting,..

    then you'll know if you have a tunable engine at least...

    failing that... I can possibly recommend you to a mechanic there... I occasionally sub contract to Modena M/sport (New Territory) owned by Wayne Shen... and they have a couple of good mechanics...no Dino experience I'd imagine, but thorough and knowledgable mechanics...

    it might be that they can help you... indirectly via me if you like...
     
  11. raywong

    raywong Formula Junior

    Aug 29, 2004
    673
    Hong Kong
    Full Name:
    Raymond
    Phil> I will let him try first, I might ask for your help if he still can't fix it. Thanks!
     

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