TR MONOSPECCHIO WITH IDLING PROBLEM | FerrariChat

TR MONOSPECCHIO WITH IDLING PROBLEM

Discussion in 'Boxers/TR/M' started by gian_marco, Aug 29, 2012.

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  1. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Dear ALL
    I need your help. My TR euro spec, with engine F113A, start from cold with no problem.
    When the water temp start rising, the idling gets rought, jump high and low and finally the engine dies.
    On th emove the engine is just fine but it can idle at all, and in town is a nightmare
    any idea?
    I tought to change the auxiliary air valves but I'd love to have your ideas and suggestion
    many thanks
    Marco
     
  2. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Please does anyone have an idea?
    thanks so much
     
  3. Philwozza

    Philwozza Formula 3

    Apr 23, 2009
    2,045
    Winchester UK
    Full Name:
    Phil Worrall
    #3 Philwozza, Sep 7, 2012
    Last edited by a moderator: Sep 7, 2017
    I think that you have an air leak on the inlet system somewhere. I would check that before anything else.
    The auxiliary air valves can be checked by squeezing the pipe that feeds from the valve to the engine inlets. I.E. you close the air valve manually. Do this when the engine is warm. If it makes no difference it is not the auxiliary valves IMO.

    Also there is a micro switch on the RHS throttle body. This sends a signal to the electronics to tell it that the throttle is at idle. In a QUIET garage with the engine off, move the throttle cable by hand (between the throttle bodies) slowly and listen for the slightest click from the micro switch. It should click just before the throttle hits the closed end stop.

    There are some photos below of the parts that need checking.

    I am sure that others will help out with other ideas zoo. Keep in touch with feedback. :)

    P
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  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    The (stock) F113A engine is K-Jet without Lambda so almost no electrical things to check or go wrong (which is a plus), but you have Warm-up Regulators (which is a minus ;)). Has your car been modified in any way for importation (you haven't given your location) -- i.e., did they add some sort of Lambda system?

    The AAVs should be fully closed when the engine is warm, so, as a test, you can just physically block (or pinch closed) the air lines that pass thru the AAVs (simulating a properly closed warm AAV) -- if there is no change = AAVs are not the trouble; if there is a change = bad AAV. Same thing applies to the VLVs (vacuum limiting valves) -- they should be fully closed at idle, so blocking the air that might pass thru them simulates a properly closed VLV at idle.

    Was the car running perfectly and this trouble just appeared suddenly, or was the car recently (mis)tweaked and it's never been OK since then?

    If you can't find anything obviously wrong (broken hose, etc.) and the AAVs and VLVs seem properly closed at idle, the next diagnostic check IMO would be to measure the various fuel pressures on both banks: regulated supply pressure, cold control pressure, and warm control pressure. (But, if your system has been modified, that adds other variables).
     
  5. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Hello Guys
    Many thanks for your suggestion
    I'm from Italy and my car is an european spec model with completely stock F113A engine
    Unfortunately I live very far from any ferrari dealer so I'm trying to solve the problem alone
    I've checked the AAV and it works perfectly, just like the wur.
    I've looked for any air leaking using a carb cleaning gas near every pipes or connection and no result
    The problem arose little by little and now I'm thinking the CO misture might be the problem
    I've just finished a trip to the Alps in an old 911SC with the k jetronic system, the car was stock and pefectly set up at ground level
    As soon as we reached 1000m above sea level the 911 started the same idling problem of my TR
    So I assume my TR is runnng too lean
    What do you think?
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    And what about the VLVs?
     
  7. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Sorry but I've to admit I've no idea where is the VLV :-(
    Could you briefly tell me where it is so that I can check it?

    PS: I've also checked the cold start injectors and they work fine with no leack at all

    PS2: I've just realized I was pretty rude with this forum. I've asked for help without a presentation. I'm a classic car collector from Italy, crazy for Ferrari (but I've to admit I also own some 911). I've the privilege to own a 308 carb model with the rare Bb colour scheme (red with the black lower part), a red 512 bb carb model, and a black TEstarossa single mirror. I'm not a treined mechanic but I try to do everything I can on my car alone, just too good to work on my pride and joy. thanks to all the member of this community, you are so much more helpfull and friendly compared to the tipical italian Ferrari owners

    PS3: please forget my poor engllish, I' do my best but it's getting worse and worse....
     
  8. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
  9. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    #9 Steve Magnusson, Sep 10, 2012
    Last edited: Sep 10, 2012
    The VLVs are not the easiest things to access on your F113A engine (since they are located under the intake plenums in front of the throttle bodies). There's one for each bank -- Items F as shown in the figure from your OM page 64:

    Image Unavailable, Please Login

    This is the description of their function from the TR WSM (where I've added some labels to the various ports on the device). Like the AAV, they let extra air into the engine under a certain condition (only under very high manifold vacuum during hard engine braking/deceleration), but they should be fully closed during normal warm idle. When you "blip" the throttle, you may be briefly activating them when vacuum level spikes up after the throttle plates are quickly closed -- so a faulty one could be sometimes not sealing and then sometimes sealing. When there is very high vacuum present on the small port #1 = the internal valve is open and air flows from port #2 to port #3 so extra air enter the engine (and "limits" the maximum vacuum level -- hence the name). When there is not a very high vacuum present on port #1 = the internal valve should be closed and no air flows from port #2 to port #3:

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  10. SOFTWAREGUY

    SOFTWAREGUY Karting

    Oct 20, 2004
    153
    I had a similar problem with my 1985 Euro TR.

    When I started the car, the RPM's would oscellate at idle.
    Sometimes it would settle down, other times, it would go higher and higher (1.5k to 500), and finally stall on the low side.
    I also could drive 100 miles just fine, then when I came to the exit, the rpms would drop well below 1000 and I would sometimes stall.

    I had the Warm up regulators rebuilt. (You can search the forum for the guy who does them, or PM me). It seemed to solve most of the problem. Then they did general tune-up things.

    I am not knowledgeable as a mechanic, can only share my experience.
     
  11. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Hello
    I've tried to disconnect the VLV from the intake manifold and the idle is now perfect
    Therefore I suspect my VLV is not properly working
    Problem is I cannot find anywhere, Bosch does not produce it anymore and also the majority of spare specialist don't stock it anymore
    Can it be rebuilt?

    PS: dear Steve, I think you got it right from the beginning, all my gratitude for this
     
  12. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    No, not really practical. Are you looking for F PN 117646 = Bosch 0280160138 (which is the correct VLV for a F113A euro TR) or F PN 115741 = Bosch 0280160111 (which is for a later F113B TR, but would probably work OK, and just has some extra bracketry)?

    I realize this will add expense for you because of your location, but both RicambiAmerica (www.ricambiamerica.com) and All Ferrari Parts (www.allferrariparts.com) here in the US show these as being available.
     
  13. 335s

    335s Formula Junior

    Jan 17, 2007
    870
    SF Bay Area
    Full Name:
    T. Monma
    since you have a boxer with carbs, and a carb 308, I know this will sond silly, but gret investment in a PAIR of fuel pressure guages, as they are really 2 six cyl engines in unison...despite all talk...treat as two sixes which must-MUST-be matched perfectly evenly...thus fuel pressure is important with NO lambda-this should be easy car to keep going for you with some basic guages and fittings. these other parts are almost NEVER bad, warm up regulators go bad on all cars , all the time, so you should ck this BEFORE spending hundreds of dollars on obscure parts which probably are ok....think carefully of valve function, think cause and effect...the odd valve STILL might be bad-but you should test baseline first-to be certain...
    ciao!
     
  14. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Hello Dear Friends
    During this WE I installed the new VLV
    Unfortunately very little changed, there is an improvement but I still have some stalling from time to time
    I've also tried to play with the CO and idle settings and now the situation is improved
    Only downside, if a want a stable idle, it must be set at 950rpm which sounds not so good to my hears
    With lower rpm the idle goes up and down constantly
    But what is really bothering me is that if I disconnect any of the small pipes attached to the inlet manyfolds, everything smooths a lot and the engine seem to run better
    Probably I'll have to start checking all the pressures.....
     
  15. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Why is this a problem? The nominal warm idle spec is 1000 RPM (although the pressures inside each itake manifold plenum needs to be equal).

    Sorry that you got misled on the VLV, but my suggestion was:

    "Same thing applies to the VLVs (vacuum limiting valves) -- they should be fully closed at idle, so blocking the air that might pass thru them simulates a properly closed VLV at idle."

    to see if it had an effect -- not just unplugging the vacuum input hose to see if that had an effect (but I should've pressed you harder on this point).
     
  16. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Steve
    first of all, no need to apologize at all
    you are helping me a lot, no question about that
    And I also know that it's difficult to help in such problem if you are far away
    Plus I believe it's much more likely I did not exain myself properly :)

    Coming back to the VLV, I did exactly what you suggested me and I do not regret I changed that item (by the way it costed me 70$ new,so no big deal)

    The problem got smaller thank to this
    What I meant in my last topic is:
    I changed the VLV and thing's improved

    But if I set the idle below 950rpm, as it's been since I've bought the car 5 years ago from a ferrari dealer, the engine goes up and down and finally stalls

    Now you tell me the idle perfect set up is 1000rpm, ok, I've to check in the workshop manual
    But why this problem does not occour if I disconnect any of the small pipes from the intake manifold?for example the one on the driver side which goes to the black box over the rear left wheel...
    This is my wonder......whith that pipe (or any other ones) disconnected, the idle at 9000rpm is perfect.....

    I hope I made myseld clear this time

    And again, thanks to everybody. It's great to have your help and your company
     
  17. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    BANNED Lifetime Rossa

    Jan 11, 2001
    26,822
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Thanks for the very kind words and the indulgence Marco.

    One comment that I'd make here is that I found my tach gauge reads high -- when it shows 1000 RPM, the true engine RPM is ~860 RPM (so; consequently, it shows ~1150 RPM when the engine is really at 1000 RPM). Doesn't mean that all TR tachs read high, but you might want to check this point (if you are relying on the tach gauge for determining engine RPM). I use the frequency function on my multimeter and measure the RPM sensor signal (the TR flywheel with 146 teeth, or 146 cycles/rev, spinning at 1000 RPM produces a signal of 2433 Hz). Alternative, some (digital) timing lights have a pretty good/accurate RPM function.

    If you unplug the vacuum hose going to the MicroPlex ignition ECU over the rear LH wheel, and doing that giving a smoother idle makes somewhat more sense. When you do that, not only are you letting a small amount of more air into the engine, but the idle timing will shift from 14 deg BTDC to 10 deg BTDC. I agree it is surprising that unplugging any other small vacuum hose would have such a seemingly large effect too, but, (if your tach reads high), you may be at a very low idle RPM so a little change makes a big effect. Opening the air bypass screws a little more should be identical to unplugging a vacuum hose, so upping the idle RPM to the nominal spec should provide the same benefit.
     
  18. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    Dear all
    I finally solved all the problems, tha car is running just fine
    After all your suggestion I was able to sort out everything
    It turned out that I had all the following problems at the same time:
    completely wrong CO set up
    a broken VLV
    trottle pedal linkage out of symmetry
    idle setting wrong

    Next step is injectors cleaning and a nice service :) but it now should be only normal maintenance

    Again many thanks for your suggestion and support
     
  19. Testarossa Lover

    Testarossa Lover F1 Rookie
    Owner

    Dec 31, 2006
    3,622
    Newport Beach, CA
    Full Name:
    Haig Barsamian
    Have you changed your injectors to brass Bosch or you still have the original injectors? I did change mine to Bosch few months ago and it was money well spent. Est. $35-45 each.
     
  20. Testarossa1

    Testarossa1 Karting

    Jun 15, 2007
    229
    UK
    Full Name:
    Clive
    Fantastic news Gian Marco !!

    This forum is such a fabulous bonus to Ferrari ownership-lots of generous and very knowledgeable owners give of their time and effort so others may benefit :)

    I am starting to perform checks and small "easy" jobs on my car -through the help of this forum. :) very satisfying !!

    Tr boy
     
  21. gian_marco

    gian_marco Karting

    Apr 30, 2008
    70
    Imola - Italy
    Full Name:
    gian marco
    As far as I know my injectors are still original
    That's why I'm planning to either clean them with an ultrasonic device or change them all
    Any suggestion?
    Differences between the original and the brass ones?if anyone has a pic it would help me to understand which one are now fitted in the car
     

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