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4.9L fuel starvation. FACIT fuel pump failure?

Discussion in 'Maserati' started by 71Satisfaction, May 8, 2013.

  1. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    Here's a doct about the original CDI (green) output power compared to a modern one (purple), and to the upgraded one in Germany (blue).

    The box remains identical.

    100 on the green curve is the basxe and max. output reached by a prefect running condition original CDI.

    You can see the prower dramatically lowering.

    The upgraded box has got at 6.500 rpm more power than a modern one, end the power of the original at ... 2.750 !

    Now, I understand why my engine power output felt dramatically on the bank after 5.250.

    Tested on my car and approved. Image Unavailable, Please Login
     
  2. thecarnut

    thecarnut Formula 3

    Apr 22, 2006
    2,161
    Atlanta
    Full Name:
    The Car Nut
    Very interesting. What was used as the "modern one" .... MSD? I would have thought a modern MSD would be at least equivalent, if not better, than the Bosch CDI box, but perhaps that is not the case. Do you mind sharing the contact information of the company that did the Bosch CDI upgrade? I have an extra dead CDI box that I could have them upgrade.
    I usually carry an extra CDI box with me. On my last very long trip the only failure the Ghibli experienced was a bad CDI box; I converted to a standard coil to finish the trip.

    Ivan
     
  3. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    I should dig out my notes.

    If I remember well it's a more modern Bosch CDI w/ 8 pins (instead of 3 on the old original).

    His work is warranteed 2 years.
    Image Unavailable, Please Login
     
  4. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    Here's a summary of what he advised me :

    " The schematic is standard for all cars with 3-pin BOSCH CDI, no matter if Porsche , Maserati, Alfa, …


    The motorsport-coil may be a little different, but since it is a BOSCH Motorsport coil, you hardly will have any chance to get a second one.

    Perhaps it has a longer spark duration but weaker spark strength or it has a stronger spark with a shorter duration.


    Series spill means that the ignition energy is different from box to box. You may have a weak box or a strong box or something in between.


    The power at idle doesn´t matter and is limited to 130% on the modified box, because otherwise it could damage the system.

    The rest of your calculation is correct, but I can´t promise that this is enough energy!


    Overhauling and energy modification is 335 Euro (incl. tax and delivery to France).


    But keep in mind: As long as you don´t solve the problem with the fuel pumps a stronger ignition box won´t help in any way! "


    and


    " the B221… coil is a BOSCH Motorsport coil, which I have no clue what it is exactly.

    The 001 and 002 coils are electrically (nearly) identical , you may ask BOSCH why the had different article numbers for Porsche and Maserati/Ro-80.


    I can increase the ignition power 15-20%, but that doesn´t reach the energy of the 8 pin box at higher rpm.

    The increased power is enough for the 74-78 Porsche Turbos, but I can´t say if it is enough for your motor.


    See diagram from my homepage. Green is normal CDI, Blue is increased ignition power, Purple is 8-pin CDI

    !!! RPM is for 6-cyl-.Motor, multiply it by 0,75 for your 8 cylinder motor!! Diagram is normalized: 100% is maximum ignition energy of 3-pin CDI at 0 rpm.


    Please keep in mind that the 3-pin cdi boxes have a series spill of 15% (ignition energy) and that is the same with the boxes with increased power! "


    and


    "
    The 3-pin BOSCH cdi-boxes are all the same on Porsche 911, Alfa Montreal and Maserati, even if they have different article numbers.

    The boxes can all go up to infinity rpm, but decrease ignition power, the higher the rpm goes. At about 6000 rpm (8-cyl), the power decreases rapidly, so depending on the motor you probably run into trouble. That is why the Alfa uses 2 boxes, one for each bank of 4 cylinders.


    Correct coils are BOSCH 0221121001 without ballast, but don´t use the new coils with silver housing (made in Brazil, Batch 908). Only use historic coils.

    As an alternative you can use BERU ZS-109 (without ballast).


    Solution:

    Fix the problems with the pumps and the coils, then see if the car runs fine at more than 6000 rpm.

    If not, use 8-pin ignition boxes from Ro80 or Audi 100 (0227200005, 0227200006, 0227200007). They have more power, even up to 7500 rpm (8-cyl.) "
     
  5. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    Even if I have a Special Factory engine, I did not estore my car for acing purposes.

    I'm not a Cazy Pilot as was her 1st Owner !

    So, I decided to stay aesthetically conform, then no 8 pins box possible.
     
  6. staatsof

    staatsof Five Time F1 World Champ
    Silver Subscribed

    Mar 13, 2005
    55,367
    Fuggetaboutitland
    Full Name:
    Bob
    Pertronix. Done! You can hide/disguise that one very well. My single distributor dual coils Espada originally had no electronic ignition at all. But it did have 4 sets of points in the distributor! :eek:

    I no longer need the capacitors or resistors yet they are bolted in place and for all the world look functional. The sensors are permanently properly aligned and there's no need for any points. Of course everything can be put back but with that dizzy (Marelli) it's the advance mechanism that I'd like to eliminate. But that requires far too many large MSD boxes at this point. Fortunately mine was in great shape when I had a friend align the sensors on a mounting plate that bolts into the dizzy. I'am also using a Jag rotor & cap from the XJS that got the Marelli distributoir and that's 25% of the price of a NOS Lamborghini Marelli original rotor & cap. Outwardly everything is indistinguishable until you really start to dig deeply. This car is a driver and while I own it is never going to become a concours going car. The difference in starting and performance with the Pertronix in place is really quite astounding when compared to the original coil, resistor, capacitor and dual points for each six cylinders.

    OTOH for my late Bora that particular Bosch box, which is nicely located outside of the engine compartment , has been flawless. Should it ever fail I think I'd just put some other guts in it. Maybe even the Pertronix which would actually be in the dizzy!
     
  7. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    As regards the advance mechanism, I noticed it can change the characteristics of the engine.

    You can get a more rageous engine in high recs but with many noises at the exhaust, flames out of it... and not so nice at low revs.

    Any opinion Bob pls ?
     
  8. staatsof

    staatsof Five Time F1 World Champ
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    Mar 13, 2005
    55,367
    Fuggetaboutitland
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    Bob
    For this old engine I stick with the stock OEM advance curve. Some US spec cars had an advance curve meant to reduce emissions and some also had a vacuum retard mechanism with a micro switch operated by one of the carbs. Other than getting them back to original European specification I don't play around with this. Experimentation mistakes are just too expensive for these engines. This topic has been discussed on here before so using search will help out.

    There are specialists who can make your distributor 100% healthy and set the advance curve properly. For other cars using those Marelli distributors the vendors I have spoken with tell me it's very hard to set that mechanism up properly and have it stay that way.

    As you know, the earlier Maserati GT cars with the V8 had a switch so that you could bypass the Bosch box and run strictly on the points. Ivan referenced it. IMHO that's not exactly a strong endorsement for the reliability of that particular Bosch box. Though it does reduce the electrical load on the points themselves. Still, the whole points mechanism is subject to wear and a reluctor or optical based unit just seems the best route to me. My Bora doesn't have a switch to bypass it's later style box because there are not points and that box has been solidly reliable for me through all kinds of long trips . Build it right to begin with! My Bora did have a switch for dual fuel pumps from a single tank system! :eek: "Here's a what we gonna do cause we a know that the parts, they are gonna fail" :p foolish pumps. My Espada had neither of those options or switches for them so naturally we got stuck badly once! But when I looked at car's 4 sets of points and the multilayered SS bands acting as springs with some of them broken off and stuff flailing around in there I knew that one needed a big upgrade! LOL. My Bora is 8+ years newer than my Espada so the technology had changed.
     
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  9. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    Thank you very much fo your time and explanations, Bob !

    On my own, no switch for the box, and I will keep into the car a 2nd restored box and the n2nd (911RSR) coil !

    + 1 spare fuel tanks switch.

    I'm thinking about puttig a 2nd car in the trunk... Just in case !!!
     
  10. thecarnut

    thecarnut Formula 3

    Apr 22, 2006
    2,161
    Atlanta
    Full Name:
    The Car Nut
    I am thinking of replacing the dual mechanical points on the Ghibli with a single optical pickup unit. I can visually phase the points but without a distributor machine it is impossible to get them 100% accurate. In addition, over time I am sure normal wear gets the points out of phase, which means four cylinders are not firing when they should. I do want to keep the original Bosch box and coil as replacing those units would require too many modifications.

    Any suggestions of which pickup unit would neatly fit inside the distributor and would play well with the existing Bosch box and tachometer?

    Ivan
     
  11. staatsof

    staatsof Five Time F1 World Champ
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    Mar 13, 2005
    55,367
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    Bob
    Call Pertronix and ask them if they can verify that their system works with the Bosch box you have. It works with a lot of boxes out there. People do add MSD boxes for even hotter spark when they convert to Pertronix. Send your dizzy to a conversion specialist for proper alignment of the sensors regardless of which system you utilize. I was able to get mine close with a simple 9 volt battery and a VOM with the distributer sitting on the bench. Pertronix has directions on their website. In my case I was dealing with getting the two sets of six cylinders aligned perfectly as well the overall alignment which isn't as critical as long as your rotor is in the right position when the system fires. The dual point setup is meant to increase dwell by providing more charge time, as one set opens the other very quickly closes, quicker than the set that's just opened. With four sets of points you can imagine how much more difficult that is mechanically to get perfect.

    They have a kit for the Maserati V8.

    http://www.pertronix.com/catalogs/pdf/ptx/2018/Pertronix2018.pdf
     
  12. Candide

    Candide Formula 3

    Apr 6, 2017
    1,402
    Monaco
    Bob,

    Nomally, now, we have at 101% of the possibilities of all the original material.

    Fully restored and upgaded original box.

    Bosch Competition original coil tested and in perfect running cond.

    Colder spark plugs that are in XLNT cond. perfectly tuned too.

    At that point, the only thing that could be restrictive, could be the ignition wires that could have oldened.

    As I previously told, next step will be on the bank.

    But the carbs run pefectly.

    The car starts at the 1st attempt without choke.

    I always prefe complicating my life in the chase of perfection on the original thing than using modern stuff.

    Indeed, I hate easiness !
     

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