308 GT4 Pertronix -- no acceleration past 4000rpms | FerrariChat

308 GT4 Pertronix -- no acceleration past 4000rpms

Discussion in '308/328' started by sammyb, Aug 12, 2016.

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  1. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
    Full Name:
    Sam
    After tons of struggles, I got the 76 GT4 started and timed with the Ignitor II. Seemed to be just fine in the garage, but under load at more than 1/2 throttle or anything above 4K rpms, it feels like everything is misfiring. Just flutter with an occasional random full fire.

    Ignitor II is mounted to the rear dizzy with the front as the slave. New Flamethrower coils and coil wires. Timed to 7 degrees at idle...which is what it was with the points. Points still in the front dizzy, but not connected to the coil.

    I'm baffled!
     
  2. Arvid

    Arvid Formula Junior

    May 28, 2012
    668
    Norway
    Full Name:
    Arvid Andersson
    Do you know if you got the 3ohm or 1.5ohm Flamethrower ? Pertronix techs recommends 1.5ohm for high revving engines. A 3ohm coil will/could create misfire at higher rpm.
     
  3. kiwiokie

    kiwiokie Formula 3

    Aug 19, 2013
    1,539
    Tulsa, OK
    Full Name:
    John McDermott
    Have you cleaned and checked the mechanical advance is operating correctly?
     
  4. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    26,785
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    +1 for at least putting a timing light on it to verify if the advance mechanism is quasi-working. Another item to check/re-verify that can give that symptom is improper phasing of the dist rotor(s) to the dist cap(s).
     
  5. ColoradoTiger

    ColoradoTiger Formula Junior

    Jun 11, 2010
    607
    Colorado
    Full Name:
    Mark
    I had something similar and it turned out that my ignition map got corrupted somehow...maybe a bad ground or something but once I got the correct map loaded, everything was fine. Can you hook up a laptop?
     
  6. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
    Full Name:
    Sam
    The coils are PerTronix 45001 Flame-Thrower II 45,000 Volt 0.6 ohm Coils. My understanding is they are specifically designed for the Ignitor II ignition system.

    I can't hook up a laptop, as this is a stock Pertronix Ignitor II system for the 308s and the car was running fine (and assuming mechanical advance was working fine) on points.

    I checked rotor phasing on the rear coil, but not the front.
     
  7. Arvid

    Arvid Formula Junior

    May 28, 2012
    668
    Norway
    Full Name:
    Arvid Andersson
    You are absolutely correct. I was thinking of the Ignitor 1 and 40Kv coils.
     
  8. TTR

    TTR F1 Veteran
    Rossa Subscribed

    Mar 29, 2007
    5,889
    Riverside, CA
    Full Name:
    Timo
    Perhaps a moot point now, but based on the above statement, why switch ????
    Just curious.
     
  9. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
    Full Name:
    Sam
    It was hard to start and I was getting sporadic bangs out of the exhaust when the car was warm at idle -- like the spark might be weak and fuel was burning in the exhaust. As it turned out, one of the relatively new Red Coils had started arcing -- but I didn't figure that out until the Pertronix was installed, so it was at that time I installed the Flamethrower II coils.

    I'm thinking now that maybe I'll get rid of the spark plug extenders and go directly from the Taylor wires to the plugs to try to reduce the number of possibilities. (Now if I can just find the plug ends to screw back on!)

    I also sent a product support email to Pertronix to see what they come up with. If there's a chance that it's simply just a bad unit, I don't want to chase my tail for another six months.
     
  10. robertgarven

    robertgarven F1 Veteran
    Owner

    Feb 24, 2002
    5,294
    Ventura, California
    Full Name:
    Robert Garven
    I have 2 gt4s and they both scream with regular points. just my 2 cents.
     
  11. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
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    Sam
    Out of the dozens of cars I've owned in the recent past for which electronic ignition conversions were available, this is the first time I've actually done one. In all honesty, I'm regretting it, because I simply haven't driven my car in over a year now and I'm missing it. (Don't fret, y'all, I drove the 328 GTS 70-plus miles last weekend.)
     
  12. 4right

    4right F1 Rookie
    Rossa Subscribed

    I had Pertronix installed on my former 308 and the before and after difference was amazing. Faster starts, significant boost in power and a noticeable difference between the stock coils and the Flamethrower version. I would recommend that you stay the course and find a solution.
     
  13. Albert-LP

    Albert-LP F1 Veteran
    Owner Rossa Subscribed

    Sep 1, 2010
    8,169
    around Modena, Italy
    Full Name:
    Alberto Mantovani
    I don't know Petromix, but with the OEM coils and ignition a misfiring is usually due to: Ignition caps lack if insulation and mixture inside them, spark cables gone, fuel mixture too rich due to some cars tuning problems. Written in decreasing probability.

    Good luck

    Ciao
     
  14. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,367
    NY
    I owned my car for about 2 weeks when the points head came loose and ended up with a intermittent spark. I was driving and temporarily lost the front bank which ended up loading the cylinders with fuel and then reignited. Than BANG and it felt like I blew the muffler off. I towed it home and did the conversion. This was back in 2001 and had the dizzy rebuilt and converted by a guy named Don King in CA. I used Bosch blue coils which were recommended by Don and once installed never touched them again and I assume the new care taker who bought the car 2 years ago still has them in. 77 GTB and ran up to the red line without a sputter. Once you fix the problem you shouldn't have to touch it again.
     
  15. mike996

    mike996 F1 Veteran

    Jun 14, 2008
    6,871
    Full Name:
    Mike 996
    +1

    Never did I see any Dyno results that changing to E-ignition increased engine power over PROPERLY adjusted/operating points/mechanical advance. And engines turning far higher RPM than these Ferrari motors used points in the old days so that's no issue at all.

    Of course, E-ignitions don't require the annoying periodic maint/lubrication/point replacement so, in that regard, it's a far better system, especially for emissions. So I'm not suggesting that an E-system isn't a good thing BUT when you couple conversion problems like this with the relatively low mileage that most of these cars see...I don't think there's any benefit in replacing a properly-operating OEM system.
     
  16. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,259
    Black Forest Germany
    Full Name:
    Martin N.
    I'm scratching my head about how this would work.
    Doesn't the Ignitor II kit for dual distributor setups consist of two Ignitor modules. One for each distributor?

    Talking about those electronic ignitions in general. I fitted an Ignitor I on a simple 4-cyl Alfa distributor ten years ago. Never touched it since, besides an occasional drop of oil for the shaft and occasional cleaning of the cap.

    Never had a problem and I am amazed about the reliability.

    Reason was not, that I did expect any performance improvements. It was simply, because the parts quality of points got worse and worst.
    But the car actually starts easier and is running smoother. Even with the age old stock Bosch coil.
    Had a Flamethrower coil in the beginning, but it did last around 6 months, when suddenly the car refused to start.
    Then I dug out the old blue Bosch coil from my trash can and reinstalled it. Like said, no more problems since 2006.

    Best Regards
    Martin
     
  17. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,367
    NY
     
  18. Saabguy

    Saabguy Formula 3

    Mar 28, 2012
    1,785
    Shreveport, LA
    The rule of thumb should apply: 90 % of ignition problems are fuel problems and vice versa.
     
  19. Martin308GTB

    Martin308GTB F1 Rookie

    Jan 22, 2003
    4,259
    Black Forest Germany
    Full Name:
    Martin N.
     
  20. GavC

    GavC Formula Junior

    May 9, 2004
    492
    Lincolnshire, Englan
    Full Name:
    Gavin Culshaw
    I run Petronix, through a single dizzy, as mine is a single model uK spec. I had similar problems a year ago. I traced it down to a faulty regulator on the alternator overcharging on load, which blew the Pertronix. I have never had any other problems with this set up. Might be worth checking your getting around 12v max feed to the coils as you got through everything else. Keep up beat it's a great system once in correctly.
     
  21. kiwiokie

    kiwiokie Formula 3

    Aug 19, 2013
    1,539
    Tulsa, OK
    Full Name:
    John McDermott
    That reminds me, the previous owner's mechanic told me he had trouble with the Pertronix on my GT4 and it turned out to be resistance in the old wiring reducing voltage at the Pertronix to 8v. Running a new 12v line via a relay cured the problem.
     
  22. sammyb

    sammyb Formula 3

    Jun 23, 2006
    1,857
    Where wife tells me
    Full Name:
    Sam
    I had already thought about too little voltage to the system. I never thought about too much to the Pertronix system though due to an alternator issue. This is my next check.

    By the way -- mixture is pretty spot-on. And since I haven't driven it in a while, I soaked the jets in carb spray to un-gunk them.
     
  23. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,367
    NY
    Do we assume that you removed and rewired the ceramic resistors?
     
  24. The Kook Abides

    The Kook Abides F1 Rookie

    Jan 4, 2011
    3,459
    +1. Set up properly the work great
     
  25. scowman

    scowman F1 Rookie

    Mar 25, 2014
    2,550
    Scottsdale AZ
    Full Name:
    Stu Boogie
    Swap the pertronix to the other dizzy. Check if problem persists. I did that. Turns out one of my advance curves was horrible. Had it recurved by a local shop. You can swap in less than two hours I bet.
     

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