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HELP!!! Early 88 Testarossa Gremlin!!

Discussion in 'Boxers/TR/M' started by jmbarba76, Dec 27, 2019.

  1. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
    385
    New Jersey
    Full Name:
    Joe B
    I am hoping someone can help me. I have an early 88 Testarossa and the ignition cuts out on the 7 - 12 bank after warm up and under load.The car has had a fresh major service including ignition caps, rotors, plugs, filters,etc. The fuel system was also serviced along with pumps, fuel distributor, regulators. New O2 sensors installed as well. We borrowed a breakout box and checked all pin readouts against a known good car and they all seem to correct. We did find some bad grounds on the ECU ignition and final stage units which were repaired but didn't fix the problem. Has anybody run into anything like this? Maybe fuse box issue? Maybe something in the wiring harness that we are missing? Please help!!
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  2. Steve Magnusson

    Steve Magnusson F1 World Champ
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    Does the engine keep running (on just the 1-6 bank) after the 7-12 ignition stops working, or does the engine stop running a few seconds after the 7-12 ignition stops working?
     
  3. 302Tim

    302Tim Formula 3
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    Jul 2, 2011
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    Beautiful car Joe, love the color. When you say "the ignition cuts out on the 7 - 12 bank after warm up and under load" does that mean you have determined its not a fuel problem and isolated to ignition, or do you mean that (entire?) bank stops running (could be fuel or ignition)? Also, "after warm up and under load" do you mean once warmed up and ONLY under a load, or does it occur once warmed up and at idle and/or under a load? Also does it do this consistently or intermittently? You mention fuel pumps and fuel distributor--what servicing was done to those? If happening at idle, determine if you have ignition pulses on that bank; connect a timing light to each of the 7-12 spark plug wires and ensure you are getting ignition pulses. If that checks good then move to the fuel system. Once warmed up and not running on 7-12 shut the car off and jump the L.H. fuel pump to see if it is operating (engine off/key on; relay "T" energizes the L.H. fuel pump).

    I suspect you mean your symptoms are only occurring under a load...a little harder to diagnose. A quick check on the ignition side would be to swap coils and see if your problem moves with the coil. If fuel related could be an issue with the (new?) pump. I'm curious what was done to the fuel distributors. Could also be fuse panel related but I don't believe those gremlins normally occur only under a load.

    If you can provide a little more information on your symptoms I'm confident we can help you track it down.
     
  4. Rifledriver

    Rifledriver Two Time F1 World Champ

    Apr 29, 2004
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    Great colors.
     
  5. xplodee

    xplodee Formula Junior

    Jan 3, 2017
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    Tim
    How are cables? Do they ohm out? Like Tim said above, check spark with a timing light. Ignition system is easier to rule out then look into fuel.
     
  6. OptimusPrime

    OptimusPrime Karting

    May 10, 2011
    221
    Florida
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    Tom
    Nice car! I have a black with black leather 88.5 and had the same issue. After I verified it was not a fuel issue, I swapped the coils and the problem moved from 7-12 to 1-6 side so I purchased a new ignition coil, problem solved. My problem only showed up once the car was warm and I also had some intermittent backfiring that went away when I put in new coil. Sometimes when accelerating it would lack power and then suddenly kick in, must have been heat soaked intermittent coil issue.
     
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  7. xplodee

    xplodee Formula Junior

    Jan 3, 2017
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    same exact thing happened to mine. I have a thread with generic part numbers. I replaced both coils and modules for under $200
     
  8. Motob

    Motob Formula 3
    Professional Ferrari Technician

    Nov 11, 2003
    2,146
    Berkeley, CA
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    Brian Brown
    You can try swapping the ignition ECUs from side to side to see if the problem follows, and swap coils/final stage units side to side to see if the problem follows.
    Most of the intermittent/no spark issues that I have seen on TRs were due to bad final stage units/coils, as they are the part that has the most load on it.

    Brian Brown
    San Francisco Motorsports
     
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  9. JohnMH

    JohnMH Formula 3

    Jan 28, 2004
    1,018
    Dubai, UAE
    I had the exact same problem on my 91, swapping coils from side to side identified the issue in 20 minutes.
     
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  10. jgmblair

    jgmblair Formula Junior

    May 27, 2010
    471
    Winnipeg, MB Canada
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    Jeff Blair
    Hey Tim, any chance you could find your post and insert a link into this thread.
     
  11. xplodee

    xplodee Formula Junior

    Jan 3, 2017
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    Tim
  12. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
    385
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    Joe B
    Sorry for the late response guys, I appreciate the suggestions. Ok so as for the coils and ignition modules they were already swapped and we are still losing the 7-12 bank. The bank drops from 15 kv voltage to 5 kv voltage.


    Sent from my iPhone using FerrariChat
     
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  13. Steve Magnusson

    Steve Magnusson F1 World Champ
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    #13 Steve Magnusson, Dec 28, 2019
    Last edited: Dec 28, 2019
    Why is it never easy :(

    Have you measured the voltage on the yellow wires (terminal 15) of the 7-12 coil relative to ground? Does it stay +12V during both good running and bad running, or does it droop down during bad running?

    The +12V power to the coils comes from a common source, but are split on the fuse-relay panel and pass thru separate terminals in the y horizontal white connector -- so wouldn't hurt to unplug/inspect/reseat that y connector. Since these G (yellow) wires in the y connector are +12V key switched sources, they are often (wrongly IMO) used when adding other electronics so have a look for any added mods/splices there, too.

    (side note: 15KV sounds a little wimpy for an electronic ignition -- is this the voltage you are measuring to fire the spark plug air gap, or the maximum voltage that the system can deliver to a larger air gap? Can't say that I've ever seen a direct spec for this in the F literature.)
     
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  14. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
    385
    New Jersey
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    Joe B
    Hi Steve, first of all thank you for the suggestions. Unfortunately those wires have been checked already and seem to be fine. Terminal 15 reads 12v under both conditions. The white connector was also checked and seem fine as well. From what i understand the 15kv is normal for these older cars. It may have been somewhere between 15 & 20kv the last time it was checked but we also checked another running TR and it was very similar. Like I said before there were some grounding issues that were fixed and the connectors have been cleaned up and checked as we go and we are slowly making progress. The car now runs about 18 miles before it starts to act up where as before it would only run about 1 -2 miles before acting up. This car was sitting for quite a long time before the engine out services started so there may be some corrosion or bad connections in the wiring harness that we havent found yet. We ordered a few new connectors that we should have by the end this week that we'll try and get installed by next week. Wish us luck. Happy New Year!!!
     
  15. Steve Magnusson

    Steve Magnusson F1 World Champ
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    It sure seems like something "analog" in the 7-12 primary stuff/wiring since you report it does fire, but just weakly, during the bad running and being a sort of thermal-time-heats-up-to-failure. On the other side of the coil (terminal 1), the red wire at the coil should be switched by the power module from a good connection to an open connection to the black (ground) wire at the power module so you might check the black and red wires for good swagging to their respective terminals in the power module connector, and the black wire swagging/connection at the other end to the chassis.

    Do you have a copy of Diagnosis Sheet No. 1? Since you've got access to the 25-pin test box, it would allow you to verify (or condemn ;)) the MicroPlex ECU operation. If not, give a shout and I can put it up on DropBox.
     
  16. xplodee

    xplodee Formula Junior

    Jan 3, 2017
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    Tim
    Sorry if this has been answered but... is this the original fuse panel? I wonder if the issue is due to heat buildup somewhere within the fuse panel’s layers from excessive resistance and potentially resulting in a temporary open until things cool down?
     
  17. MisterT

    MisterT Karting

    Feb 2, 2011
    87
    Fleet, Hampshire, UK
    Full Name:
    Simon Taylor
    i was going to suggest checking the fuse panel too. I lost a bank last year, had to made a small repair on fuse panel connector. I also cleaned up the whole panel and all connections. Now the car starts better and windows rise faster and I guess it must be running better too.
     
  18. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
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    Joe B
    It is the original fuse box. We are in the process now of checking all of the connections and cleaning them up as we go. I will update as soon as we find the culprit.
     
  19. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
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    Joe B
    Im sorry if I havent responded to everyone. I am reading all of the suggestions and trying to rule them out as we go. I promise I will update everyone as to what we find when we find it. Again, thank you all for the comments and suggestions.
     
  20. theunissenguido

    theunissenguido Formula 3
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    Jan 21, 2004
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    Guido
    Joe, dont use sprays for electronics, WD40 or other chemicals on the plastic layers of your OEM fusebox. It will destroy them in time and no repair will be possible.
    Guido
     
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  21. jmbarba76

    jmbarba76 Formula Junior

    Sep 12, 2009
    385
    New Jersey
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    Joe B
    Thanks for the tip Guido!!
     
  22. Newman

    Newman F1 World Champ
    Professional Ferrari Technician Owner Consultant

    Dec 26, 2001
    13,175
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    Newman
    I had the same problem with my low kms 89 and it was the EHA. The car would run great until warm then a power drop like flicking a switch and an idle that burbled. Keep in mind if the EHA was tested on the bench at room temperature it would pass the test.
     
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  23. tommydogs

    tommydogs Karting

    Nov 9, 2016
    133
    Los Angeles, CA
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    Tommy Robinson
    Had a problem with similar symptoms when I got my 1988.5 TR. After full engine out service it would die (7-12 bank) after some minutes running. Electronic readings were really funny. Started strong from cold every single time. Turned out to be hairline fracture in round connector to ECU above rear passenger wheel where pins would ever so slightly pull out as the engine warmed up or vibrated. Replace both 24 and 9-pin round connectors to both ECU boxes and haven't had the problem since.
     
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  24. MOSS

    MOSS Formula 3
    Rossa Subscribed Owner

    Apr 28, 2004
    1,211
    Hey Steve, concerning electronics, do you remember who on this board put electronic power steering on their TR?
     
  25. Steve Magnusson

    Steve Magnusson F1 World Champ
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    #25 Steve Magnusson, Jan 27, 2020
    Last edited: Jan 27, 2020

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