1984 308 GTSI tach stops working and it only is running on one cylinder bank | FerrariChat
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1984 308 GTSI tach stops working and it only is running on one cylinder bank

Discussion in '308/328' started by fountain4ever, Sep 20, 2014.

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  1. fountain4ever

    fountain4ever Rookie

    Aug 28, 2014
    11
    Gilbert AZ
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    Tom Mischke
    #1 fountain4ever, Sep 20, 2014
    Last edited by a moderator: Sep 7, 2017
    We just bought a 1984 308 GTSI that is 100% original with 27K miles. It has been sitting since 2001 in a nice dry garage in Arizona. After extensive cleaning/replacing of the fuel pump/lines/hoses coolant and air hoses and a bunch of other stuff - The car runs again. I drove it for the first time last night - or attempted to. Running the car in the garage it runs very good. I took it out on the road and after about 1 mile - the tack stops and the can seems lethargic. I immediately sensed it was not running on all the cylinders. I made it back home and let it sit and cool down. I started it up again and tach worked and ran like original - hitting on all 8. I hear the pump buzzing. So I went again today to go around the block thinking it was a fluke. Same exact thing! Can someone give me some idea as to what is happening? Where should I look first? Is this a heat thing? I am looking for someone who has had this issue and might point me in the right direction. Thanks!

    Newbie Tom
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  2. hardtop

    hardtop F1 World Champ

    Jan 31, 2002
    11,294
    Colorado
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    Dave
    #2 hardtop, Sep 21, 2014
    QVs have an ECU for each bank. The tach runs off of one of them. It's been a long time since I owned one, so I don't remember which one but it's easy to trace. Your problem could be just a poor connection if you are lucky.

    Dave
     
  3. miketuason

    miketuason F1 World Champ
    Owner Silver Subscribed

    Feb 24, 2006
    15,811
    Cerritos, CA.
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    Mike
    #3 miketuason, Sep 21, 2014
    Last edited by a moderator: Sep 7, 2017
  4. stevel48

    stevel48 Formula 3

    Jan 4, 2005
    1,998
    Metrowest MA
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    Steve (85 308 Owner)
    #4 stevel48, Sep 21, 2014
    If you need to replace the MM spark boxes I recommend the ferrari service of Bedford updated ecu's that you can get from ricambi. The same thing happened on my 85 and I replaced them to sold the issue.
     
  5. Ccashen1

    Ccashen1 Rookie

    Jun 29, 2013
    18
    #5 Ccashen1, Sep 22, 2014
    Crank position sensor. I had the same thing happen to mine. Easy fix - or so my mechanic says. Good luck.
     
  6. Bobbytinvab

    Bobbytinvab Karting

    Jan 22, 2010
    237
    Virginia Beach, VA
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    Bob T
    #6 Bobbytinvab, Sep 22, 2014
    +1 on the crank sensors ... not a hard fix ... nice pic from Mike T shows their locations
     
  7. fountain4ever

    fountain4ever Rookie

    Aug 28, 2014
    11
    Gilbert AZ
    Full Name:
    Tom Mischke
    #7 fountain4ever, Sep 24, 2014
    Sorry have been busy with work and not much time to respond. I very much appreciate all the responses and the nice welcome. I bought 2 crank sensors and will try to get them installed soon... One at a time - I like to take small steps so I can see what actually works! :)
     
  8. fountain4ever

    fountain4ever Rookie

    Aug 28, 2014
    11
    Gilbert AZ
    Full Name:
    Tom Mischke
    #8 fountain4ever, Sep 24, 2014
    Last edited: Sep 24, 2014
    Steve - I was told the ECU's can be finicky and not to mess with them..... Do they sell new ones or rebuild the ones I have?

    I am sitting here going through some logic in my mind and appreciate any input as to my thoughts. Being the car seems to run fine when cold and running for the first 15 mins or so that would seem to me to indicate that the ECU's would be fine as they are not in the Engine compartment so heat would not really be a factor. I guess maybe they could get warm from the current running through them so I guess that shoots down that theory. I read a few days back that the Crank Position Sensors were the cause of this on other peoples cars and that they frequently fail and being mine are original - I bought two off ebay. They only had two but I know there are three. I figured I would replace one at a time and then test it after each one. One thing I thought I should try first is unplugging them and cleaning the connections to make sure they have good contact. It sounds like a number of people have all had a similar issue and it was the sensors. I am hoping that to be the case here. I am thinking the ECU's will not be quite as inexpensive of a fix. :)

    One thing that confuses me is that there is one sensor for each bank of cylinders and the 3rd sensor is for the tach. How is the tach and the one bank of cylinders connected? if one Sensor went out wouldn't it just affect the one and not both? It seems odd that both sensors would act up and the exact same time while driving. Just my random thoughts.... Anyone?
     
  9. fountain4ever

    fountain4ever Rookie

    Aug 28, 2014
    11
    Gilbert AZ
    Full Name:
    Tom Mischke
    #9 fountain4ever, Oct 22, 2014
    Update 10-22-2014 - I installed two of the three Crank sensors and drove the car. It did not act funny and ran fantastic! I think we have problem solved! Thank you all for your input and direction! Next we will install new tires and some minor cosmetics and then just enjoy her!
     
  10. GordonC

    GordonC F1 Rookie
    Owner Rossa Subscribed

    Aug 28, 2005
    4,163
    Calgary, AB, Canada
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    Gordon
    #10 GordonC, Oct 23, 2014
    Hi Tom, congrats on your 'new' Ferrari! I'm glad you solved that one problem, but I have to ask - you said the car was sitting since 2001, then you cleaned/replaced the mentioned items - when was the last time the timing belts were replaced? Did you replace the cam timing belts since you bought the car?

    If it was sitting since 2001, and you haven't replaced the timing belts, they're at least 13 years old. The majority consensus around here is that they should be replaced every 5 years, driven or not. Some say every 3 years, some push it to 7 or 8 years - but if yours are 13 years old, you absolutely should replace both timing belts, and tensioner pulleys, ASAP before doing much more driving, if any.

    Regards,
    Gordon
     
  11. stevel48

    stevel48 Formula 3

    Jan 4, 2005
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    Steve (85 308 Owner)
    #11 stevel48, Oct 23, 2014

    glad you fixed it. the boxes, they are new. they toss the old internals and put in new digital boards and reuse the case. when the the boxes go (and they will) you have two choices. a whole new ignition system or these FSOB boxes. i bought them right away because they probably wont be available forever and these are items that cannot be replaced except with used units.
     
  12. Hejman

    Hejman Rookie

    Mar 13, 2014
    10
    #12 Hejman, Nov 6, 2014
    I'm having a similar issue with my '85 QV. The front bank (5-8), and the tach sensors are relatively easy to get at. Anyone have any advice on getting to the last one, bank 1-4?
     
  13. Hejman

    Hejman Rookie

    Mar 13, 2014
    10
    #13 Hejman, Nov 6, 2014
    Never mind. I removed a few hoses and such first. With a little luck and the right tools I was able to get the last sensor in. However, my issue remains ...I'm still running on four cylinders, Argh! I crossed the plugs on the ECU's and bank 1-4 still remained off (only getting 1/2 power at idle and cold exhaust out the rt. pipes), so it's not the ECU. My cap and rotor looked brand new (replaced two years ago) when I pulled them off. I can smell gas at idle, so it's not the injection ...Does this just leave the coil?
     
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  14. ME308

    ME308 Formula 3

    Nov 5, 2003
    1,550
    Munich, Germany
    Full Name:
    Michael
    #14 ME308, Nov 7, 2014
    either coil and/or coil wire to distributor ...

    verify +12V at terminal 15 of the 1-4 cyl bank coil

    if o.k., swap coils and see what happens (hopefully front cyl bank 5-8 cuts out ;)
     
  15. hardtop

    hardtop F1 World Champ

    Jan 31, 2002
    11,294
    Colorado
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    Dave
    #15 hardtop, Nov 7, 2014
    If switching coils doesn't work, start looking at connections including the ECU connector. 308 connectors are somewhat less than, shall we say, top notch. Wiggle 'em, push on 'em, etc. See if anything happens.

    Dave
     

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