308GTBi Intermittently Won't Start | FerrariChat

308GTBi Intermittently Won't Start

Discussion in 'Technical Q&A' started by Ianc50, Sep 6, 2017.

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  1. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    Hi All,
    I've looked everywhere to find info on the issue I've encountered, but been unable to find anything that exactly matches; so here goes:
    I have a 1981 308GTBi, which I've owned for the last 6 years, never having any issues with starting. This year, I had the car serviced at a main dealer during which time they replaced the belts and cam seals. When the car was returned to me I drove it the same day and after I'd parked up for 5 mins it wouldn't start, I rang the dealer and they advised to leave it for 5 mins and try again; just in case!......... guess what? It started! I drove it for another 15 miles or so, returning home; whereupon I checked whether it would start, once back in the garage - it started no problem. Two weeks later I went to visit a friend and left the car outside his office for 2 hrs after which, it absolutely would not start! The main dealer came and picked it up to carry out checks in order to determine the issue. Their synopsis, having "checked everything" was "your engine is worn out!" They had carried out cylinder leakage checks and a borescope - 2 cyl's were down on pressure and there was some scoring on one of the bores. Now; I'm no numpty when it comes to engines and I can't reconcile in my mind how the symptoms I've seen above are the result of a worn engine. I'm thinking more along the lines of intermittent crank sensor op, but I wondered what you guys think?! Any experience or ideas?
     
  2. thorn

    thorn F1 Rookie
    Silver Subscribed

    Aug 7, 2012
    3,322
    Tallahassee, FL
    I think you need a new mechanic.

    The engine may be worn, but their diagnosis to the problem at hand seems suspect.
     
  3. 308 milano

    308 milano F1 Veteran

    Jan 15, 2007
    5,257
    Montana
    Full Name:
    Kim
    I think you may have a problem with your fuse blocks. Had the same symptoms with my 84 GTB. Purchased a set of Birdman fuse blocks for around $120 US, took less than an hour to install and never another starting problem.

    +1 agree with Thorn, I think your mechanic is looking for work at your expense.
     
  4. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    I agree! The engine probably is worn as it's done about 70,000 miles. I'm going to do my own leakage and bore scope checks to confirm. The disappointing thing is that this is a main dealer diagnosis and you'd think they would know better or have seen most issues at some point! ☹️
     
  5. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    Thanks; I'll look into the fuse block replacement then. I've read that they can be troublesome and mine still has its originals fitted. Did the symptoms on your have any temperature relationship or was it just random non-starting regardless?
     
  6. 308 milano

    308 milano F1 Veteran

    Jan 15, 2007
    5,257
    Montana
    Full Name:
    Kim
    #6 308 milano, Sep 8, 2017
    Last edited: Sep 8, 2017
    Yes, some days would go out into the garage and it would fire up first turn of the key. Go to start it half hour later, couldn't start after trying for 20 minutes. Come back later and it would fire right up.

    And 70,000 miles is nothing on these cars.
     
  7. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Could be, but you really need to determine "spark or fuel" first. When you have the trouble, try unplugging the safety switch and turn the key "on" = you should hear the fuel pump run. If the fuel pump runs, turn the key to "start" -- if it cranks, but won't fire = most likely no spark, but should confirm/deny with a timing light.

    If it does always start with the safety switch unplugged, but won't start with the safety switch plugged in -- try a different ...101 relay for the "relay for starting" (or something like that).
     
  8. Ferraripilot

    Ferraripilot F1 World Champ
    Owner Project Master

    May 10, 2006
    17,171
    Atlanta
    Full Name:
    John!
    #8 Ferraripilot, Sep 8, 2017
    Last edited: Sep 8, 2017
    Weak fuel pump. Just fixed this exact same issue with an old Alfa. Installed a fuel pressure checking system at first and it was just a touch low. New stronger fuel pump (Walbro 255lph would treat you fine) did the trick. If you have good and quick fuel pressure then check the ignition boxes while cranking (when it doesn't start) by unplugging a spark plug lead and installing an old spark plug and checking for spark.
     
  9. Mantinger

    Mantinger Karting

    Jul 30, 2004
    145
    Netherlands, Drenthe
    Full Name:
    H
    308i? I assume with K-jet?
    You mention no starts after warm up.
    Disconnect the cold start valve after some warm up and try to start then. Just pull off the blue connector on the inlet plenum.
     
  10. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    Thanks Steve, I just need the problem to reoccur- so far it's behaving! When you say safety switch, to what are you referring there?
     
  11. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    Hi Matinger, yes; 308i. I'm not yet convinced that it's completely temp related, although it does always start from cold. I'll try the cold start valve next time it does it though, thanks.
     
  12. Ianc50

    Ianc50 Rookie

    Sep 6, 2017
    6
    Thanks. Do you know what the fuel pressure should read? I can set up a gauge to check what's being delivered. Did you measure it at the pump?
     
  13. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    25,040
    30°30'40" N 97°35'41" W (Texas)
    Full Name:
    Steve Magnusson
    Try searching on "blue safety switch" -- many prior threads/posts with photos.
     

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