News

wet plugs

Discussion in '308/328' started by johnvwatts, Feb 24, 2010.

  1. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    My 308 GTB (carb) repeatedly wets its plugs up with fuel on both banks at start up which makes it run bad. Not all the plugs just 1,2,3,8 possibly 6 - the others seam ok but are very dark but not wet. I have changed the extenders and plugs but still have the problem . Could this be a coil problem or maybe a fuel pump pressure - its running original coils and pump.
     
  2. To remove this ad click here.

  3. Ferraripilot

    Ferraripilot F1 World Champ
    Project Master Owner

    May 10, 2006
    16,218
    Atlanta
    Full Name:
    It's man
    Might want to check the points. How is the engine running once fully warm in in the higher rpms?
     
  4. Steve King

    Steve King F1 Rookie

    Feb 15, 2001
    4,366
    NY
    John need just a little more info. Like are you running points , how good are your wires , what heat range plugs are you using , when was the last time the carb's were tuned. Also is the distributor advancing as you increase engine speed. Are you using the choke or are the chokes open. Does the car run well after it has warmed up. Please give us a little more info. Thanks.
     
  5. BillyD

    BillyD Formula 3
    Silver Subscribed

    Feb 28, 2004
    1,675
    Pacific Northwest
    Full Name:
    Bill
    Could be a weak ignition system. I had to be very careful not to flood mine b4 I got rid of the points & went with electronic ignition & hotter coils. Night & day difference, haven't fouled a plug in a year.
     
  6. md88plt

    md88plt Karting
    BANNED

    Mar 4, 2008
    201
    usa
    Full Name:
    dc
    Billy D what type of ignition did you go with?
     
  7. To remove this ad click here.

  8. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    #6 johnvwatts, Feb 24, 2010
    Last edited: Feb 24, 2010
    The car is not running points but the original single distributor with twin magnetic pick ups. There are then two amplifiers for the twin original coils. Spark plug wires are new. Did try screwing in the carb adjust screws on the offending carbs but it seems to make no difference - fuel is still getting through and flooding. Car is running 50 idles and 130 mains. Seems to keep flooding throughout the rev range. Hav'nt driven as roads are salty since winter storage just though I'd run it up to temp in the garage and its running on 6/7 cylinders.

    Not using choke on start up and car still runs bad when warmed up ie problem doesn't clear and its driving me nuts!!!!

    Forgot to say car is euro dry sump.

    Just found another post in technical which says once fouled plugs need replacing and won't run properly again - ??

    Just remembered I had the same problem with a 78 GT4 which ran exactly the same ignition system. Only fitting an MSD system cured it but I don't really want to go to the expense of that here. It must be possible for the original system to function properly?
     
  9. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Could resist going into the garage to have another look even though its 11pm here. Decided to pull the distributor cap and all the terminals are green and corroded. There is also a brass ring in the middle which is broken in one place. All of which explains the problem I guess.
     
  10. Ferraripilot

    Ferraripilot F1 World Champ
    Project Master Owner

    May 10, 2006
    16,218
    Atlanta
    Full Name:
    It's man
    Good find. Clean the plugs and cap contacts and narrow the plug gap a bit further. I believe stock gap is .014-.020".
     
  11. BillyD

    BillyD Formula 3
    Silver Subscribed

    Feb 28, 2004
    1,675
    Pacific Northwest
    Full Name:
    Bill
    MD88PLT: I went with the 2 each Crane 3000 & Bosch red coils with both pickups in 1 dist.
    Bill
     
  12. To remove this ad click here.

  13. Ferraripilot

    Ferraripilot F1 World Champ
    Project Master Owner

    May 10, 2006
    16,218
    Atlanta
    Full Name:
    It's man


    I did something similar, but with Crane XR700s. I have the two triggers firing two Mallory 3RLi high energy inductive boxes which in-turn fire Bosch red coils. They provide quite a zap and require zero fiddling once set.
     
  14. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,280
    Houston, Texas
    Full Name:
    Bubba
    .025 is max gap.
    I use .022 on NGK BP5ES (relatively 'hot').

    Are you sure your carbs are leaking fuel down?

    I also have found little luck on cleaning fouled/shorted wet plugs to work again, I just toss 'em!

    Stock ignition on my cars....maybe MSD epoxy potted high vibration coils.
     
  15. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Big Tex, carbs could well be leaking down fuel as I just added some redex petrol cleaner additive stuff and this really helped the two troublesome plugs on cylinders 1 and 3. Cleaning the distributer cap helped but still kept getting these two plugs foul up. Also finally changed these two for new and it ran fine. As you say if the plugs foul up - toss them as they just don't seem to run right again.

    I just hope it starts up and runs ok nextime............
     
  16. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
    Full Name:
    Doug
    Are you running the extenders on the plugs? If so, fire the car up in the dark and see if there are fireflies in the plug holes. A cracked extender in virtually undetectable until you see it light up when running in the dark. They could cause misfires and eventually foul the plugs.
     
  17. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,280
    Houston, Texas
    Full Name:
    Bubba
    Even with my heat range I have really noticed troubles as the new fuel blends disolve years of varnish.

    A new set of plugs not very old always seems to have "one" that joins in late on the warm up.....hard to say.
     
  18. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Still no solution. Arghhhhhhhhh!!! Car is still running bad and now started backfiring/spitting out of carb on cylinders 1 and 2. Cylinders 1,2,3,4 now wet. Thought this might be an idnition problem so replaced both coils and mini amplifiers. No good.

    Car is off to mechanic tomorrow on trailer. He thinks it could be a cambelt issue - and I think he could be right - belt on cylinder 1-4 appears very tight and a crack sound can be heard when the engine is switched off. Belt on cylinder 5-8 is very loose but this bank is not wetting plugs. Could one of the tensioners have gone leading to a belt slip a tooth??
     
  19. Paul308GTSi

    Paul308GTSi Formula Junior

    Oct 26, 2008
    992
    Queensland Australia
    Full Name:
    Paul D
    ........can you get photos of the exact problem to post on here , , I'm sure a lot of guys would be interested in seeing and hearing what your mechanic has to say
     
  20. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Will do. Did a search and the plugs look just like those in the post "gt4 unbelievable backfire " although can't figure out howto highlight this post.

    Havedone compression test and all ok I think at 145/150 psi on cold engine.

    I notice that the gt4 car had the same type of magnetic pickup on the single dizzy. Whilst there does seem to be a cambelt issue, the problem does seem abit intermitant ie I have got the car running on 8 serval times with no fouling of plugs. Go back start it again and there is a problem .

    Will post what the Ferrari Specialist finds when it goes in.
     
  21. Paul308GTSi

    Paul308GTSi Formula Junior

    Oct 26, 2008
    992
    Queensland Australia
    Full Name:
    Paul D
    Hmmmmmmmmm, , if a camshaft was not in the correct position (and slipping a tooth is a big change) the fault would not be intermittent.

    I look for the real basic stuff , , , could it be a leaking gasket between the carbs and the head ?? To me thats the sort of thing that can be intermittent. Are there any vacuum hoses coming off any part of the carbs / inlets , , check them also , , it really sounds like an air leak.
    If the mixture of air and fuel is not rich enough it sometimes does not ignite, , the next firing stroke that unburnt fuel is combined with more , , then its too rich , , this is what makes intermittent faults.

    Maybe its just carby synchronisation , , , dead simple if you've ever owned and maintained a 4 cylinder bike.

    As for the cam belts they should have been set when installed.
    The belt is put in the right place , the tensioner is not locked , the tensioner roller is allowed to tension the belt and then it is locked in place. The spring on the tensioner is no longer doing any work , the whole thing is locked .... or should be.
     
  22. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Unbelievably I've just got it running on all 8 again. This is mad. Changed one coil lead (1-4) and touched the 1-4 distrib cam sensor but didn't change it. Put the old coil lead back on and it was still fine. So my guess is its an intermittant fault on the magnetic distributoe sensor for 1-4 bank. The 1-4 cambelt is way to tight though so must havebeen installed incorrrectly or can they tighten up? Anyhow I'm going to get it transported to the Ferrari Specialist to change the belts and see what he thinks.
     
  23. Paul308GTSi

    Paul308GTSi Formula Junior

    Oct 26, 2008
    992
    Queensland Australia
    Full Name:
    Paul D
    I have it !

    Your Ferrari is suffering an identity crisis !

    It seems to believe it is a Jaguar XJ 5.3 .......... my Jag went through all this wierd intermittent stuff all the time !
     
  24. Ferraripilot

    Ferraripilot F1 World Champ
    Project Master Owner

    May 10, 2006
    16,218
    Atlanta
    Full Name:
    It's man

    How can you tell it's too tight? Is the deflection that much different then that of the other belt?
     
  25. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
  26. johnvwatts

    johnvwatts Formula Junior

    Jul 7, 2007
    522
    England
    Full Name:
    John v watts
    Ok an update. Ferrari Specialist has sorted car and I pick it up on Thursday. Turns out cam timing was ok after all but three of the plugs had gone dead (due to the flooding I think), tappets were too tight and the small brass ring in the dizzy was loose, carbs and timing abit out.

    Strange thing is I changed the plugs and the flooding looks like it killed them also. So if you flood the car bad ie wet plugs as someone else said throw them and buy some more £10 for 8.
     
  27. tommott77

    tommott77 Formula Junior

    Feb 1, 2009
    652
    NC
    Full Name:
    Tom
    Thanks for the update. It is always nice to see issues resolved for future searches sake.
     
  28. bwassam

    bwassam Formula Junior

    Jan 3, 2005
    611
    North Bend, Oregon
    Full Name:
    Robert Wassam
    I had the same problem with a '77 308. I bought the cheapest plugs I could find, about a $1.50 each. I also changed wires and coils. Again I purchased the cheapest I could find. I figured that they would match and that is probably what Ferrari did back in the day. Now the car starts just fine, but it seems to run out of fuel at the higher RPM. Oh yeah, it is a points car.
     

Share This Page