R10 Flat spot - Help!
  • Register
  • Help
Results 1 to 10 of 10
Like Tree4Likes
  • 3 Post By R8philSA
  • 1 Post By Sunroof

Thread: R10 Flat spot - Help!

  1. #1
    Fellow Frogger! Gordini Pervert's Avatar
    Join Date
    Mar 2012
    Location
    Perth
    Posts
    198

    Icon4 R10 Flat spot - Help!

    Hello fellow Reno nerds

    Advertisement


    So Im in the process of fixing up my car to sell and it has a problem - flat spot when pumping accelerator - and when under load - just konks out. I have to wind up the idle to make it idle!!

    Carby
    • Cleaned the F_U_C_K out of it with carby clean (took it off)
    • cleaned jets / bowl etc
    • set mixture screw by ear (when idling)
    • has a webber FYI


    Distributor
    • 2 degrees advanced set by timing light (although the manual said 0 degrees?) but checking it again - it seems well out - ?
    • new points - also has a gap of 20 thou on peak of cam
    • new condenser
    • new rotor button
    • new dizzy cap
    • Also has new plugs
    • new leads
    • has the right orientation for cap and timing order (lead arrangement) correct
    • also checked vacume advance - holds when I suck it


    So my question is WTF?? thanking you all in advance (pardon the pun)


  2. #2
    Fellow Frogger! Gordini Pervert's Avatar
    Join Date
    Mar 2012
    Location
    Perth
    Posts
    198

    Default

    Also check timing light on cylinder 4 or 1? Or doesn't matter?

  3. #3
    COL
    COL is offline
    A110 COL's Avatar
    Join Date
    Mar 2002
    Location
    Van Diemen's Land
    Posts
    4,072

    Default

    Quote Originally Posted by Gordini Pervert View Post
    Also check timing light on cylinder 4 or 1? Or doesn't matter?
    Number 1 which is at the fly wheel end of the motor.
    Regards Col

    1973 Renault R12 Station Wagon
    1976 Renault R12 Station Wagon
    2002 Renault Laguna V6
    1973 Alpine A110

    http://alpine-a110.weebly.com/

  4. #4
    Fellow Frogger! bingham driver's Avatar
    Join Date
    Jan 2011
    Location
    Myers Flat
    Posts
    182

    Default

    Sounds like massive air leak to me, & close that point gap down a bit while your at it.
    Once I thought I was wrong but, I was mistaken

  5. #5
    Fellow Frogger! R8philSA's Avatar
    Join Date
    Feb 2012
    Location
    Vista SA
    Posts
    986

    Default

    My bet is the Accelerator Pump delivery is either blocked or the Accelerator Pump diaphragm is worn out and can't deliver the amount of fuel needed to squirt down the primary throat of your carbie.

    Carburettors’ work on the principal that they supply fuel over a wide range of accelerator positions, trouble with this is when you accelerate quickly the flow rate can't keep up and that's why the Accelerator pump is placed in the primary throat; to give it the extra fuel it needs between quick accelerations.

    Take your air filter off, open the Choke butterfly’s at the top so you can now shine a torch down the primary throat of the Weber. Now move the accelerator linkage quickly to full open and as you do that you should see a direct jet of fuel squirt down the Primary throat.
    If you don’t see that fuel squirting down, then this confirms the Accelerator Pump delivery is faulty.

    Take the top of the carbie of, remove the accelerator pump delivery tube, try blowing it through, it only has a tiny hole in it so get a good breath up. If it's blocked, take a very fine piece if wire and push it up through the tiny hole in the end. Also now check that there is a small gasket under the Accelerator Pump delivery tube. This needs to be soft and a good seal when installed otherwise most of the fuel from the Accelerator pump will dribble around it and that will also cause your symptoms.

    If all that is clear and working, go to your Accelerator Pump diaphragm. Undo the 4 screws and remove the assembly, you will probably find the diaphragm collapsed over the years of faithful service. A good speed shop will have a replacement. Small square one will do the trick. I'm assuming you have a Weber 32DIR fitted or similar twin throat down draft.

    Hope this helps
    Cheers
    Phil
    PS: My Caravelle had the same problem, lack of use tends to clag up the inside of old carburettors due to the Aluminium castings trying to return to Aluminium oxide!! Additionally the old diaphragms’ eventually just stretch beyond their use by dates!
    Sunroof, J-man and HONG KONG PUGGY like this.

  6. #6
    1000+ Posts
    Join Date
    May 2005
    Location
    Boonah Qld
    Posts
    2,538

    Default

    Explained very well R8PhilSA. Some thing for the "how to do it" book.

    On my cars with Sierra engines I now use 2 degrees. Seems to work best. Perhaps because of modern fuels.
    HONG KONG PUGGY likes this.

  7. #7
    Fellow Frogger!
    Join Date
    Dec 2010
    Location
    Melbourne
    Posts
    225

    Default

    With a weber replacing the accelerator pump diaphragm will do the trick. as it sounds like its cactus.

  8. #8
    Too many posts! JohnW's Avatar
    Join Date
    Jul 2001
    Location
    Perth, WA, Australia
    Posts
    10,816

    Default

    Check dwell, air leaks and dynamic timing with a timing light to look at centrifugal and vacuum advance/retard. Talking to a fellow a few months ago from a carbie place, he reckoned 90% of the carbie problems brought to them were actually spark - distributor and timing.

    Agree re the accelerator pump diaphragm possibility.

    Blowing the F"""K out of it could of course have dislodged muck from a big passage into a small passage.... Gently, gently with carbies.....

    Good luck.
    JohnW

    Renault 4CV 1951
    Renault R8 1965
    Renault Scenic 2005 (wife's)
    Renault Scenic 2007 (mine)
    Renault Scenic 2006 (daughter's)
    CitroŽn CX Pallas 1980

    National Co-ordinator, Renault 4CV Register of Australia

  9. #9
    Fellow Frogger! Gordini Pervert's Avatar
    Join Date
    Mar 2012
    Location
    Perth
    Posts
    198

    Default

    Cheers guys much appreciated! =) Will suss it out on Saturday, well Geckoeng will, (coming over to pick up a G box and trouble shoot)

  10. #10
    Fellow Frogger! Gordini Pervert's Avatar
    Join Date
    Mar 2012
    Location
    Perth
    Posts
    198

    Default

    Here's the 10 Im fixing up to sell on... (want to start doing up an 8) PM me for an offer (just have to fix front brakes and wipers) Needs a bit of TLC but what a beast!

    R10 Flat spot - Help!-sams_10.jpg

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •