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carb popping?

Discussion in 'The Hokey Ass Message Board' started by niceguyede, Jul 28, 2011.

  1. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    I've been working on a 63 bel air that I picked up for my girlfriend. It is clean and in decent shape with the 283 2 barrel and 3 ott. I've got it running but I'm having some problems with it popping through the carb when I try to drive it. Here's what Ive done lifted from the bel thread:

    After rebuilding the carb and changing the plugs out the Bel starts. We ran a bunch of seafoam though it and it helped a lot. It idles super smooth. Now it's popping through the carb under load though. I tightened the exhaust and intake manifolds and double checked the carb. It all seems to be good. I know I still need to put a timing light on it and check that, but it idles too smooth to be too far off. I put new cap, rotor, points, condensor, and coil. I ordered new plug wires which will be in tommorrow, as well as intake gaskets, exhaust gaskets and doughnuts. I know I need to pull the valve covers and adjust the rockers. Any suggestions on what else to check? <!-- / message -->
     
  2. Sounds like you are on the right path of elimination.
    When you check your timing you will get a better idea.
    Could be the timing is off or worse the timing chain is stretched.
     
  3.  
  4. Russco
    Joined: Nov 27, 2005
    Posts: 4,327

    Russco
    Member
    from Central IL

    Sticky valve/bad cam lobe
     

  5. redo32
    Joined: Jul 16, 2008
    Posts: 2,137

    redo32
    Member

    OK I give!! what the heck is "seafoam"?
     
  6. burnin53
    Joined: Mar 22, 2009
    Posts: 597

    burnin53
    Member
    from cuba,n.y.

    Check your valve lash like you mentioned.
    Then start it without the valve covers on and see if the rockers are all moving the same.
    It sounds like a bad exhaust lobe on the cam to me.
     
  7. HEATHEN
    Joined: Nov 22, 2005
    Posts: 8,552

    HEATHEN
    Member
    from SIDNEY, NY

    Could be. Nowhere near as prevalent on the '60s sbcs as on '80s 305s, but I've still torn down a few 283/327s over the years and saw a lobe or two that was only half there.
     
  8. mikeey rat
    Joined: Aug 10, 2010
    Posts: 169

    mikeey rat
    Member
    from Australia

    vacuume advance diaphram maybe?
     
  9. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,418

    Von Rigg Fink
    Member
    from Garage

    or lean condition off idle?

    or vac leak
     
  10. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    I changed the water pump and was going to do the timing cover just to check the chain, but I got lazy. Im thinking it might be a valve as well. I'm just hoping it's not a cam lobe because I don't want to get that far into the motor unless Im going through the whole thing. Shitty part is my daily just took a dump and I need this up and running soon!!
     
  11. BLAKE
    Joined: Aug 10, 2002
    Posts: 2,783

    BLAKE
    Member

    Like PORKNBEANER says... start simple. I'd look for timing advance issues first if it starts and idles but coughs under load.
     
  12. Rickybop
    Joined: May 23, 2008
    Posts: 9,605

    Rickybop
    ALLIANCE MEMBER

    I agree with a bad cam.

    If it's popping pretty badly on acceleration, it's almost for sure a bad cam-lobe...or very likely more than one. Pull the valve-covers, and I bet you'll see that one or more of the rockers aren't moving nearly as much as the others.

    It's not so hard to change a cam and lifters. If you do determine it's a wiped cam, get as much of the metal shavings out of the engine as you can. Good luck.
     
  13. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    Gonna try that this weekend!

    Nope, pulled off the line and plugged it with same results

    No vac leaks, but I printed out 8 pages of carb service and adjustments I'm also going through this weekend. I was hoping not as many bad cam responces would come up as did, cause thats what Im thinking worst case is.
    I guess if Im gonna have to change the cam its gonna be something with a little more thump, and I'll have to throw the double humps on there, and the 4 barrel intake and 650 demon, and..............see why I'm hoping its simple!!!
     
  14. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,418

    Von Rigg Fink
    Member
    from Garage

    chunk of shit in your high speed jet?

    or the accel pump squirter?

    i see you said you rebuilt the carb..but did you clean out all the jets and passages?

    if so..than I'll shut up:D
     
  15. burnin53
    Joined: Mar 22, 2009
    Posts: 597

    burnin53
    Member
    from cuba,n.y.

    I've only rounded off 2 cams in 25 plus years of driving,and both happened right after most of the zinc was taken from most motor oil.
    I've heard people try to say this doesn't normally occur except during break-in,which I feel is untrue.
    Both of these cams were fully broken in before the zinc fiasco.
    I'm gonna run roller cams from now on.:D
     
  16. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    I hope I got it clean, I spent 4 hours cleaning and 15 minutes putting it back together! It went together so fast and easy I took it apart and did it again just to make sure I did'nt miss anything!
     
    Last edited: Jul 28, 2011
  17. Von Rigg Fink
    Joined: Jun 11, 2007
    Posts: 13,418

    Von Rigg Fink
    Member
    from Garage


    well than..

    must be somethin else

    My 235 with a single BBl carb would do exactly this when it sucked some shit out of the tank..I could clean it out where ever I was and go on from there til it happened again..than i cleaned the tank.

    probably an intake valve not seating, or burned..is it random? or steady? (the popping)
     
    Last edited: Jul 28, 2011
  18. 53sled
    Joined: Jul 5, 2005
    Posts: 5,817

    53sled
    Member
    from KCMO

  19. handyandy289
    Joined: Sep 19, 2010
    Posts: 354

    handyandy289
    Member
    from Georgia

    Do a compression test. A burned valve can cause the symptoms that you described.
     
  20. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    It will idle smooth after warm up, you can rev it up with no problems. Its only when its in gear under load that it pops and then its steady poppin. Thats why Im thinkin its just valve sticking. Just not gonna know till I get done testin everything and go through it all.
    It has been sitting since 1980 and the original owner was prolly a depresion kid because it had the original plugs and 5 original wires with the production date printed on em! My grandparents were like that, only replace what really needs replacing!
     
  21. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    Also on the list for this weekend. My brother is coming over to help and he has a compression guage and a vac guage. I've got the timing light and old sun tach-dwell meter.
     
  22. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    After I change the oil again Im putting the ?zzpp? whatever its called crap in that replaces all the zinc they took out.
     
  23. niceguyede
    Joined: Jan 19, 2009
    Posts: 633

    niceguyede
    Member
    from dallas

    Thanks guys, I just wanted to make sure Im in the ball park. I'm a metal guy, not a mechanic! I'll find out this weekend.
     
  24. Johnny Gee
    Joined: Dec 3, 2009
    Posts: 12,600

    Johnny Gee
    Member
    from Downey, Ca

    Another vote for cam going flat. Sneezing and ticking is the clue.
     
  25. MBog
    Joined: May 2, 2006
    Posts: 556

    MBog
    Member

    Cam or at the very least valve train related...
     
  26. Commish
    Joined: Jan 9, 2010
    Posts: 379

    Commish
    Member
    from NW Ok

    If it is a very steady rapid popping it is probably intake valve related, if you are lucky it could be rocker arm, pushrod, or a pulled rocker stud, unlucky a cam lobe.
     
  27. hozem396
    Joined: May 4, 2011
    Posts: 287

    hozem396
    Member
    from ohio

    I second Russco. The exact same thing happened to me last week. The rocker came off the pushrod because I have a bad cam lobe.
     
  28. oldcarfart
    Joined: Apr 12, 2005
    Posts: 1,436

    oldcarfart
    Member

    I had a issue like this years ago, the wire from points to coil had worn thru insulation and idled great but under load the vaccuum plate would move and short out points, let up on gas and all OK, easy enough to check as sometimes the small crap eats you an ass.
     
  29. backroads
    Joined: Jan 28, 2009
    Posts: 65

    backroads
    Member

    maybe something you've already done and i missed reading through the posts but did you change out the points, if it even still has point haha. When ever my car ran like shit the first thing i always did was change the points. up until i wised up and got rid of them
     
  30. Snarl
    Joined: Feb 16, 2007
    Posts: 1,639

    Snarl
    Member

    Look for a broken valve spring.

    Have you put a vac gauge on it? is it steady, or bouncing all over the place?
     

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