350 sbc runs rough and blows smoke

Discussion in 'Engine Topic' started by Justin Berke, Jan 16, 2019.

  1. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    Messages:
    10,307
    Likes Received:
    448
    Joined:
    Nov 4, 2004
    Location:
    Ringgold, GA
    Put some rags under/along side of the carb and remove the float level sight plugs. Turn the electric fuel pump on, DO NOT crank the engine. Watch for gas flowing out of the sight plugs. Unless you have a switch under the hood, in easy reach, this is better done with a helper.
     
  2. Lowend

    Lowend Administrator. .a car, a man, a maraca. Staff Member Lifetime Gold Member

    Messages:
    14,968
    Likes Received:
    445
    Joined:
    Mar 25, 1999
    Location:
    San Jose, CA, USA
    Waiting on timing info....
     
  3. 1980RS

    1980RS Veteran Member

    Messages:
    3,269
    Likes Received:
    547
    Joined:
    Jun 17, 2006
    Location:
    MN
    I guess if this is a Quick Fuel carb, I would look to make sure it's not flooding. I had a friend who had one of their 850's and it ran bad and flooded all the time and finally go it fixed. I know I posted about it in another thread but it turned out to be a float hanging on the rear jet extensions, then after fixing that the darn thing flooded another time. I found the float was hanging inside to rear bowl on one of the corners. I replaced it with a Holley brass one and now it has been good since last spring. That is something to look for with Quick Fuels float bowls.
     
    Justin Berke likes this.
  4. Justin Berke

    Justin Berke New Member

    Messages:
    28
    Likes Received:
    2
    Joined:
    Jan 11, 2019
    Location:
    British Columbia
    Hmm I'll look into it
     
  5. 77 cruiser

    77 cruiser Veteran Member

    Messages:
    538
    Likes Received:
    24
    Joined:
    Nov 17, 2006
    Location:
    Frostbite Falls MN
    Me 2
     
  6. Justin Berke

    Justin Berke New Member

    Messages:
    28
    Likes Received:
    2
    Joined:
    Jan 11, 2019
    Location:
    British Columbia
    Update** timing is fine. Took at the spark plugs that I installed last week and there is already crud all of them from starting. I clean em up and put em back in. The car started up perfectly and idled for a solid minute before it died because I had the fuel pump off. Tried turning her over again with the fuel pump on and she still has the same problem. I'm putting new spark plug wires in soon but I'm thinking maybe I need a new fuel filter? She is running wayy to rich and wont idle unless I keep my foot on the throttle

    Thanks
     
  7. Bandit723

    Bandit723 Veteran Member

    Messages:
    3,148
    Likes Received:
    463
    Joined:
    Oct 1, 2016
    Location:
    Waupaca WI
    So did the engine run good at one point and then started running rich? I would open up your float bowl sight plugs and turn on your fuel pump and see if the carb is overflowing. I am only suggesting this as it seems like the engine runs as expected with the fuel pump turned off.
     
  8. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    Messages:
    10,307
    Likes Received:
    448
    Joined:
    Nov 4, 2004
    Location:
    Ringgold, GA
    A new fuel filter is not going to help that issue.

    Lowend and others are zeroing in on a timing issue. Timing is "fine" doesn't help diagnose your issue. To start with again - what is your base or initial and total timing, without vacuum advance? Hopefully your using vacuum advance, so is it connected to full time or ported vacuum on the carburetor?

    I'm with some others in leaning toward a carburetor issue because of how quickly you're fouling the plugs. You said the fuel was set for 7 psi. Is that set through a regulator or is that what the pump is supposed to be set for? If you need to know how to check float levels or check for a stuck float, let us know, someone will chime in. If you need help with reading and adjusting timing, we can help with that also.
     
  9. Bills69

    Bills69 Veteran Member

    Messages:
    107
    Likes Received:
    3
    Joined:
    May 28, 2018
    does the carb have a choke and is it operating correctly
     
  10. John Wright

    John Wright Veteran Member Lifetime Gold Member

    Messages:
    14,681
    Likes Received:
    208
    Joined:
    Aug 9, 2002
    Location:
    Rustburg, Va
    I had a Speed Demon carb (w/4 corner adjustments) years ago that I took out of the box and ran it. It ran great on start up and then about 3/4 of a mile out from my driveway it started flooding and ran rich. I limped it back home and it died on the carport. Took the carb back off and loosened the bowls to find that it was chunked full of aluminum cuttings from machining. A chip had found its way in the needle and seat and was hanging a float open....cleaned all of that out and it ran okay. But customer service told me that it was my fault and those chips were from my new fuel lines and filter...LOL
     
    Justin Berke and 1980RS like this.

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.