Welcome to Club Hot Rod!  The premier site for everything to do with Hot Rod, Customs, Low Riders, Rat Rods, and more. 

  •  » Members from all over the US and the world!
  •  » Help from all over the world for your questions
  •  » Build logs for you and all members
  •  » Blogs
  •  » Image Gallery
  •  » Many thousands of members and hundreds of thousands of posts! 

YES! I want to register an account for free right now!  p.s.: For registered members this ad will NOT show

 

Thread: backfire after shut down
          
   
   

Reply To Thread
Results 1 to 8 of 8
  1. #1
    sbcfierogt is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    hopkintion
    Car Year, Make, Model: V8 fiero
    Posts
    13

    backfire after shut down

     



    hey guys iv just gotten my 327 sbc running after replacing the heads, cam and carb. Iv tuned it by ear as best i can and i have it running pretty good. There is a off idle stumble, but other than that it runs great until i shut it down then about 1-2 secounds later a loud backfire. i believe it is through the exhaust although there is a white smoke in the carb. where should i start looking?
    thanx john

  2. #2
    Dave Severson is offline CHR Member/Contributor Visit my Photo Gallery
    Join Date
    Jul 2003
    Location
    Madison
    Car Year, Make, Model: '67 Ranchero, '57 Chevy, '82 Camaro,
    Posts
    21,083

    Sounds like the butterfly's in the carb are not going completely shut....
    Yesterday is history, tomorrow is a mystery, Live for Today!
    Carroll Shelby

    Learning must be difficult for those who already know it all!!!!

  3. #3
    thesals's Avatar
    thesals is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2004
    Location
    san diego
    Car Year, Make, Model: 66 mustangFB, 69 econline Drag Van
    Posts
    1,527

    yup... check and see if you have your throttle screw adjusted open too much when you let off the throttle all the way the bottom butterflies should be shut, if they're not, then you're not even idleing on your idle circuit.... which means your timing is probably too far off as well, because you adjusted the throttle screw to get it to run with the timing you've got would be my guess
    just because your car is faster, doesn't mean i cant outdrive you... give me a curvy mountain road and i'll beat you any day

  4. #4
    sbcfierogt is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    hopkintion
    Car Year, Make, Model: V8 fiero
    Posts
    13

    hmm i did adjust with the idle screw to make it run with the timming i had. damn your good ill go look at that thanx.
    Last edited by sbcfierogt; 05-23-2007 at 04:44 PM.

  5. #5
    sbcfierogt is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    hopkintion
    Car Year, Make, Model: V8 fiero
    Posts
    13

    ok so all the advise you guys gave me is working im just having trouble getting it to idle now, but im getting closer. i had to move my distributer a gear back becouse i ran out of room turning it and found milky oil so im off to take the top end apart just hoping it is a simple gasket.

  6. #6
    thesals's Avatar
    thesals is offline CHR Member Visit my Photo Gallery
    Join Date
    Feb 2004
    Location
    san diego
    Car Year, Make, Model: 66 mustangFB, 69 econline Drag Van
    Posts
    1,527

    more than likely is.... check intake first before pulling heads.... intake gaskets are more likely the point of failure.... and yeah, you'll have to get that timing retarded a little, its probably advanced a bit since you had it in your off idle circuit
    just because your car is faster, doesn't mean i cant outdrive you... give me a curvy mountain road and i'll beat you any day

  7. #7
    sbcfierogt is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    hopkintion
    Car Year, Make, Model: V8 fiero
    Posts
    13

    yup pulled the intake manifold today and the gaskets are soaked. owell im learning as i go, i believe it is due to the fact that i got my heads milled slightly and didnt do anything to the manifold becouse i eye balled it and thought it was ok, guess not. so ill bring it to the machine shop after the weekend and see what they reccomend. thanx again for the info ill try to keep ya informed.
    john

  8. #8
    sbcfierogt is offline CHR Member Visit my Photo Gallery
    Join Date
    Oct 2004
    Location
    hopkintion
    Car Year, Make, Model: V8 fiero
    Posts
    13

    i used felpro gaskets the ones recomended by afr but i cant think of the amount i had milled out of the heads right now but i do remember the machine shop guy telling me that the intake might need to be milled. but ill try to find or think of the amount i had milled tommaro. sry for the grammer late party night post.

Reply To Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
Links monetized by VigLink