Dismiss Notice

Welcome To CK5!

Registering is free and easy! Hope to see you on the forums soon.

Score a FREE t-shirt and membership sticker when you sign up for a Premium Membership and choose the recurring plan.

catalytic converter clogged?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Dunc03, Feb 3, 2003.

  1. Dunc03

    Dunc03 1/2 ton status

    Joined:
    May 20, 2001
    Posts:
    157
    Likes Received:
    0
    Location:
    Tyler,Texas
    I have a 86 blazer wiht what looks like it maybe the original cat on it. I have always had trouble with it running in colder weather. It would start fine, but if you tried to accelerate in 2nd or higher gears it would bog down until it got warmed up. This problem never happened when the weather was warm, even if I had just started the vehicle. I recnetly swap the original 305 for a crate 330 hp 350. WIth the addition of the new motor the problem got worse. It doesn't want to go up on high idle on its own. I assume this is becauses of the lope at idle. IF you start it and rev it manually for a second and then let off it kicks up on high idle fine. Also when you rev it manually it acts like there is a blockage in the exhuast and when it has blown it out the engine sounds and runs fine. Is this cause by the cat being blocked or defective in some way. Also does anyone know who makes/sells high performace cats. All I have found so far is dynomax and those things are kinda high. I figured I would at least compair some prices before I bought one. Besides that no one local carries Dynomax around my place. Thanks for the help.
     
  2. seslick77

    seslick77 1/2 ton status

    Joined:
    Jan 27, 2002
    Posts:
    220
    Likes Received:
    0
    Location:
    Colorado Springs, Colorado
    I'd say replace the cat. They're only good for 60K miles or so. Call Jeg's for a Catco universal cat. Comes in different legths(sp). Like $60 I think... Might have to do some creative piping for it to fit if you have the single exhaust, but not sure. I have em on my true duals, work great unless your running a little too rich... Mine looked like a nuclear reactor until I fixed the timing and carb. /forums/images/graemlins/rotfl.gif

    Sam
     
  3. thebigdaddyof2

    thebigdaddyof2 1/2 ton status

    Joined:
    Dec 28, 2000
    Posts:
    2,053
    Likes Received:
    0
    Location:
    St. Louis, Missouri
    Doesn't really sound like a plugged cat. Cats are either plugged or they're not. They're not temp sensitive. Check with Summit Racing for affordable, generic cats. They have 'em in all sizes.
     
  4. SkulzNBonz

    SkulzNBonz 1/2 ton status

    Joined:
    Feb 20, 2002
    Posts:
    4,522
    Likes Received:
    0
    Location:
    OKC, Oklahoma
    Are you running a carbuerator? Sounds a lot like an electric choke out of adjustment or in need of a rebuild.

    John
     
  5. Dunc03

    Dunc03 1/2 ton status

    Joined:
    May 20, 2001
    Posts:
    157
    Likes Received:
    0
    Location:
    Tyler,Texas
    I'm carbureted alright. I have a new quadrajet on it. THe choke could be the problem. I'm not really sure of how to adjust the choke on this thing. It is still set the way it came from the factory. Know that you mention it I does takea very long time to open fully. I drove home tonight about 10-15 miles and the stupid thing was still at like half choke and on high idle. IS there a way to set the choke so That it opens faster or slower. I know that hte choke is closing when cold like it is supposed to. THe truck fires right up whne you crank it, but it does not go up on high idle unless to rev it a little at first. It feels like the engine is having to struggle to blow out the exhaust. ANy ideas on hoeto fix it if it is something to do with the choke or carb. Thanks for the idea.
     

Share This Page