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.

Lack of Power, fixed the problem

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by FWP, Feb 4, 2004.

  1. FWP

    FWP CRS

    Joined:
    Oct 11, 2000
    Posts:
    3,845
    Likes Received:
    3
    Location:
    Prescott Valley, AZ
    I thought this might help out others who may run into the same situation.

    Symptoms:
    No power
    Idles fine
    Won't hardly get above 3000 rpm, even at WOT.
    Doesn't miss
    Good vaccuum
    Good compression
    Good plugs/wires/cap/rotor
    Good fuel flow and pressure
    Timing is correct
    Carb is clean and working

    After all the stuff above was straightened out, that left me with a couple of options. Bad cam or plugged Cat. I had previously tested for the Cat using a vacuum gage- THAT DIDN'T WORK in my case, the vaccuum increased at 3000 rpm and was steady. So with my last 2 options being the cam or the cat, I went the easy route first, tested the cat.

    Here's how I did it.
    Drilled a hole in the exhaust right before the Cat, and tapped the hole to 1/8 NPT. I figured if the Cat tested good, I could put in a pipe plug and the exhaust would still be intact. Screwed in a 1/8 barb fitting, hooked a hose up and put a 0-15 psi gage on the other end. Started the truck up, at idle had about 1 PSI= good. Rev the engine up to 2000rpm, 10 PSI= BAD. Put her to 3000 and had a whopping 15 PSI= WAY WRONG. I'm suprised the motor ran at all. You should have less than 3-4 PSI at any rpm.

    Needless to say, the plugged up cat is in the trash. Man I love driving around with open headers /forums/images/graemlins/cool.gif

    I hope this helps somebody else out.
     
  2. Hossbaby50

    Hossbaby50 3/4 ton status

    Joined:
    Sep 1, 2001
    Posts:
    8,972
    Likes Received:
    0
    Location:
    Peoria, AZ
    why do you have cats? you don't need them in prescott.
     
  3. FWP

    FWP CRS

    Joined:
    Oct 11, 2000
    Posts:
    3,845
    Likes Received:
    3
    Location:
    Prescott Valley, AZ
    I needed the emissions when I lived in Albuquerque.
     
  4. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    Cool idea, brother!!! I'll have to file that one somewhere in my brain just in case I need it someday. /forums/images/graemlins/thumb.gif
     
  5. FWP

    FWP CRS

    Joined:
    Oct 11, 2000
    Posts:
    3,845
    Likes Received:
    3
    Location:
    Prescott Valley, AZ
    No sweat Paul /forums/images/graemlins/smile.gif I banged my head against the wall eliminating all the other stuff. It was frustrating not finding the problem /forums/images/graemlins/frown.gif til the last thing. Oh well, 5% rule /forums/images/graemlins/laugh.gif
     

Share This Page