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.

Fuel Level & Performance

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by chiefKP, Mar 17, 2000.

  1. chiefKP

    chiefKP Registered Member

    Joined:
    Mar 17, 2000
    Posts:
    16
    Likes Received:
    0
    Location:
    Pyongtaek, Korea
    I'm puzzled...

    As the fuel level in the tank drops so does the engine performance. I get great smooth acceleration with a full gas tank. Then as more fuel is consumed the valves chatter and acceleration stinks.

    I have a 5.0 Liter stock engine with a stock four barrel Rochester carb. Nothing special installed under the hood.

    Any ideas?

    Thanks...
     
  2. Goose

    Goose 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,127
    Likes Received:
    1
    Location:
    South Central Kansas
    Wow, never heard of anything like that. My only thought would be to check your fuel cap. As fuel is used, it needs to be replaced with air by venting action from the outside. If your fuel cap is bad, maybe a vacuum is developing inside your tank causing a lean condition.
     
  3. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

    Joined:
    Feb 17, 2000
    Posts:
    7,385
    Likes Received:
    0
    Location:
    Atlanta
    In addition to a problem with the cap that was mentioned possibly a problem with the vapor recovery system. Maybe a vac line is in the wrong place or leaking.

    Diging it in the dirt with my K5's
    Grim-Reaper
     
  4. delta9blazer

    delta9blazer 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    1,646
    Likes Received:
    0
    Location:
    Northern California, over by 7-11
    crap in the tank being run through the engine?
    with a full tank, percentage of particulate matter is acceptable for your engine to operate.
    once the level of liquid drops, percenatge increases.

    probably only a half-cent's worth.

    <font color=purple>delta9blazer</font color=purple>
     
  5. Eagle86K5

    Eagle86K5 1/2 ton status

    Joined:
    Mar 5, 2000
    Posts:
    974
    Likes Received:
    0
    Location:
    Whitehouse, Ohio
    I think I would agree with the Delta9 gentleman and remove and clean the tank. If it sat for a while you could have gunk in the tank as well as on the pickup. When full it pulls from the "clean" top of the pickup....as the level is lowered you could be getting to the clogged portion of the pickup....worth a try just to know you got a clean tank and pickup...I did it as a preventative measure on my 86 and did find alot of trash. And it makes a difference on the milage. Just a few cents from me.... [​IMG]

    <font color=green>Eagle86K5[​IMG]

    <font color=red>Only guy I know that can get out of line in a one car funeral
     
  6. Corey-88K5

    Corey-88K5 1/2 ton status

    Joined:
    Feb 17, 2000
    Posts:
    720
    Likes Received:
    0
    Location:
    Home: Michigan, Stationed: Hill AFB (Home of Moab.
    Acutally this is the older model blazers way of screaming I NEED 45 MORE C.I.'s OF DISPLACEMENT

    Corey
    88K5
    ( Guess they just made 'em better in 88 ) Man, I'm starting to like that one liner!

    [​IMG]<font color=blue>Girls Like Guys In Bow Ties</font color=blue>
    <font color=red>http://www.geocities.com/corey_perez
     
  7. Can Can

    Can Can Pusher Man Staff Member Super Moderator

    Joined:
    Feb 17, 2000
    Posts:
    15,552
    Likes Received:
    136
    Location:
    Cochrane, Alberta, Canada
    The guys are probably right about the cap and the evaporation canister. First unplug your canister to carb line and check for liquid fuel in your canister.......it might have to be replaced if it's full. Another trick to let more air thru your venting gas cap is to drill a 1/4" hole right thru the cap. Just be cautious when taking hard turns right after you fill up...............
     

Share This Page