Page 1 of 2 12 LastLast
Results 1 to 10 of 16

Thread: Acceleration miss??

  1. #1

    Acceleration miss??

    Acceleration miss?? I have a 350 crate engine with an Edelbrock carb and intake. It has been changed over to a 4 speed. I drove my truck to work in the morning and it ran great. I got home and shut it off for a few minutes. Went back out and it started bucking pretty bad during acceleration. Once it gets past 3000 rpm's it smooths out. I checked the timing, replaced spark plugs and wires and cleaned the carb. It almost feels like a vacuum leak. I replaced the carb gasket and checked the only 2 vacuum lines on the engine. The distributor is an MSD performer (only a year old) I don't think the fuel pump is very old but its the only thing i haven't replaced. Just wondering if anyone had any ideas. Thanks in advance

  2. #2
    Knows their $hit 84_K5's Avatar
    Join Date
    Jul 2010
    Location
    Florida
    Posts
    919
    Sounds like the vacuum, timing or carb. It’s just started happening quick, so that points more to timing… once you are sure it’s correct…check the carb, make sure it’s clean.. needle and seats. Could be the accelerator pump …. You can change the notch on the accelerator pump to give it a larger fuel shot on quick throttle. I had a similar issue a while back… messed around with the accelerator pump and the needles … fixed it right up. Replace vacuum lines for the hell of it... cheap and easy. Guessing the fuel pump is ok since it is smooth at higher RPM.


    84 K5 - Newer front clip
    350/ 350 Turbo/ NP 205
    6in Skyjacker on 35in Goodyear MTR
    Everything pretty much new
    Hundreds of hours in time and thousands of dollars wasted....

    My build thread - http://www.chevyk5blazer.com/forums/...4-K5-money-pit

  3. #3
    Senior member paladin1176's Avatar
    Join Date
    Nov 2012
    Location
    Durham, NC
    Posts
    1,210
    It sounds like crud in the gas, either float bowl or in a filter. I once had part of a leaf in my float bowl that would settle during low flow and cause stumbling but float around when i stomped on it.
    Last edited by paladin1176; 01-29-2013 at 06:38 PM. Reason: can't spel

  4. #4
    Ill check out the Carb. Maybe ill try and soak it or clean it. What does the accelerator pump do? I only know the basics of carbs. Thanks for the advice. I usually over think simple problems.

  5. #5
    Knows their $hit 84_K5's Avatar
    Join Date
    Jul 2010
    Location
    Florida
    Posts
    919
    everything you ever wanted to know.. enjoy http://www.edelbrock.com/automotive_...ech_vids.shtml


    84 K5 - Newer front clip
    350/ 350 Turbo/ NP 205
    6in Skyjacker on 35in Goodyear MTR
    Everything pretty much new
    Hundreds of hours in time and thousands of dollars wasted....

    My build thread - http://www.chevyk5blazer.com/forums/...4-K5-money-pit

  6. #6
    Senior member muddyK5's Avatar
    Join Date
    Feb 2011
    Location
    Bomb shelter in Medford Oregon
    Posts
    1,083
    Sounds like the float is stuck, overflowing the bowl, and once you romp into it it uses the excess leaning it back out.

    Do you have a fuel filter on that thing?

  7. #7
    It didn't have one when i bought it. I put a little inline one right after the pump. When i dropped the tank it didn't look bad. There probably was trash in the line somewhere though. I'm going to pull the carb today and see if i can clean it up.

  8. #8
    Knows their $hit 84_K5's Avatar
    Join Date
    Jul 2010
    Location
    Florida
    Posts
    919
    change the fuel filter.. I forgot about that


    84 K5 - Newer front clip
    350/ 350 Turbo/ NP 205
    6in Skyjacker on 35in Goodyear MTR
    Everything pretty much new
    Hundreds of hours in time and thousands of dollars wasted....

    My build thread - http://www.chevyk5blazer.com/forums/...4-K5-money-pit

  9. #9
    Senior member rtull32's Avatar
    Join Date
    Aug 2012
    Location
    Midland Texas
    Posts
    2,122
    Quote Originally Posted by 84_K5 View Post
    change the fuel filter.. I forgot about that
    Yep I've had the same issue start with the fuel filter and go from there

    Sent from my DROIDX using Tapatalk 2

    1983 K5
    350/SM465/NP208
    3/4 Ton 10 Bolt front
    14 B FF Rear W/ Disc Conversion
    52/56 Spring Swap
    Cut Fenders and 37's
    Build thread
    http://www.chevyk5blazer.com/forums/...3-!&highlight=

  10. #10
    Knows their $hit AL P's Avatar
    Join Date
    Jul 2012
    Location
    FLINT MICHIGAN
    Posts
    614
    good thread...(bummer about the problem though)..anyway, I have a TBI, but having the same issue..just started the other day...lower/rpm miss...
    My 87 blazer..(RC 4in lift kit on the way..33 X 12.50 X 15 wrangler duratrac tires..just a tad worn..LOL)..My blazer runs pretty good, but I have found that it is infact NOT faster then a speeding bullet!!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •