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.

Goes funky in third gear and shudders

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Blazer_Boy, Oct 17, 2001.

  1. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    1,669
    Likes Received:
    0
    Location:
    Sioux City, IA, USA
    I had a post a while back about this but I got a better explination now and tried some suggestions, but to no avail. 1981 w/'78 350/TH350c/NP208. On every third gear shift the truck feels like the RPMs are cut in half and the exhaust tone gets lower. It loses all guts too. When it does this and say I'm pulling an incline, it'll starting shaking and shuddering hard. Once its up to highway speed, its smooth sailing.

    I have replaced the vacuum modulator, vacuum advance, and fuel filter. I'm really running out of patience on this and its driving me nuts. It was only intermittent at first but now it happens on every third gear upshift.
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,979
    Likes Received:
    189
    Location:
    Roy WA
    Pull the electrical connector off the drivers side of the tranny and test drive it. Don't leave it unplugged for long, but if that fixes it when you test, its a bad TCC solenoid. Easy to fix.


    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>http://www.dorianyeager.com/index2.html</a>
    No anti-theft measures on your truck? No pity when its stolen
     
  3. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    1,669
    Likes Received:
    0
    Location:
    Sioux City, IA, USA
    Well crawled under it and pulled it off. I suppose about half of my part of town thinks that the guy in the rusty old Blazer is crazy. It was basically a drag race on any open area of street. I got it up to third gear and same ol' RPM drop and shudder up hills. I almost got it up to stall out on this big hill. I may be crazy but it seemed like it would shudder more after it was warmed up.

    <a target="_blank" href=http://www.geocities.com/bigkern76>http://www.geocities.com/bigkern76</a>
     
  4. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,979
    Likes Received:
    189
    Location:
    Roy WA
    Hmm..sorry to hear that. Is it shuddering/shaking like its running out of fuel, indicating you ARE running out of gas for some reason? (like float level too low?)


    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     
  5. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    1,669
    Likes Received:
    0
    Location:
    Sioux City, IA, USA
    First let me start of by saying that is one funny a$$ signature. Every person I know always says count the teeth. I just popped the cover on my soon to be installed 12-bolt and saw the magic 41:11 [​IMG] Why count when you dont have to?

    Anyways....That might be a possibility because I do see fuel leaking around the base gasket. The carb always smells real gassy too. It only does this goofy stuff in the low end of the third gear range, once its at speed, its fine.

    <a target="_blank" href=http://www.geocities.com/bigkern76>http://www.geocities.com/bigkern76</a>
     
  6. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,979
    Likes Received:
    189
    Location:
    Roy WA
    Thanks. Unfortunately I had to break that into baby speak, 150 characters isn't enough!

    You might try just tightening up the carb to intake bolts and carb screws to see if any are loose. You may think about "rebuilding" (re-gasketing if you ask me) your carb, to fix the leaks. However, just to check, try tightening them up. Do NOT go gorilla on those bolts and screws, or you will strip them out and bend the carb casting.

    Dorian
    My tech/links page: <a target="_blank" href=http://www.dorianyeager.com/index2.html>www.dorianyeager.com/index2.html</a>
    Why insist on counting when the ring gear has the tooth counts stamped in?
     

Share This Page