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.

Calling all engine guru's

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by k5wantabe, Jul 1, 2002.

  1. k5wantabe

    k5wantabe Registered Member

    Joined:
    Sep 3, 2001
    Posts:
    30
    Likes Received:
    0
    Location:
    So. Cal. Lancaster
    Calling all engine guru\'s

    Getting ready for a two week camping trip. So even though everything was running ok I decided to give the Jimmy a tune up. I changed the plugs(ac delco cr 43st) the wires(msd helicore) and the cap and rotor(stock autozone replacements). After the truck runs rough around 35-45 mph. I checked the wires (all 2k-3k ohms) and made sure all had good conections. Also changed the o2 sensor during tuneup. So put the original back in after checks and test drove it. Seemed better but still some hesitation (seems kind of like missing) at 35-45. Could it be a vacume problem /forums/images/icons/confused.gif I noticed that the previouse owner had ac delco 44T plugs in. They are a little shorter after the threads. (the center electrode doesn't protrude as far out as the 43st's.) Could that make a difference? I was wondering what those of you with ac delco plugs are using? Going to drive it to work tomorrow (66 round trip) and see how it goes.
     
  2. TX Mudder

    TX Mudder 1/2 ton status

    Joined:
    Jul 10, 2000
    Posts:
    2,514
    Likes Received:
    0
    Location:
    Houston
    Re: Calling all engine guru\'s

    I don't know the answer, but you could try posting at chevytalk.com in the Performance section.
    Just ask a question re: the difference between the two plugs and you ought to get enough info the help you figure it out.
    -- Mike
     
  3. Ovrtym

    Ovrtym Registered Member

    Joined:
    Dec 15, 2001
    Posts:
    21
    Likes Received:
    0
    Location:
    Virginia
    Re: Calling all engine guru\'s

    Just a thought, since you swapped out the wires/cap, double check the firing order to make sure the wires are going to the right cylinders.
     
  4. k5wantabe

    k5wantabe Registered Member

    Joined:
    Sep 3, 2001
    Posts:
    30
    Likes Received:
    0
    Location:
    So. Cal. Lancaster
    Re: Calling all engine guru\'s

    Checked out the firing order and the wires last night. Both good.
     
  5. Blazer_Boy

    Blazer_Boy 1/2 ton status

    Joined:
    Dec 16, 2000
    Posts:
    1,669
    Likes Received:
    0
    Location:
    Sioux City, IA, USA
    Re: Calling all engine guru\'s

    Pull some plugs out and have a look. They should have some color like brown, tan, or grey. Black would mean too cold and the 44s wouls be better. I believe that gaps on TBI plugs are .040. Kinda funny because HEIs were .045. Hell, check all the plugs while your at it. Check the firing order using 18436572 with the even bank on the passenger and the odd on the drivers (I know you probably already know that, but can never be too sure).

    You could have bumped the distributor too. Look on the driver's side where the wires come out of the firewall. One tan wire with a black stripe breaks out of the harness. Unplug that and start the truck. Time the engine to 0 degrees. Turn it off and plug that wire back in.
     

Share This Page