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.

Running odd

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Adub, Jun 20, 2003.

  1. Adub

    Adub 1/2 ton status

    Joined:
    Aug 16, 2002
    Posts:
    106
    Likes Received:
    0
    Location:
    OK
    89 Jimmy TBI 350 700r4. The truck is a dog until about 2700 rpms and its like someone flips a switch and it runs real strong. Its not just the truck hitting the powerband, its much more defined. It almost seems like timing is retarded until that point, then it gets going, but I don't know how to tell. Distributor, cap, rotor, plugs and wires are all new. It was doing it before I replaced distributor. Any ideas?
    AW
     
  2. rampage

    rampage 1/2 ton status

    Joined:
    Mar 20, 2001
    Posts:
    2,261
    Likes Received:
    73
    Location:
    Humboldt/Pacifica, CA
    An 89 is computer controlled and you're not suppose to mess with the timing, that's the computer's job.
    It's hard to tell from the description you give. It could be the fuel filter, fuel pump, lack of tranny fluid or a sensor. Could you elaborate on the problem a little more? Is the computer throwing any codes?
     
  3. Adub

    Adub 1/2 ton status

    Joined:
    Aug 16, 2002
    Posts:
    106
    Likes Received:
    0
    Location:
    OK
    Fuel filter is new, no codes thrown, tranny fluid level is correct. It don't know how to be more specific, it runs weak until 2700. Not rough, just no power.
     
  4. imiceman44

    imiceman44 1 ton status

    Joined:
    Aug 5, 2002
    Posts:
    15,160
    Likes Received:
    1
    Location:
    Sacramento, CA
    [ QUOTE ]
    Fuel filter is new, no codes thrown, tranny fluid level is correct. It don't know how to be more specific, it runs weak until 2700. Not rough, just no power.

    [/ QUOTE ]

    What kind of fuel octane are you running?
    Higher octane could cost you some power, on the other hand if the octane rating isn't high enough and it's pimging the computer will retard it to eliminate the pinging.
    Just two thoughts that contradict each other. /forums/images/graemlins/thumb.gif
     
  5. 87BrnRsd

    87BrnRsd 1/2 ton status

    Joined:
    Apr 21, 2003
    Posts:
    2,457
    Likes Received:
    0
    Location:
    Boone, North Carolina
    [ QUOTE ]
    An 89 is computer controlled and you're not suppose to mess with the timing, that's the computer's job.


    [/ QUOTE ]
    Thats not necessarily ture. Computers are only good for doing what we make them do. They cant think for themselves. On an 89 with TBI, it is ok to adjust the timing yourself. But, the only way to do this is to turn the truck off. When it is off, you need to unhook a plug on the drivers side of the engine, almost directly under the brake booster, that will have a I think 2 wires going to it. I know for sure that one of them is an orangeish tan color with a black stripe on it. It will go into a plug end, which will plug up to another plug (just like all of the connections on the engine), and if you trace the wires, you will see a tan and black wire goign to the distributor. With this wire unhooked (this will bypass the computer), start the engine, put a timing light on it, and adjust it to 0 degrees btdc. Once you get that, turn the truck off, and re hook the plug ends together, and whalla, timing is perfect. Just make absolutely sure that you unhook a plug with an ORANGEISH TAN WIRE WITH A BLACK STRIPE ON IT, and nothing else. If you try to adjust the timing with this wire still hooked up, it will mess the timing way up. I have seen people try to adjust the timing with the wire still hooked up, and once they learn to unhook that wire, they literally have to turn the distributor almost a full 180 degrees to get it right. /forums/images/graemlins/eek.gif But anyways, thats how you do it. /forums/images/graemlins/thumb.gif
    -Harrison
     

Share This Page