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.

engine surging and dying on my way home w/ chattering noise

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 76_Cheyenne, Mar 30, 2003.

  1. 76_Cheyenne

    76_Cheyenne 1/2 ton status

    Joined:
    Jan 23, 2002
    Posts:
    285
    Likes Received:
    0
    Location:
    Missoula, Montana
    Had 500 mile drive home to Missoula from Seattle today and I didn't think I was gonna make it home.

    The truck: got a 350-th350-w/ recently converted to np205. The engines stock except its got headers and recently an Edlebrock intake and k&n air cleaner. The Carbs still the stock 4bbl quadrajet w/ about 80,000 original miles on the truck total. Also have a new fuel pump.

    The problems: Its been running great but about 300 miles into the trip coming up a pass about 3/4 the way up the truck felt like it was running out of gas. Surging, and almost dyiing. After each surge the rpms would drop lower and lower and wouldn't rev above 1900 rpm. I didn't think i was gonna make the hill. but on the way down it stopped. Then about 25 miles later it did it again on a flat stretch, then one more time up another pass, about 1/2 way up. This time when the rpms dropped so low i shifted down to 2nd and brought my rpm's up to 2700 where i usually cruise and it never surged or losed power. i could accelerate, and before the more gas i gave it the more it died. Each time i would pull over and check things out, but i could find nothing, In park i could rev it up and it runs great!

    Related noise?? im not sure if this is part of the problem, but recently after i converted to the 205, i've gotten a chattering noise every now and then, but im not sure where it comes from. Sounds like it comes from around inbetween the tranny and engine? Its like a cha-cha-cha-cha-cha chat-chat-chat noise. It DOESN"T get faster w/ the engine, always the same, and it comes and goes as it pleases. It happens most often every time the engine starts and when the engines colder. Could these be related?

    Sorry for the length... hope maybe someone can help asses the problem. Thanks /forums/images/graemlins/truck.gif
     
  2. 90K5

    90K5 1/2 ton status

    Joined:
    Jun 1, 2000
    Posts:
    3,719
    Likes Received:
    0
    Location:
    Lubbock, TX
    im having the same kind of problems with mine, but its a TBI motor. look at those posts for some help....sounds like it might be timing, that wasnt what was causing mine tohugh
     
  3. dyeager535

    dyeager535 1 ton status Premium Member

    Joined:
    Dec 13, 2000
    Posts:
    26,982
    Likes Received:
    191
    Location:
    Roy WA
    I had a similar problem that seemed to be based on fuel demand from the engine...If I cruised 60MPH, there was no problem, but any time I had to accelerate to pass (say around 70MPH) or climb a steep hill and press the accelerator a fair amount, chances were good it would start to sputter, and gradually lose RPM. If I let off the gas a bit, it would stop, but in extreme situations (like a hill) the RPM's would continue to drop as I attempted to stop the sputtering but letting off the gas, at one time actually killing the engine going up hill.

    My suspicion is the float. I rebuilt the thing before I put it on the truck, but I did notice on reassembly that the float arm seemed to rub a little on the casting (like it had warped) and I tried to "clearance" it best I could, but I knew it wasn't perfect. I haven't dug back into it, trying to force myself to get the injection swap done, but it's only done it once or twice *lately*.

    The only way I deduced it was the float sticking was the one time the engine actually died, I pulled over, tried cranking it a few times with no luck, then took the air cleaner off. Watching into the primaries while moving the throttle, there was no fuel being squirted as there should be, meaning the carb was devoid of fuel.

    My distributor was worn too (and I fixed it), but it was definitely not the problem.
     

Share This Page