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.

w t f ! damp or wet tbi prob

Discussion in 'The Garage' started by only 31s, Apr 27, 2005.

  1. only 31s

    only 31s 1/2 ton status

    Joined:
    Oct 5, 2004
    Posts:
    224
    Likes Received:
    0
    Location:
    mass
    when damp out [heavy mist ,fog rain conditions] 90 350 tbi acts like garbage , it spits and sputters idles vrey bad,but as soon as humidity lowers with a drying type of weather{as soon as 1 hour aftr a rain or fog} it clears up like nothing ever happend . I have swapped out cap wires rotor igncoil, hei mod,map sensor.I have also wet these areas manually and cannot get them to malf.Is there any other weather sensitive item i could have missed?
     
  2. diesel4me

    diesel4me 1 ton status Premium Member

    Joined:
    Jul 24, 2003
    Posts:
    17,540
    Likes Received:
    935
    Location:
    Massachussetts
    Icing up??

    Another post similar to yours about carbs on here too!--it could be icing up in the throttle body,just like a carb will when the humidity and temparature is favorable..add some dry gas,the isopropanol stuff,I bet it goes away...

    .GM has used "hot air pipes" to the air cleaner from the exhaust to help eleminate this problem,also the "heat riser"or "EFE" valve that blocks one side of the exhaust off and sends it under the carb via passages in the intake(not sure if EFI had them)..all I know is my truck runs like crap too when its cool,damp,raining or foggy under 60 degrees,until it warms up thoroughly(some days it wont go away!)...but adding the dry gas helped it a lot!...I had to "power brake" it at every red light and stop sign to keep it running!--dangerous,annoying,and not good for the tranny either.... :crazy:
     
  3. only 31s

    only 31s 1/2 ton status

    Joined:
    Oct 5, 2004
    Posts:
    224
    Likes Received:
    0
    Location:
    mass
    yeah baby

    :D wo hoo that was on the money!I happend again like clockwork[misty foggy] i barely made it down the road to the gas station and said ill try anything bought some drygas ,poured some down the tbi and the rest in the tank,as soon as i started it backup it worked perf!!! so now i have to figure out how to prevent it ? Thanks man !!!
     
  4. unclematty

    unclematty 1/2 ton status

    Joined:
    Jan 24, 2003
    Posts:
    3,164
    Likes Received:
    0
    Location:
    SLC UT
    I've kinda remidied this little phenominon, on a customers gmc pickup . I kinda made a throttlebody spacer out of a ford(god forbid I say the name) under carb heater, (sometimes called an anti-ice spacer) to bolt underneath the throttlebody on his truck, plugs in with a switch 12 volt pos, and a fuse (inline) and a ground. just sits there most of the time heats up when turned on and works flawlessly. I havn't seen the truck in a while I'll haveto calland check how it's working!
     

Share This Page