when raining 350 runs like crap

Discussion in 'The Garage' started by adamforsythe, Apr 27, 2005.

  1. adamforsythe

    adamforsythe 1/2 ton status

    Oct 16, 2004
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    When ever it is wet outside my 350 runs like crap. It wil not idle when I come to a red light it wants to die. But just as soon as it starts to dry up outside the truck runs like a champ.
    I will be pulling this engine in a few weeks to dress it up and add a few goodies.
    The engine is a Mr Goodwrench engine
    It has less then 15,000 miles on it. It has a Accel super coil, High preformance wires. *Edlebrock fuel filter, 600CFM carb, EPS polished intake.
  2. dheavychevy38

    dheavychevy38 1/2 ton status Premium Member

    Jan 6, 2003
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    I would check your cap, rotor, coil, and wires. I bought a new accel coil and when it would rain hard the truck wouldn't even run so i would check that suff.

    When it is dry start the truck get a water bottle and start spraying the components one buy one till you get the sympotoms
  3. ramjet gmc

    ramjet gmc CK5 Staff Staff Member Moderator GMOTM Winner

    Dec 19, 2001
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    Milltown NJ 08850 NJ sucks
    has a Accel super coil----- ther is your problem i would bet on it i had the same thing with mine it you look at the back of your hood it lines un with the coil and cap combo mine got water in every time i removed the cap/coil combo and went stock and it was just fine -- just for info i tryed to fix the cap like 6 times what a PITA :mad:

    good luck with your truck
  4. Russell

    Russell LLY Escalade Status Premium Member GMOTM Winner

    Jun 23, 2000
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    Edmonton, Alberta
    My old 350 did that too...

    Didn't have to have moved anywhere, just ran poorly when it was super humid outside. Even driving into the carwash would cause my truck to suddenly begin to run poorly
  5. pauly383

    pauly383 Daddy383 Staff Member Moderator

    Jul 22, 2001
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    Mesa , Arizona USA
    Y acan get it to stop dying with some tuning , but generally the weather will make it run a bit different anyway .

    When its dry and cool , my 305 runs like a 350 , but when its 110 and humid during the monsoon , it runs like a 267 :D
  6. diesel4me

    diesel4me 1 ton status Premium Member

    Jul 24, 2003
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    Does it skip??

    When it starts running lousy,is it skipping,or just stalling out at idle??--I'd try adding some isopropanol dry gas and see if it improves...I have the same dilema in my 79 C10 with the 305--I thought it was plug wires,but soaking them with the garden hose had no effect,and they are fairly new--and it didn't "skip",it would just idle lower and lower until it stalled..

    I noticed it was much worse in the colder weather,and it was hell to drive on cold damp misty days,it will stall at every stop sign or redlight,until it runs for 20 minites or more,on cold days sometimes it never went away!--I drive my diesel truck on days like that(no plug wires,no carb,NO PROBLEMS! :waytogo: )

    I discovered it was the carb icing up!--frost would build up around the butterflies in the carb and clog it,snuffing all air to the motor!--it will do this even all the way up to 55 degrees on days with rain,or drizzly conditions,which we have a lot of here....I got the OEM "hot air" pipe and the aircleaner on it,it helped some,but did not cure it-

    -I think if I hook up the "heat riser" butterfly in the exhaust it would solve it completely--but I found using the dry gas eliminates 95% of my aggravation,and it doesn't do it after may until october,so I probably will just use dry gas when it acts up... none of this would be happenning if I had left the quadrajet carb on it--my edelbrock performer requires an adapter,that blocks all the heat the carb needs to run right from getting to it...they make ones with water jackets in them you tap into the heater hoses,some motors wont run for crap without heat to the carb..:crazy:

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