runs bad when wet
Senior User
Joined: Nov 2000
Posts: 233
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runs bad when wet
i got a 1980 f150 300 i6 duraspark II. in the past 4 months i put on a new carb, fuel pump, dist cap, rotor, plugs, wires, ignition module. it ran great for months until now. when it is damp, after driving it for awhile, it will run like crap. when its dry out no problems at all. if you shut it off for 10 min or so it will run great but have a low idle almost stalling then it will pick up and idle normal. i was thinking of taking of all the emmision stuff like the egr. the guy that had it before me poked a hold in the egr and plugged the hose. i did notice that spraying carb cleaner in it makes it drop idle. any ideas?
Postmaster
Joined: Jul 1999
Posts: 3,172
Likes: 4
runs bad when wet
It sounds like the carb is icing up during conditions when the temperature is low & the humidity is high . Anytime when the temperature & dewpoint are within 6 or 7 deg of one another icing can occur . Make sure the heat stove is in place on the exhaust manifold & the hose from it up to the air filter housing is intact . Also the Egr Valve helps to keep the upper intake area warm during steady cruise speeds when ice may form .
Senior User
Joined: Sep 2000
Posts: 147
Likes: 0
runs bad when wet
You may have a crack or seal leak around your distribuiter. Try wd-40 or a silicone spray around the base of the cap. If that does not fix it, try a can of dry gas. I found that water in the fuel & rainy wet days do not mix well.
Good Luck
Walter
Good Luck
Walter
Senior User
Joined: Nov 2000
Posts: 233
Likes: 0
runs bad when wet
today i heard a very weak hissing out of one of the head bolts when i was spraying water looking for a vacume leak. when water was in there the idle seem to smooth out until it evaporated. can i put some high temp liquid gasket on the bolt head. im not burning oil or coolant and i dont want to replace a head gasket for nothing
