Blazer Won't Start When It Rains! Please Help!!!

I have replaced everything electrical; distributor, plugs, wires, coil, starter. It won't start if it rains, is misty or foggy outside or if it is really cold. It seems something is getting wet and it is driving me crazy. Once I eventually get it started I can shut if off and on easily, but if it sits for over a few hours I have the same problem. If anyone has any ideas I would greatly appreciate them. Thanks

Do you have fuel pressure and spark when it will not start???
Is the pcm in the engine compartment ??? check to see if its wet

I Do have fuel pressure and spark. The pcm is dry.

most generally when i have a vehicle that won't start when it's damp outside (also carwash, drive thru sprinklers) i can solve the problem by placing a beed of silicon caulk around the inside of the distributer cap so as to seal any leaks. i've found that this always solves the problem.

you might have bad plug wires if the insulation isn't good or thick enough so it is arcing to ground, if it isn't the plug wires your arcing to ground somewhere (get it nice and dark under the hood, have someone crank the engine and look under there because it is dark you will be able to see the sparks when it jumps to ground look over every thing eletrical do not crank over 15 sec. you will take the chance of ruining the starter...that would be bad) hope it helps :' )

cap & Rotor?

the cap is the "lid" of the distributer and the rotor is the thing on the inside that spins and makes contact letting current flow to fire the spark plugs

LOLOL, I know what it is.

I was asking a question if the cap and rotor has been changed.

Moisture or condensation in the cap and rotor will cause a no start.

You said you have fuel and spark so what is the fuel pressure reading while cranking. That is a must know reading.
What year is the engine and truck

the cap is the "lid" of the distributer and the rotor is the thing on the inside that spins and makes contact letting current flow to fire the spark plugs


Condensation is what happens to water when it changes from a gaseous state to a liquid....hope that helps

It's always been my idea that when a car runs poorly in high humidity conditions then the plug wires are bad. But it could also be somewhere else in the electrical system I suppose.

does it get wet inside your cab? if so water could be running down into dash or the steering column. check the connection to you ignition swith and such. just an idea.

another good idea would be to take the cap off and look at the distribertor. thy to put black or duct tape around your electrical connectors and next time it rains you canrule them out if it still wont start.

Dude had the same problem with my 97. brokndodge is right the cap is'nt seating properly use the caulk it works, but be neet about it.