Just wondering if anyone has any suggestions. When it rains or snows, my truck will not idle. This is very tough in traffic with a granny 4 speed with a non-syncro first. My truck is a 1978 Dodge W150 with a 360. The cap and rotor are new. I have tried siliconing the cap to the accel distributor, and the new plug wires to the cap. The plug wires have dielectric grease at the plugs, and the wires use two sets of wire seperators to make sure no wires cross except at right angles when they must cross. I have even siliconed the ECU plug to the ECU. My truck runs a Crane HI-6S ignition which is mounted under the dash to keep moisture away. Several times i have tried WD-40 or wire drier on the wires and cap. I even Soldered a ground wire to the ECU case and ran it directly back to the battery in case it was a ground issue.

Any Suggestions? This problem was bad enough when I ran the 727 trans, but now as a standard it is even worse.

What kind of carb/filter?

Holley truck avenger with a 14" K&N Filter.

Throttle blabes frosting over/freezing.. next time it does it pull the aircleaner off and see if you see frost/ice..

I will certainly check that out. It also does the same thing when it is warm and raining.

So you go outside and its not raining and it idles fine, as it's sitting there running it starts to rain and it just dies? :confused:
Explain what would happen in this situation.

If it is raining at night, I go outside in the morning to drive to work. Start the truck, and it will not idle. you have to keep your foot slightly on the gas peddle to keep the idle at a grand. Depending on how wet it is outside, if you take your foot off the gas, it will either barely idle at a few hundred RPM and then die, or it will almost instantly die when you take your foot off the gas. If it I leave and it is dry out but starts raining during my 1 hour ride to or from work, then there is a possibility that by the time I get home, it might be running ok, or it might not want to Idle.

I would hit it with the garden hose and see if I could pin point my problem.

Sometimes the simple replies are the best ones. I feel stupid for not thinking of the garden hose myself. Once the actual rain stops, I will try this. Today the truck was at its worst yet. backfiring through the carb and tailpipes while trying to drive down the road. Thinking of trying a Davis Unified Ignition (D.U.I). Has anyone used one of these?

i run a DUI ignition. from what i can tell it's basically just a chevy HEI designed to fit other type engines. i like it. it cleaned up my engine compartment, 1 wire hook up and DUI will ask you questions about your application and tune it for your needs. such as: prefered octane, cam selection, vehicle weight, prefered RPM range, intake, ....blah blah.

edit- get the clear cap, it makes wondering if you have power to the plug wires easy and entertaining.

Have you checked out the coil?

sounds like the distibutor cap is cracked to me.

I really don't think this will help you, but just incase..

I really have somewhat the same issue on my CJ7 with a 304... of course carbed as well. Except mine will do it when its been a frost or freezing temps. After it wamrs up its not as bad. The carburator has been rebuilt and heats up the choke properly. What I do, and its only thing I know to do, is after driving it for a while I pop the hood and take the oil breather off, letting the steam out. I usually just lay the hood down with the breather off and leave it for a while. This usually solves my problume for a few days.

My oil breather connects to the carb's breather and I sometimes find a lot of oil and moisture gettin into it. not a good thing since it never happens, someone told me I overfilled it with oil.... but I drained every bit and put the same amount back in.

so what did you find?

Sorry guys, I had gone away for the weekend and just got back around to checking the post. After all the problems I had Friday morning, when I tried to start the truck after work, it would only crank. On the walk back from Napa to get some starting fluid, I decided to pop the cap. The cap had a ton of water. It is not cracked, it was replaced a month or so ago. I have checked the cap before and not found any moisture, but I have to think this is the whole cause of all my problems. Thinking that this weekend, I might try to drill a hole in the top of the cap, and run a hose into the air cleaner. Hopefully the vacuum from the carb will draw the moisture out of the cap if/when it forms, before it has a chance to build up.

That sounds like a good idea, I have no clue on if it works (I really shouldn't be given any kind of tool to use on a car...) but if you get water up in the breather would it cause yet another problume (Wouldnt be good to splash down into a creek and die!) Thats all that comes to my mind.

just a thought

If you run a vacumn line to the air intake for vacumn, And then you got some fuel mist back into the distrubuter cap couldn't the cap light off and go boom? Now there's a under hood fire you weren't expecting.

I maybe thinking of the wrong year but were these trucks called the bird-bath hood? If so don't they slosh alot of water all at once back and at the distrubuter. Maybe a rubber flap there might help you out?

good luck

Yes, my 1978 has the hood with the recesses in on drivers and passengers sides. They do hold a lot of water, that sloshes back. However, the front of the cowl that the hood mates to, forms a slight shelf that I would think stops the majority of water from hitting the distributor. I admit that I am a little nervous about the spark in the distributor igniting fuel fumes if I run a breather tube to the air cleaner, but not sure what else to do. Just need something that will help draw moisture out of the cap before it can collect.

what about silica packets?

Dont band-aid the problem, solve it. Water is getting in your distributer cap somehow. Seal that puppy up. Im not real fond of providing a path for a flamable fuel/air mixture to get to an ignition source. Just dosent seem like a real good idea. Get yourself a tube of silicone and go to town on the cap. Seal that puppy up.

I do not want to band-aid the problem. I want to fix it for real, but have struck out every time. in my first post I mentioned that I have siliconed the cap to the distributor, the plug wires to the cap - the only thing I have not done is siliconed the vent cap in the top of the distributor cap closed. I guess that would be my only option left. But that is suppose to vent any gases and such.

Well, we know what the problem is: Water in the disy cap. Ya just got to figure out how it is getting in there and prevent it from happening. Could the new cap be warped or cracked or something?

I have in the past used a 2-liter bottle bottom to cover my disy when playing in the mud. Just an idea for ya.

I have had this problem for years, and have tried many different brands of caps. All had about the same problem. Thinking maybe I will silicon the cap back to the housing, silicon the vent button closed, and drill the cap to run a hose into the cab. I kind of like the bottle cover idea. Years ago, i had a Samurai that would not run when I tried to hit the mud while 4wheeling. For that I used a latex glove, cut the finger tips out so I could run the plug wires through (worked perfect because there was 5 fingers, and 5 wires), then zip tied everything closed. After that, I NEVER had ignition problems.

just sprey some Wd-40 in there and see what happens, after all WD stands for water displacement...

what if you used an axle vent, drilled the hole in the rotor where the gasses escape large enough for the axle vent...then run a hose from it and coil it a few times. are you getting water in it because of the rain....or could it be moisture in the form of condensation. what if you wrapped the outside of it with a form of insulation?

:flipoff2: get a life drive a jeep :flipoff2:

I think the moisture is more from condensation for the most part, but I can not rule out actual water getting in it at this point. That is the reason I was thinking about running a hose to the air cleaner thinking the vacuum would help pull any condensation out of the cap. Since posting that idea, and getting feedback about possible fires, someone else told me that it is not the air cleaner I want to run the hose to, it is the PCV port on the carb.

But why is it, or how is it getting in there?

Wish I knew why it is, and how it is getting in there. If I could figure that out, then fixing would be simple