>Just above freezing, heavy rain showers

>After a few minutes, misfires followed by stall at lights
>                        (checked electrical connections- noticed frost
>                         on intake plumbing below carb)
>                After a short wait with engine off, restarts, runs,
>                        still misses at medium-high revs
>                Rest of trip to work (half hour) the missing gradually
>                        diminishes and van will run at my normal 55-60 mph.
>                        (on arriving at work the intake is still frosted)
>
> Does this sound like a reasonable diagnosis?

The intake icing argues for it, but the symptoms also correlate with a wet
distributor. Did it bog when starting from a stop? Have to flutter the
accelerator to get it to go? That argues for icing.

Water in the distributor will tend to cut off and on hard. If it dies, it
dies all at once, then if you wait a while it'll start up fine and leave
you scratching your scalp. There is a tow truck driver south of Louisville
still laughing over the fact that I paid him sixty dollars once to come out
at 2 a.m. in the rain and watch me start my MG, which had been stone dead
before I hiked wetly to the pay phone.

Water can come in up through the bottom if your seal isn't good, or in
through the louvers. I'd hook up the pre-heater and silicone the wires
both.

KH