What gets wet?

[stomachmonkey]

It's been really damp in the Northeast this year.

Car runs like garbage after it rains.

It's fine after it heats up and dries out, usually 5 miles or so.

Wires are brand new, 2-k on them at most.

Checked cap and that is staying nice and dry.

Search yields mostly references to wires, which are new.

What else?

84 coupe, 112,000 on the clock.

Thanks,
Scott

[Por_sha911]

Although the wires are new, it is possible that one of them is
bad. I was thinking you had moisture under the cap but you say its dry.

[Gordo2]

Try some dielectric grease (a very small amount) around your plug wire fittings and distributor cap (where it mates with the dist).

4X4 trick that works equally well on our exposed engines.

Gordo

[xlr8]

Hi Scott, does your coil look like this-



Or does it have a raincoat?

[Paulporsche]

Have you examined some of the other electrical/electronic things, like sensors, DME and relay, etc?

Have you checked when damp & @ night to see if you have any wires arcing?

What start/drive problems are you having?

[kqw]

Check your Distributor cap again very carefully. A small crack is sometimes hard to see. If you have a spare, swap it out and before the next rain. See if problem persists.

[stlrj]

I found my Beru's were notorious for shorting wherever the wires enter the rubber boots. Even new wires had a tendancy to short out there so I tried sealing that area with some clear silicone sealer which solved the problem.

My 86 3.2 will even pass the garden hose test now, meaning I can spray water all over the engine while its at idle without a miss and then drive off as if they were bone dry.

I forgot to mention I also sealed my distributor cap with some Ultra Gray ( the same stuff the shop uses to seal my transmission pan in my Grand Caravan) on to the distributor so I wouldn't get any water inside the distributor too.

You may assume your Beru cables are fine just because they're new but as soon as you put the garden hose on them at idle, you'll see what I mean...

Cheers,

Joe

[djmcmath]

The garden hose test seems pretty ballsy, to me. Seems like its the kind of test that it would be pretty bad to fail. Never mind the fact that you're putting cold water on a hot engine block. Isn't that kind of bad?

Dan

[Mrdi]

I fine spay will do the trick
use a spray bottle

[stlrj]

Try to simulate what would happen in a carwash or heavy downpour.

[GettinHeadStuds]

Originally posted by djmcmath
The garden hose test seems pretty ballsy, to me. Seems like its the kind of test that it would be pretty bad to fail. Never mind the fact that you're putting cold water on a hot engine block. Isn't that kind of bad?

Dan

So never drive a pcar in cold rain or snow?

[Grady Clay]

So it never rains at Le Mans, Nurburgring, Daytona or Sebring? Race 911 never drive through deep water? Street 911s (and the race brethren) are designed to function in the wet, better than most. I’ve seen Cup cars almost under water.

You have a component failure someplace. Your challenge is to find it. Follow the advice you are getting here.
It may take some summarily replacing parts but it is solvable.

Best,
Grady

[djmcmath]

Good point, hadn't considered all that. My mistake was thinking that 911's were "normal" in some way.

Dan