Stumbling in the rain?

Engine troubles? Try here.
kdiqq
United States of America
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Joined: Tue May 26, 2015 3:30 pm
Location: Houston, TX

Re: Stumbling in the rain?

Post by kdiqq »

I actually drove in the rain again and my issue is cleared up!

Sealing the distributor didn't help, though I still left the vent holes open. Switch from the military coil to the sealed civilian version seems to have to running well. I massaged some of the engine shrouds to better direct rain away from the junction block and coil, but I don't suspect that did much. I went through and redid all the ignition connections with marine heat shrink too. So far so good! Still would really like an SSI though.
1977 Austrian 710M
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audiocontr
United States of America
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Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Re: Stumbling in the rain?

Post by audiocontr »

I'm sorry, i dont recall... Did you have a vent line on the distributor?

I'm going to assume you did, and I assume it connected without the restrictor. I apologize if it was said elsewhere that my assumptions are incorrect.

Full vacuum will pull moisture in, which may be why sealing did not solve the problem. You may have pulled moisture in through the vent hole. This is easy to determine by popping the distributor cap off and looking for moisture. Its very evident when there. WD40 bath, and should start right up.

Partial vacuum will help pull moisture out without sucking moisture in. Its truly a very slight vacuum.

Given all of that, wouldnt a cracked or defective ignition wire also arc in moisture?
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
JimmyC
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Joined: Tue Feb 18, 2014 4:59 pm
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Re: Stumbling in the rain?

Post by JimmyC »

I think I have this problem too. Intermittent rough running, misfires, and low power, particularly at low rpm. It seems to fix itself which confuses things. Once it was clearly water in the distributor cap so I am going with that for now. I have the Petronix civilian conversion with the vacuum vent. The orifice is plugged so I tried to clear it with no luck. I can’t see well enough to see exactly what it is. Is it just an orifice or is it some sort of check valve? I tried clearing it with my smallest drill bit but it was too big and I could not poke through with a torch tip cleaner. If it is an orifice, does anybody know the drill size?

I pulled the distributor and soaped it up and blew a little air into the vacuum connection. I got plenty of bubbles everywhere - between cap and adapter, adapter and distributor, and out of the six vents.

I am going to do what I can to limit the venting to the vents and replace or clean the orifice. It would be neat to supply the distributor with dry air, but I can’t think of a way to do it.

I suspect that vacuum line is supposed to suck up liquid water from the bottom of the housing. It is at the bottom like a drain.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
JimmyC
Posts: 217
Joined: Tue Feb 18, 2014 4:59 pm
Location: Lafayette, LA and Highlands, NC
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Re: Stumbling in the rain?

Post by JimmyC »

I replaced the orifice and it completely fixed all my problems.
Jim Chance
710M

All my post fully incorporate the Dunning-Kruger effect
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