I thought I would report on a strange experience I had recently with a New Day Timer.
About a week ago I was driving about a mile from home when a heard a clatter. Very shortly thereafter steam started pouring from under the
hood. Turned out that the bolt holding the fan assembly had loosened and allowed the fan to come in contact with the radiator, cutting a small hole in it. Fortunately it was easily fixed as it had made a small slice in the lower tank about and inch long and less than 1/8" wide. A little silver solder and it was as good as new.
Here's where the fun started. I reinstalled the radiator and started the car (15 touring). It ran terribly, obviously missing on one cylinder. I checked with the screwdriver to plug shorting test and #4 wasn't firing. OK, lets change out the plugs & restart. Oops now #1 isn't firing. %#^&^%$&^$^. OK lets replace coil #1 with a spare coil .... ran very slightly better (not much). Checked the coil box for carbon traces - clean as a whistle. OK time for a test drive down to my friends house down the road. At this point it still idled badly and to idle at all the spark lever had to be halfway down. At 25 mph it would die if I put the start lever in the normal running position - it had to be at 3/4 down (or more) to run at all!
I pulled the New Day timer off. (it was NOS - one of the good ones). It had a little erosion of the bakelite material next to the contacts, so I replaced it with a new New Day (again NOS). Started the car and NOTHING had changed. Still ran terribly. Took the timer off and wiped it out with acetone (it had a thin coating of oil inside ... still NO difference. Took it off again and cleaned the wiper with acetone and snapped it in and out to make sure it was free and the spring was working.
Replaced the timer cover, started again, and she ran as sweet as it ever did. Not just better, but as well as it ever did.
Now I'm not complaining, its fixed and that's a good thing. But I'll always wonder what the heck was going on. Any ideas?
With time the brush spring becomes weak, making contact intermittent. But be careful if you stretch the spring. Getting contact too tight can be trouble too.
Check the timer wire for #1... frayed strands? questionable terminal connection/solder ?
Broken or poor wire connection... & you just happened to move it into the right position the last time you re-installed it...
I drive a few thousand miles a year and regularly inspect & clean the timer. I usually have to replace and re-solder the timer wire terminals every few years.