Sudden stoppage due to ignition

[StephenGwyn]

My engine stopped suddenly this morning when it was good and warm and while running at cruising speed. Would not restart. No spark. I replaced points, condenser, cap and rotor. I was in a rush, due to currents pushing me towards rocks. Did I mention the fog? There was fog so I didn't set the gap exactly right. I could hear whales surfacing nearby as I worked. When I did that, it started right up. Later, when I was anchoring, it was idling rough. Fixing the gap seems to have fixed that too.

Questions:

In the past, problems with the contacts have manifested themselves as an occasional high speed miss, not a total loss of spark. What is normal for contact problems?

Can the rough idle likely a symptom of incorrect gap, or should I be looking for other problems?

[wristwister]

Of all the upgrades available for our old A4s, in my opinion the best one is the electronic ignition module. $100 and change from Moyer, minutes to install, ignition related problems gone forever.

[joe_db]

You may have well replaced everything but the bad part. Did you replace the coil? This is the classic bad coil issue, it will restart if it sits even with no new parts, but eventually it will get worse and worse. Do yourself a favor and replace the coil too if you haven't.

[JOHN COOKSON]

Questions:
In the past, problems with the contacts have manifested themselves as an occasional high speed miss, not a total loss of spark. What is normal for contact problems?
Can the rough idle likely a symptom of incorrect gap, or should I be looking for other problems?

I file the contacts on any and all points before I install them. It cuts down on the "drama".
R\E the rough idle: How long has it been since you serviced the advance under the distributor breaker plate? Also is the timing correct?

TRUE GRIT

[StephenGwyn]

I connected a new coil while adrift, but it didn't help, the engine still didn't start.

To be clear, setting the gap seems to have fixed the problem. It's more that this is not the set of symptoms I associate with contact issues.

[joe_db]

Points usually gradually get worse and usually the issue is hard starting. Did the condenser die?

[tenders]

Rough idle could be bad gas, sticking valves, gunky carb, mis-set timing, sticking advance springs, loose ignition cap, wobbly rotor, dirty contacts, failing condenser...I guess wrong gap wouldn’t help but it would be pretty far down my list as a cause for rough idle.

[JOHN COOKSON]

Problem: Rough idle
Theory: There is a points problem
Test of theory: Gap the points correctly then test the dwell. The dwell should be close to spec. The gap may need to be adjusted a couple of thousands to get the dwell correct. If the dwell is not to spec when the points are gaped to spec there is a problem. Possible problems: worn rubbing block on the points or worn distributor cam. Then at the carburetor adjust idle speed and idle mixture. If a satisfactory idle can not be attained there is another problem somewhere (see list in pervious post). This is how I got my idle down to 575-600 RPM.
Comment: Stephen, you are on the right track here. Sometimes one can get a engine to idle by speeding up the idle RPMs and\or adjusting the idle mixture. This will only mask the underlying problem which usually will only get worse not better.

TRUE GRIT

[Dave Neptune]

GAP ????????

Stephen, RE the gap fixing the problem. In many of these "old distributors" setting the gap is very inaccurate and gets worse with wear!! Once the points are installed and the engine is running CHECK THE DWELL and you will find that it is way off and to much "dwell". This is because the top of the cam in the distributor wears the most so a reduced gap is necessary for proper "dwell" or coil saturation (good spark). This excessive gap can cause "coil overheating" and lead to progressively shorter intervals between coil failure and once cooled the break makes contact again REPEAT scenario just like the EI issues you can read about on this site.

Dave Neptune

[StephenGwyn]

So after a few weeks, I can report that getting the gap right sorted out the rough idle.

As to why I don't have electronic ignition, it's because I did have it and it killed my coil, so I went back to points. I've got a new coil, but I haven't had time to install it. See the post by our host.

http://www.moyermarineforum.com/forums/showthread.php?t=171

Stephen