Ignition shutdown problem

[Jeff in TO]

Hey everyone,

My buddy's engine will run about 1.5 hours, starts and runs perfectly.. gets 'hot' and then shuts down on him. Won't restart until it's had a rest. Then starts and runs great all over again.

A4 (late model) Equipped with:
- mechanical fuel pump
- fuel water separator
- Electronic Ignition (from Moyer)
- Flamethrower coil

We sat tied to the dock this eve and ran it for about that long until it started to get all uneven and temper mental..and then eventually died. It would not restart.

- tested/rattled the ignition switch (push button type), no change but observed the backlights would light on the instruments when 'on', and off when off.
- pulled lead off the first plug, NO spark while he cranked. replaced.
- pulled coil lead off distributor, BIG blue sparks when cranking. replaced.
- re-tested first lead, NO spark. Same with second lead. replaced.
- re-tested coil lead, BIG blue sparks.

So it seems the "spark" is going IN to the distributor but not coming out when the system is in fail-mode.

I pulled the cap and rotor.. the rotor is ground down to a frickin nub. Cap looks worn too. So we definitely want to replace those... and there's definitely going to be an improvement after. But is this enough to allow the engine to run fine for 1.5 hours at like 2000 rpm's and then finally fail?

So some questions in addition; what do y'all think about the ignitor? Do these things ever turn rogue when they get hot? or intermittently fail like this?

And how do you feel about the coil? did my test above reasonably indicate a properly functioning coil?

I run the 'legacy' distributor and I would simply toss/replace the condenser, points, cap and rotor and I would know for certain after setting up that everything in there is new and in pristine working order.

How do you do confirm this with one of those damn EI things? Or is just silly and electronic ignitors never fail and likely the worn cap and rotor will restore all lost reliability to this ignition system and it will run happily ever after amen?

Thanks for reading, and for any suggestions or insight you may have.

Happy Sailing all. I gotta say you're a great bunch and this community has helped me in the past. I feel so happy to have bought a boat equipped with an A4 because of ..well you all!!

Sincerely,

Jeff

[romantic comedy]

Jeff, you might search the forum.

There has been long discussion about the coil and EI. Several guys here are very experienced with this. Personally I have the points and never had a failure.

It does sound like a coil failure though. Several guys have reported engines that run for a while and then stall, only to restart after cooling for a bit.

The guys will ask about the resistance thru the coil. Is there a resistor. Probably you will want to replace the coil.

The maximum suggested primary amperage is 4 amps. The coil will over heat and fail at a higher current.

[Jeff in TO]

Jeff, you might search the forum.

There has been long discussion about the coil and EI. Several guys here are very experienced with this. Personally I have the points and never had a failure.

It does sound like a coil failure though. Several guys have reported engines that run for a while and then stall, only to restart after cooling for a bit.

The guys will ask about the resistance thru the coil. Is there a resistor. Probably you will want to replace the coil.

The maximum suggested primary amperage is 4 amps. The coil will over heat and fail at a higher current.

thx, RC, I have spent some time Sunday eve and today searching through and I have read quite a few of those coil posts. I think I have also proven from the test above there's some kind of output from the coil and a stop inside the distributor somewhere. I've had a coil failure on my own engine and when it failed, there was no spark from the coil wire, then when cooled, sparks could be found both on the coil lead as well as to the plugs.

Have you had any experience with similar yourself?

Also very interested to know of anyone's experience with an EI failure, if anyone has ever been down that road too.

Jeff

[ndutton]

Your excellent description strongly suggests multiple issues. Let's address them all instead of looking for a single all inclusive cause.

1. Clearly, the rotor and distributor cap need replacement. Done.
2. It is also clear to me the coil has suffered multiple overheat episodes to the point of failure. It needs to be replaced even if it appears to work. Any of the EI/coil threads on the forum will explain why.

Be very careful when you select a replacement. If you are reluctant to go through the voltage and resistance assessment, buy a Moyer coil and you'll be good. Moyer coils are manufactured to Don's specification to meet the Atomic 4's unique electronic ignition requirements. If not a Moyer coil, please carefully go through either or both of these threads:

The full Monty: http://www.moyermarine.com/forums/showthread.php?t=5748
Cliff Notes version: http://www.moyermarine.com/forums/showthread.php?t=5845

I bet your buddy's problems will magically disappear.

[JOHN COOKSON]

Might as well replace the spark plug wires while you're at it just in case. What do the spark plugs look like? Do one or two of them look more grungy than the others indicating misfiring?

TRUE GRIT

Edit: How much corrosion is there in the towers where the where the spark plug wires push into the distributor cap (bet there's a lot) and also in the clips where the wires connect to the spark plugs?
Edit again: I guess you did replace the spark plug wires?

[Jeff in TO]

Thanks to all who read and responded.

My shopping list will be:

- cap + rotor
- moyer coil
- wire set

Hope everyone has a great summer season!

Happy Sailing,

Jeff

[ndutton]

Please report back when all is done. Good news is welcomed here.

[Jeff in TO]

For sure - I will do!

Also, so far not one of those who responded has commented on my question in the initial post re: the electronic ignition - should anyone have thoughts about this I would still be interested to know it!!

[Dave Neptune]

EI switching

Jeff, I have run an EI on my A-4 now for just over 30 years. In those 30 years I have never had an issue even before the "resistor" dwell~& heat stuff due to higher voltages in newer systems! I did replace my original EI that I adapted to the distributor myself. When a new model with an indicator lite became available I bought it.
Testing the EI is nothing more than looking for spark! The EI is nothing more than an electronic switch just like the points are a mechanical switch. If the switch fails no spark. You can test an EI when cranking with a volt meter on the negative side of the coil, look for on~off pulsating or a fluctuation in the voltage reading that means it is switching so the problem may lie elsewhere in the ignition. And you must also be sure the EI is getting a good source of power when checking the EI.

Old distributors and their cams are just wore out and getting the proper dwell no longer has much to do with the clearance setting of the points . The timing also varies as the points wear and an EI never needs to be moved once set.

Hope this helps.

Dave Neptune

[ndutton]

Also, so far not one of those who responded has commented on my question in the initial post re: the electronic ignition

What do y'all think about the ignitor? Do these things ever turn rogue when they get hot? or intermittently fail like this?
No, we haven't seen a verifiable indication of this.

And how do you feel about the coil? did my test above reasonably indicate a properly functioning coil?
No. Damaged coils will fool you into thinking they heal themselves when they cool down only to fail again when they heat up.

I run the 'legacy' distributor and I would simply toss/replace the condenser, points, cap and rotor and I would know for certain after setting up that everything in there is new and in pristine working order.
No. The accepted practice is to save the points and condenser mounted on the original distributor plate as a backup in case it's ever needed.

How do you do confirm this (proper operation) with one of those damn EI things?
What Dave said. If you have spark, the EI is working.

[Jeff in TO]

So, just to close the loop.

coil, cap, rotor, wires, all replaced.

Runs great. We ran at the dock for about 1h 20min and we felt satisfied we have restored reliability.

Thanks to everyone.

Jeff

ps-

One interesting point, the Moyer rotor I bought seemed incompatible with the EI magnetic ring. The rotor wouldn't press on far enough for it's 'key' to sit firmly into the groove on the distributor shaft. I happened to have 2 other new ones onboard my boat so I swapped it for another one which seemed to have a slightly deeper 'key' portion (the little nub inside the head of the rotor). It fit firmly into place, and did not allow the rotor to turn independently of the distributor shaft - the Moyer one would spin freely.

I thought it was perhaps telling of the condition of the old rotor (from my original post). Maybe someone tried to replace it and found the new one didn't fit right so they left the old one in place.

Does this indicate a possible problem with how the EI was installed? can that magnetic ring be adjusted for height? maybe the way it was installed it's just set a fraction too high? I think 1/16" may make the difference.

[ArtJ]

I had a problem with the magnetic ring not sliding far enough on the
rotor shaft. Spoke with Don Moyer he suggested using a hair dryer
to heat the magnetic ring sufficiently to enable it to slide down the
shaft to the proper distance without breaking. Be sure to accurately
measure the distance recommended in his installation instructions.

Regards

[krazzz]

I agree, I think it is more likely that the ring isn't down far enough rather than the rotor being bad. I have the electronic ignition and I bought a new rotor from Moyer.

[Jeff in TO]

Thx for the thoughts - this is my friend's boat and I didn't install the EI.

IF the ring could move down the shaft slightly further it would solve the issue for sure - I do not think it's a bad rotor either - probably the spec on some is slightly different than others which allowed one of my spares to fit.

I will look over his instructions next time I'm onboard to see the measurement.

Jeff

[ArtJ]

Thx for the thoughts - this is my friend's boat and I didn't install the EI.

IF the ring could move down the shaft slightly further it would solve the issue for sure - I do not think it's a bad rotor either - probably the spec on some is slightly different than others which allowed one of my spares to fit.

I will look over his instructions next time I'm onboard to see the measurement.

Jeff

There are differences in shaft diameters on distributors as several of us
have seen and broken mag sensor. Again, as recommended by Don Moyer,
I heated the magnetic sensor and was able to push it down to the
recommended position.
I don't know why they don't update the
instructions to mention this to avoid others having the same issue
and potentially broken/ cracked mag sensors.