New a4 owner hoping for some assistance

[stranded-sailor]

Good day all, recently got a boat with an a4 and am sailing home. Having a little engine trouble and would be thankful for any suggestions/assistance. Have only been operating this boat for 2 weeks now, everything has gone well getting things to rights. I've put a new coil on because the first couple times running the engine would shut down almost exactly on the 30 minutes mark so figured bad coil. After this everything appeared to work fine and I started home. Its been good until on leaving the last port my alt belt broke. I have only an oil pressure gage so I didn't know anything was wrong until engine quit. No bad noises, no studder, just shut off. i had a fair ways to go so I just left it and went about business. Now that I'm on dock again I've replaced belt and had no start. I'm finding the coil heating up with just the key on, no attempt to start. Just checked spark and don't seem to be getting any. Do I just have a bad coil? Coincidence? Or from something to do with belt? Sorry this is a little long and thanks in advance for any tips to get me on the right track.

[joe_db]

The only way the alternator belt will affect the engine is from the battery(ies) going dead. Did you notice this happening?
Having the key on but the engine not running will eventually burn up the coil and/or the points.
If there is an issue with the wrong types of coils being used, they will continue to burn out.

[hanleyclifford]

If you are going to operate an Atomic 4 I suggest you own a digital voltmeter. Next time you get the engine started take a reading at coil +. If the value exceeds 12 volts you need a resistor in front of that coil. There is a lot of discussion relating to coils on this forum and you should review it.

[stranded-sailor]

I do have a digital volt meter. I attached a photo of my coil and distributer. I believe its been changed from original. There is a + and - from dis and 2 other + wires on coil. I'm wondering if there is a pre existing problem (before belt broke) that caused the other coil to go bad. Engine has not been used in approx 5 years. But sounds perfect even right up to last shut down when it stalled.

[hanleyclifford]

Originally Posted by stranded-sailor

I do have a digital volt meter. I attached a photo of my coil and distributer. I believe its been changed from original. There is a + and - from dis and 2 other + wires on coil. I'm wondering if there is a pre existing problem (before belt broke) that caused the other coil to go bad. Engine has not been used in approx 5 years. But sounds perfect even right up to last shut down when it stalled.

That's what happens. The coil does ok until it doesn't because it got over heated. The A4 will run just fine at 10 volts measured at coil positive running. But if you pump full alternator voltage (14v+?) into coil+ the engine will run until the coil cannot take it anymore. In most cases the coil will work again after it cools off, but in the long term it's fate is sealed.

[stranded-sailor]

Without buying and ruining another coil is there a way to test regulator? Would the regulator be in the alt itself? This has a new alt in it also due to original not charging. Took to alt shop told me was the stator and sold me a new one. First was simular to a chev ac Delco with only one wire to it (bat +) but was too large and bracket hit body not allowing it to adjust. Got another which was better but same problem. This one is a 2 wire (bat+ and one to coil. Could something here be my problem?

[stranded-sailor]

Also is it normal for the coil to become noticeably warm, like almost enough to call hot, within a minute of key being turned on, no attempt to start engine?

[hanleyclifford]

If you turn the ignition on without starting the engine and the points are closed you have effectively created a short circuit which will get everything hot and burn the points. It is quite normal and necessary for alternators to put out 14 volts+. But the coil doesn't want that much, nor in fact do other things on the boat; therein lies the reason for a resistor.

[stranded-sailor]

I understand the alt voltage output (mine is 13.5 as measured at bat + on alt grounded on block) vs what everything needs to run. I'm not mechanically enept as my base in collage was diesel mechanics, I am just unfamiliar with this engine and not as up on gas period hence the difficulty trouble shooting ignition issues as diesel is obviously completely different. A little guidance would be great. Is it possible that there is a regulator in this new alt that is giving too much juice? I'm good doing lots of things but electrical is my weak point which is why I came here.

[hanleyclifford]

Originally Posted by stranded-sailor

I understand the alt voltage output (mine is 13.5 as measured at bat + on alt grounded on block) vs what everything needs to run. I'm not mechanically enept as my base in collage was diesel mechanics, I am just unfamiliar with this engine and not as up on gas period hence the difficulty trouble shooting ignition issues as diesel is obviously completely different. A little guidance would be great. Is it possible that there is a regulator in this new alt that is giving too much juice? I'm good doing lots of things but electrical is my weak point which is why I came here.

Actually your alt output is low for my liking. 14 is the minimum I would accept. Sounds like your alternator is internally regulated and thus not adjustable. I use an external regulator with potentiometer which allows me to adjust the output voltage of the alternator. But for now that is not your issue. You need to discover what is being delivered to coil+ and get it corrected if needed; otherwise you will just keep frying coils. You should also have a dwell meter to make sure you are in range.

[Dave Neptune]

The voltage you have is OK only if the batteries are fully charged up however 13.7 is better. You should see a bit more voltage up to 14.2 if the batteries are low and charging. Not a really big deal either way "yet".

If you tend to or ever do leave the ign key on it is very easy to fry any coil. Another possible issue is the type of ignition you have either points or an electronic one. If you have points your voltage should be OK unless the points are set with far to much dwell which is hard to set on an old distributor as the point cam is probably worn, thus setting points should be done with a dwell meter. If you have an electronic ignition a simple resistor is usually included and mounted in the feed to the + side of the coil. If not get one from MMI if you have the Pertronics one or from Indigo if you have the Indigo style. There are many threads on this site concerning the EI and resistor issues. Also the correct coil with either ignition style is a must as not all 12v coils are the same.

Leaving the key on happens more often that you would think especially when chasing or diagnosing an ign problem.

Dave Neptune

[stranded-sailor]

I agree I prefer my v a little higher at the alt. Being that my old one did not give anything I accepted this for now so I could get home and start redoing things. So I've just put my old coil on, which worked but only for a time when I removed. Now no start with that either. Seems no spark. I don't think I have points, had a automotive mechanic helping me a bit where I bought this and he said its been changed to a condenser. Theres power to the coil with key on. Could condenser be bad? How to check?

[Dave Neptune]

A condenser is used with points and it is easier to replace that to check and it is a cheap part. It could be a loose wire on the points to condenser connection or a wire could be grounding out from being clamped under the cap. That will short out the ignition. Sometimes the points wire just plain ole wears off some insulation and grounds out once in a while. Check the wires under the cap closely for worn insulation.

I would also suspect the "mechanic" as saying it is an electronic ignition and then saying it may be the condenser leads me to think he didn't really inspect or has no real idea how the ign system actually works.

Dave Neptune

[stranded-sailor]

Originally Posted by Dave Neptune

The voltage you have is OK only if the batteries are fully charged up however 13.7 is better. You should see a bit more voltage up to 14.2 if the batteries are low and charging. Not a really big deal either way "yet".

If you tend to or ever do leave the ign key on it is very easy to fry any coil. Another possible issue is the type of ignition you have either points or an electronic one. If you have points your voltage should be OK unless the points are set with far to much dwell which is hard to set on an old distributor as the point cam is probably worn, thus setting points should be done with a dwell meter. If you have an electronic ignition a simple resistor is usually included and mounted in the feed to the + side of the coil. If not get one from MMI if you have the Pertronics one or from Indigo if you have the Indigo style. There are many threads on this site concerning the EI and resistor issues. Also the correct coil with either ignition style is a must as not all 12v coils are the same.

Leaving the key on happens more often that you would think especially when chasing or diagnosing an ign problem.

Dave Neptune

So I checked and I don't have points. Here's a pic with distributor cap off. I put old coil back on, which was working before I changed to new one but was stalling after half hour and now no start. Is there a way to check this condenser?

[stranded-sailor]

Originally Posted by Dave Neptune

A condenser is used with points and it is easier to replace that to check and it is a cheap part. It could be a loose wire on the points to condenser connection or a wire could be grounding out from being clamped under the cap. That will short out the ignition. Sometimes the points wire just plain ole wears off some insulation and grounds out once in a while. Check the wires under the cap closely for worn insulation.

I would also suspect the "mechanic" as saying it is an electronic ignition and then saying it may be the condenser leads me to think he didn't really inspect or has no real idea how the ign system actually works.

Dave Neptune

Sorry I may be quoting him wrong and using wrong name. Its been awhile since I've done much mec work, done my own before but more diesel oriented

[hanleyclifford]

Since we now see that you have electronic ignition the dwell issue is settled. It is fixed maybe around 55 degrees which is way more than the points type ignition. It also means that the voltage at coil+ is even more important to know since that EI dwell is pushing a stronger belt thru that coil. Resistance is even more mandatory (if you'll pardon the expression).

[stranded-sailor]

Originally Posted by hanleyclifford

Since we now see that you have electronic ignition the dwell issue is settled. It is fixed maybe around 55 degrees which is way more than the points type ignition. It also means that the voltage at coil+ is even more important to know since that EI dwell is pushing a stronger belt thru that coil. Resistance is even more mandatory (if you'll pardon the expression).

Resistance is always mandatory!! Sorry, had too. Lol
Coil resistance across small posts is 1.9 when set on 200 setting. Resistance from center is 8.10 on 20k setting.
Your meaning v at coil + when running correct?

[joe_db]

1.9 ohms across the coil primary is WAY low. They will burn out. You want around 4 ohms or so.
My coil is about that as-is, but if you don't have one with that much resistance you can either buy a new one that does or add a ballast resistor.
We also have the issue of the electronic ignition itself burning out, which is rare but not impossible.

[joe_db]

It just so happens our host sell the correct coil to solve this issue:
https://moyermarine.com/product/coil...ce-iglm_05_31/

[stranded-sailor]

Originally Posted by joe_db

1.9 ohms across the coil primary is WAY low. They will burn out. You want around 4 ohms or so.
My coil is about that as-is, but if you don't have one with that much resistance you can either buy a new one that does or add a ballast resistor.
We also have the issue of the electronic ignition itself burning out, which is rare but not impossible.

I looked up resistance values for coil and found this

a 12 volt coil will have a nominal resistance of around 1.5 ohms give or take a couple of tenths. The secondary resistance should be at least 8,000 ohms and can go as high as 12 to 13 thousand ohms depending on the coil

Is the coil for the a4 different? I got this replacement coil at a car parts place. Looked at my old one and said this one would work.

[hanleyclifford]

Originally Posted by stranded-sailor

Resistance is always mandatory!! Sorry, had too. Lol
Coil resistance across small posts is 1.9 when set on 200 setting. Resistance from center is 8.10 on 20k setting.
Your meaning v at coil + when running correct?

Right, voltage at coil+ engine running is where the rubber meets the road. Doesn't matter how you get there. I don't like coils with internal resistance because they do not afford the opportunity to monitor voltage where it matters. The internal resistor may indeed reduce the voltage to an acceptable level but you cannot measure it, and because the resistor is in the coil there will be heat generated. Heat is the enemy of electrical devices, yet ironically most do produce their own heat.

[hanleyclifford]

Originally Posted by joe_db

It just so happens our host sell the correct coil to solve this issue:
https://moyermarine.com/product/coil...ce-iglm_05_31/

That coil will certainly do the job and the price is reasonable.

[stranded-sailor]

Originally Posted by hanleyclifford

Right, voltage at coil+ engine running is where the rubber meets the road. Doesn't matter how you get there. I don't like coils with internal resistance because they do not afford the opportunity to monitor voltage where it matters. The internal resistor may indeed reduce the voltage to an acceptable level but you cannot measure it, and because the resistor is in the coil there will be heat generated. Heat is the enemy of electrical devices, yet ironically most do produce their own heat.

So as I'm trying to figure this out I'm wondering if this coil not having an internal resistor being part of the problem, or causing me a new one. I took old coil to part store and he gave me this new one. Now that I look at it, with the new info I'm gaining here, I'm seeing that it says external resistor required. Has using this coil they gave me caused me more problems due to that?

[stranded-sailor]

Originally Posted by hanleyclifford

That coil will certainly do the job and the price is reasonable.

Thats actually 4$ cheaper than the one I got here and I'm thinking this one is wrong to boot. That's what I get for going to a part store without knowing exactly what I'm looking for!

[stranded-sailor]

Originally Posted by joe_db

1.9 ohms across the coil primary is WAY low. They will burn out. You want around 4 ohms or so.
My coil is about that as-is, but if you don't have one with that much resistance you can either buy a new one that does or add a ballast resistor.
We also have the issue of the electronic ignition itself burning out, which is rare but not impossible.

How would I test to see if the ignition is burnt out?