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-   -   Mystery Shutdown (at just the wrong time!) (http://www.sailnet.com/forums/atomic-4/80771-mystery-shutdown-just-wrong-time.html)

JimPendoley 11-14-2011 07:24 PM

Mystery Shutdown (at just the wrong time!)
 
Hi All,
Had a nerve wracking shutdown of my A4 today while sailing in gusty conditions. Symptoms were a "Clunk" and then a stuttering shutdown. Upon restart, I noticed my tach stopped reading. I've converted to an electronic ignition years ago. The engine ran a minute or two then shut down again. Oil pressure fine and so was the temp, alternator charging normally. I was motor sailing in boisterous conditions and a little on my ear. I would have thought it was sediment in the tank stirred up, but I do have a fuel water separator and I add gas stabilizer with every fill. This happened more than half a dozen times and it's a problem today because I have to exit a particularly long and tortured channel in the next few days.
The engine did finally stay running, but I kept the throttle low and the boat flat-still no tach. Is this suggestive of a coil breaking down? Prop seems clear, but I'm not going overboard to check-its November in New England after all...no water int the bilge.
Any suggestions on how to test the coil greatly appreciated.

saillowey 11-14-2011 08:01 PM

Jim:

When I converted my last boat to electronic ignition, I had the same issue, but it happened after about an hour of sailing. I read somewhere that it could have been the coil, and the PO didn't really do much with her. I pulled the coil, and the bottom was rounded out, presumably from the heat of the coil. I replaced the coil, and mounted it to the bulkhead, and had no issues since. I think your coil was newer than mine, perhaps that is why it lasted.

Good Luck!

LakeSuperiorGeezer 11-14-2011 08:46 PM

I could be the coil and you could replace it and see what happens, but I am thinking something in the electronic ignition circuit is defective because of the tachometer issue, if the tach drops out while the engine is still turning over. If you are sure no water is in the fuel, then it almost always comes down to either ignition or fuel starvation. Usually ignition problems cause an instant stoppage. Your stoppage seems a stumbling one with rough running before stopping. So because of this rough running, my other guess is debris in the fuel tank are plugging things up ahead of the filters because the problem occurred in rough weather where the junk in the bottom of the fuel tank are getting into the fuel delivery system. What you need to do is some trouble shooting. Put a fuel pressure gauge after the fuel pump and see if the pressure drops when the engine quits. If you have access to an ignition analyzer, you could try that. Upending a sparkplug in the center of the distributor cap and tying the wire from the coil to it would give a visual indication of a viable spark; however, someone is likely to accuse me of trying to kill you by blowing the boat up if there was any gasoline about in the engine compartment.

tommays 11-15-2011 08:46 AM

What coil did you use as the Pertronix electronic ignition kit requires a coil with and internal resistor or it will damage the unit

JimPendoley 11-15-2011 12:47 PM

Engine shutdown (at just the wrong time!)
 
Hi,Thanks for the replies.

I don't think its bad or dirty fuel because after multiple shutdowns, I managed to start the engine and run in under low power-but still NO TACH. If it was just bad fuel, I'd still have the tach. I have an electric (facet) fuel pump which is in the ignition circuit-wondering if it is failing and drawing too much current thereby damaging part of the ignition circuit?

Could also be the coil failing-gets hot and fail runs after cool down at low power. Why the tach would not run after restart is curious, but wiring could have overheated? Anyone want to tell me an easy test to rule out one or the other? My thinking is it has to be the fuel pump failing (intermittently) or the coil beginning to fail intermittently.

Its a problem because I am in a remote spot anchored and have to exit via a long and shallow estuary.

tommays 11-15-2011 01:33 PM

I cant say for sure if your boat is wired in a standard manner or wile e coyote style which is pretty common in older A4 boats

The tack can be bad and short out the ignition so i would remove the tack wire from the coil to see how it goes

The electric fuel pump SHOULD be wired through and oil pressure switch which would not allow the pump to run without oil pressure BUT that should not affect ignition

At this point i would connect a meter with clips while its runing and see IF your losing power when it stops and work from there

LakeSuperiorGeezer 11-15-2011 02:23 PM

I have seen debris collect in fuel line fittings. The fittings are smaller than the fuel line so junk will collect at fittings and cut off fuel, but then open up enough when flow stops to restart the engine and then fail again very soon on, or maybe hours later. Under low power enough gasoline could get through to run the engine. However, I do not think this is the problem. The non-operational tachometer indicates to me that the triggering circuit is getting weak for the rest of the electronic ignition system. The triggering circuit would also drive the tachometer. It’s probably not the coil but these are cheap so just replace if you think that is it. It might be it. My experience with coils is that when they fail, coming back to life after cool down is unlikely. I do not think the electric pump influences the ignition system because if the current draw were too high to influence it, the fuse or circuit breaker would open. I suppose it could be a resetting circuit breaker that would allow intermittent operation and in that case both fuel pressure and ignition would not be there, but it takes a number of minutes for an automatic reset because of required cool down. If the water is deep enough at your dock, you could tie the boat securely and run the engine in gear for test purposes. Else, borrow an outboard in case the engine quits in a bad place.

RobGallagher 11-15-2011 02:47 PM

While there are several possible causes, most of them relative easy fixes, my advice to you would be to visit Moyer Marine's forums and website. There is a treasure trove of information there. You could even call them as Don or his son often answer the phones an seem to love to talk A-4.

Not to say you won't get great advice here...

JimPendoley 11-15-2011 03:39 PM

Thanks everyone. Rob, I did go to Moyer site, very familiar with them-but there is a delay between when you join and when you can post. Engine starts normally now, but still no tach. Reading the Moyer forum, there is a thread about Facett fuel pumps failing gradually and the fuse not blowing, but the wiring heating up and creating a soldering effect that will take out the ignition circuit. Well, right now my engine seems to run reliably, but the tach is dead. I think I'll disconnect the tach in case it was shorting to the coil and interrupting the circuit. Any other insights greatly appreciated.
Jim

LakeSuperiorGeezer 11-15-2011 07:15 PM

Whether you decide to to any testing or not, keep a good anchor ready going through that long and tortured channel you mentioned. If you decide to do some testing, buy a vacuum and fuel pressure tester that measures to about 10 PSI and vacuum to 30 inches mercury. This is not for fuel injection pressure measurements, which are ten times what this gauge measures. This tester is for engines with carburetors. The vacuum tester can be used for setting up low idle jet, just adjust jet for maximum RPM while adling. Be sure to clamp all fittings as you do not want gasoline in the bilge. The pressure gauge should read about 3.5 PSI for a good fuel pump. I prefer engine driven mechanical pumps as I think they are more reliable than electric.

Ignition spark tester goes inline between spark coil and distributor. It flashes when there is a spark. If no spark that really narrows the problem down to the electronic ignition system.

You can search online for these items.


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