#1
IP: 148.170.241.1
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Short? Or bad component preventing engine from shutting off?
Some people have trouble getting their engine to run or keeping it running. I have the opposite problem - getting it to shut down.
I have what I was told is a 1983 Atomic 4 in my 1968 Pearson Wanderer 30. On the switch panel inside the companionway, there is a keyed switch that closes the ignition circuit. Up in the cockpit there is a push-button momentary switch to start the engine. To start the engine, you turn the key, which only closes the circuit (but does not start the engine). Then you hold down the little spring-loaded button to spin the starter and kick the engine over. As soon as it starts, let go of the push button and the engine runs. To turn the engine off, you just turn the key, which opens the circuit. At least that's how it's supposed to work. A few weeks ago, I pulled up to the slip after motoring for about an hour, reached in and turned the key off, and the engine just kept running without any change whatsoever. The engine just completely ignored the switch. I turned the key back and forth with no effect. I left the key in the off position and stood there scratching my head trying to figure out what to do next, when after a couple minutes, the engine finally sputtered and died. I assumed the keyed switch was bad, so I replaced it. I now know that was about $26 wasted, because it made no difference whatsoever and it still does the same thing. I've been using the choke to kill the engine. Last weekend, I was out sailing, and after I raised the sails, I turned the key off to try to shut off the motor, with no effect, so I choked the engine to kill it. Later, at the end of the day, I started the engine up without realizing the key switch was still in the off position. Altough the key was off, the engine started and ran just fine, but after about three minutes it started sputtering and slowing and then died. We were coasting along and I was saying two words, the first of which was "Oh..." when I suddenly realized the switch was off. I reached in, turned it back on and restarted the motor without incident. When we got back to the dock, once again, I had to choke the engine to kill it because turning off the key had no effect. So that tells me that either (1) there is an intermittent short somewhere in between the keyed switch and the ignition that is completing the circuit and thereby bypassing the switch or (2) there is some other component that is "sticky" - that is, it stays closed when it's supposed to open. Maybe a solenoid of some sort? The previous owner replaced the original ignition with an electronic ignition system. I plan on taking a good look at the wiring diagrams I have available - I took a quick look at the wires this weekend, but I didn't have time to fully trace them out. Any ideas as to what the issue could be? Thanks in advance.
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- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#2
IP: 71.118.13.238
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Hmm??
Bill, check the wiring on the coil, you may have something feeding back through another circuit that is about to fail itself.
Do check the schematics and nothing but ign related wiring should be on the coil. Dave Neptune |
#3
IP: 24.224.206.117
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Dave,
I like your suggestion. Sounds really familier although I just can't recall what the cause was. |
#4
IP: 71.118.13.238
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Shut off???
Maurice, sometimes the "exiting" line for the field of the alternator can feed back to the ignition circuit depending on the wiring and that may be it.
Worth a check. Dave Neptune |
#5
IP: 24.224.206.117
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Hi Dave
I really can't recall, I know my neighbor and I finally installed a push/pull ignition switch and a push button for the starter...no key anymore. I hope Bill T gets it sorted out without too much difficulty. |
#6
IP: 148.170.16.104
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Thanks. I'll try to check it out next weekend. The wierd thing is it was working just fine and then all of a sudden started doing this.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#7
IP: 24.152.131.220
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Unless you've been shutting off your battery switch after choking the engine you may have subjected the coil to some bad ju-ju, electronic ignition too.
__________________
Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#8
IP: 161.213.49.1
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Engine Won't Quit!
Disconnect the wire from the key at the coil. Run a wire from the big battery connection on the starter motor (or the battery itself if access is easier) to the coil, start the engine and see what happens (this bypasses the boat's wiring). Don't leave the hot jumper wire on the coil for any length of time when the engine isn't running.
Disconnect the wire to any other devices that are wired to the coil one at a time (fuel pump, alternator) and temporally power them with the hot jumper wire to see if the problem goes away. TRUE GRIT |
#9
IP: 148.170.241.1
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Quote:
Thanks!
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#10
IP: 148.170.241.1
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Quote:
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#11
IP: 24.152.131.220
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Elucidate? Oh-oh, looks like another word of the week contest might be brewing.
Since turning off the key didn't stop the engine it follows that the coil remained energized. Leaving the coil and/or electronic ignition module energized without the engine running cooks them internally over time. Turning off the battery switch should have de-energized the system and avoided the risk of damage. I'm not saying your components are damaged, just mentioning the possibility.
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Neil 1977 Catalina 30 San Pedro, California prior boats 1987 Westsail 32, 1970 Catalina 22 Had my hands in a few others |
#12
IP: 71.231.70.209
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Bill,
Look at the coil and one by one disconnect any accessories connected to it, hour meter, tach, anything else, etc. Disconnect a wire, and shut the ignition switch, if no change, disconnect another accessory wire and shut the ignition switch off, and on and on. You can try the same thing with any accessories connected to the ignition terminal of the ignition switch as well. You may stumble into the circuit that is causing the short. Mark C27 "Solution" |
#13
IP: 142.68.240.102
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I suspect Neil meant that even though you stop the engine by pulling out the choke, there is still hot current flowing in the ignition circuit where it should not, owing to the short that has developed. If you have an electronic ignition module, it can be damaged by having electricity applied to it when the engine is not running normally. That's only one example of problems that can occur.
__________________
1974 C&C 27 |
#14
IP: 71.168.64.77
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I am wondering if it is safe to leave the key on for up to 5 minutes?
For example when testing fuel pumps, safety switches and other spark related testing etc? |
#15
IP: 173.166.26.241
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Art - The ignition circuit should never be energized even for a few seconds unless you intend to start the engine. This thread is a good recommendation for color coding of wiring (I use purple for ignition circuit). All of the above are solid trouble shooting ideas and in fact this should result in a rewire of the boat in question. A live circuit of unknown origin is intolerable in any engine driven device. Regards, Hanley
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#16
IP: 199.173.224.31
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Easy test:
Start the engine and let it run a bit. Turn the key off. If it still runs, remove the wire that goes from the coil to the distributor. If the engine quits, you still have power going to the coil. If it still runs, it is dieseling ("running on"). Cars back in the mod 70s would do this. I think it is usually caused by excessive carbon buildup. Something ends up getting hot enough to ignite the fuel/air mixture without a spark. |
#17
IP: 148.170.241.1
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It's definitely not run-on. I had a 1977 Chevy that did that, and I know what that's like. An engine running-on sputters and shudders and clunks and then finally dies.
I'm confident this is the coil remaining energized, because the engine just continues to run perfectly normally, as if I never switched the switch off at all.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#18
IP: 199.173.224.31
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I have had the key switch go bad in airplanes and refuse to shut the engine off. Since we usually cut the fuel to shut down, this can be quite dangerous because you might not know it happened until someone moves the prop
Quote:
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#19
IP: 148.170.241.1
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See above - I have already replaced the key switch, to no effect.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#20
IP: 199.173.224.31
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Do you have ANY other connection to the + side of the coil other than one wire direct from key to coil?
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#21
IP: 148.170.241.1
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That's what I need to check out, which I plan on doing this weekend. I have not yet taken a good look at what's connected to the coil.
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
#22
IP: 199.173.224.31
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On my boat there is another wire that goes to the voltage regulator. It turns the field current off when the engine is not running. If my regulator became defective and fed current back down that wire to the coil, the engine would not shut off.
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#23
IP: 161.213.49.1
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Engine Won't Quit - Part Two
If the problem is wiring related and you have a wiring harness or plugs in the circuit between the key and the coil pull them apart and check for moisture or water that might be causing a short in the plug(s).
If there is a boat wiring problem you should be able to get normal operation by running a bypass wire from the key to the coil. This should be diagnostic. YOU SHOULD HAVE THE BATTERY DISCONNECTED OR THE CIRCUIT BREAKER OFF AT ALL TIMES EXCEPT WHEN YOU ARE WORKING ON THE BOAT AND GET THIS PROBLEM SOLVED. IF YOU DO HAVE A SHORT AND THE SHORT SEES GROUND YOU WILL HAVE A DISASTER. TRUE GRIT |
#24
IP: 148.170.241.1
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Well it seems - for now, at least - that I "fixed" it.
I started tracing wires from the coil to see what went where and ended up sticking my head behind various bulkheads and spaces and finding miles of wire. The boat is 42 years old and I am at least the fourth, if not fifth, owner. Considering how simple and spartan the boat is, I'm suprised how much wiring there is all over the damn place. Anyhow, while carefully investigating the wiring all around the engine, I discovered that one of the spade lugs on a wire connected to the electric fuel pump seemed to very, very close to , if not touching, a metal fitting. That wire provides power to the electric fuel pump by coming off the coil. So I thought maybe I was getting a short there. I gently bent the spade lug to move it away from the fitting. There was no sign of arcing or anything, though, so I really don't know if that was the case. I also found a couple terminals that were just slightly loose, so I snugged them up. I then found wire with a spade lug on the end hanging free, near the alternator. So now I'm thinking, oh great - was this supposed to be connected to something and it came off? Or is it just an old wire that someone disconnected but never pulled out. Well it turned to be an abandoned circuit that never was pulled out. I think it was for powering an old radio or Loran or something. Anyhow, the fun part is that it was one wire of a three-wire cable. The other two wires were STILL CONNECTED to the batteries! The other end of the cable was just cut off and lying on a shelf. I of course disconnected and pulled them all out. I think it might - might - have been possible that that abandoned circuit was causing an intermittent short. Anyhow, when I tried the key, it worked perfectly. Yesterday I took the boat out with some friends, and at the end of the day, when we motored back in to the dock, I turned the key and the engine shut off as it's supposed to. So - either one of the things I did actually fixed the problem, or just the fact that I dug around in there and wiggled various wires all over the engine might have done it. The question is whether it will start doing it again. Which I will have to see. Next up: replace the leaking head gasket!
__________________
- Bill T. - Richmond, VA Relentless pursuer of lost causes |
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