Pulse Generators?......maybe?


Information and questions on GL1200 Goldwings (1984-1987)
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julimike54
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Pulse Generators?......maybe?

Postby julimike54 » Thu Oct 01, 2015 8:04 am



I'm trying to find the cause of a very short series of engine stopping on the '86 GL1200a. During a 5 day trip wandering NW Ark., on day 3 was riding through all the wonderful mountain roads and all of a sudden for less than a second the engine died (about 50mph, 5th gear going up hill out of curve) then refired & rode further. Over the next hour this repeated in verying lengths of time, the worst was long enough that I pulled in clutch, oil light lite and released clutch, it refired. Things I noticed when this occured were, most notable rpm dropped to zero even coasting in gear, every time I looked, no other electical symptoms appeared (ie lights stayed on, dash functioning, etc.). Once on a refire a loud pop eminated from the pipes. Most times the stoppage was less than a second & it allways refired. We stopped for a break (15 - 20 min.), looked over bike & saw nothing unusual. Wife talked to bike, haha. After that stop and for the rest of the 1100 mile trip it never did it again. I'm wondering if the key is the rpm drop to zero every time? Would that indicatre the pulse genrators stopped functioning & the cpu didn't know what to show on rpm and couldn't of course fire sparks?

Any ideas?
Mike


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virgilmobile
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Re: Pulse Generators?......maybe?

Postby virgilmobile » Thu Oct 01, 2015 9:10 am

Great observations.The tach is driven by spark.Kinda.
A sudden and intermittent death of spark can be caused by a couple of problems.
If the pulse coil quits,no spark,no tach.
Another is loss of electric feeding the ignition.Either a intermittent kill switch or broken wire around the steering area harness.
I'd first look at the 4 wire plug from the pulse coil.scrutinize the connections for any corrosion.I just bumped mine and killed the engine.
Second is to remove the kill switch and clean its contacts.
Check the connections feeding the ignition module and the ground lugs that have green wires attached.
Some have also found a bad ignition switch,connections at it corroded.
Usually when a pulse coil fails,it will go "thermal"..at a certain temperature,they will open up and usually take a bit of time to start working again.Being that yours cut on and off quick,I'm leaning more toward a intermittent connection.

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julimike54
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Re: Pulse Generators?......maybe?

Postby julimike54 » Fri Oct 02, 2015 8:14 am

Thank you for the reply. Yesterday I thought about your Kill switch comment. Rode it around the block & sure enough if I wiggled the Kill switch a little, could replicate the problem (ie RPM drop to zero & engine dies, in fact I almost had to push it home, more wiggling & got it going again), So I guess I need to take the Kill switch apart & clean it up. Any tips or tricks (pics?) of doing this?
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virgilmobile
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Re: Pulse Generators?......maybe?

Postby virgilmobile » Fri Oct 02, 2015 8:23 am

I've done a few.Each one successful.
Slowly disassemble it.Theres a spring in there.
I use a fine large flat file to resurface the baseplate and its brass contact area.Some fine sandpaper on the shorting bar.
A touch of grease on the pivot points.None on the contacts.
A dab of grease on the spring to hold it and the bar steady till you get it assembled.
If needed,some will stretch the spring just a touch for a firmer contact.
If everything should "go bad"...don't panic.Just short the 2 wires together on the switch to keep it running till you get another switch.

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julimike54
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Re: Pulse Generators?......maybe?

Postby julimike54 » Sat Oct 03, 2015 6:24 am

Just a follow up....took Kill switch apart, cleaned contacts (used a finger nail polishing stick, has 4 different grits for shining nails), stretched the springs slightly, put back together, all good. No amount of fiddling with the switch will cause it to die, except when you turn it to Off! Thanks for insights.
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Riding anything is a good day!
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virgilmobile
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Re: Pulse Generators?......maybe?

Postby virgilmobile » Sat Oct 03, 2015 8:00 am

Ill bet you didn't take pictures either...didja :roll:

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julimike54
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Re: Pulse Generators?......maybe?

Postby julimike54 » Mon Oct 05, 2015 5:02 pm

No, I thought about it but, six screws later & a c-clip it was apart. I was also under a deadline (wanted to ride) & didn't know if it would be broken in there. So the three screws that hold top & bottom together; 1 screw holding wire retention plate; 2 screws for the 2 wires & the switch will fall out of the upper housing, keep hand under top of switch. Carefully compress switch slightly; remove clip & slowly ease up on bottom 1/2 of switch. Inside is a ball on a spring (that's for the detent feel of switch), cleaned & slight stretch to spring, makes it a little more positive feel. Remove the contact bar, clean, same with contacts on bottom 1/2 of switch; slight stretching of the 2 springs under the bar. Light coating of di-electric grease on contacts. Re-assemble, biggest pain in putting back together is starting the first wire screw (because you have to hold housing, switch, wire & screw, thank you better half, third hand)
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DCoop44
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Re: Pulse Generators?......maybe?

Postby DCoop44 » Sat Apr 16, 2016 1:04 am

Virgilmobile,

You wrote: "Usually when a pulse coil fails,it will go "thermal"..at a certain temperature,they will open up and usually take a bit of time to start working again.Being that yours cut on and off quick,I'm leaning more toward a intermittent connection."

I'm having a problem with my '84 Aspencade that is heat related. The engine dies while all electrics continue to work properly. After sitting for 10-20 minutes the engine fires up and runs normal. There is much more to describe the problem but my question today is about your use of "pulse coil". Are you describing the pulse generators but using "coil" instead? I'm not familiar with a pulse coil but would like to know about them as I try to find what is causing this intermittent, heat related engine shut down. This NEVER has happened in cold weather, only when it's warmer. I appreciate any info you can pass on.

I've replaced the ECI with a known good one, and tomorrow switching out the ignition coils for good running ones. Also I'm wondering about the fuel pump, it seems to be abnormally hot when I have these shut downs. I mean too hot to keep your fingers on more than a second without being burned.

Thanks in advance,
D C

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virgilmobile
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83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Pulse Generators?......maybe?

Postby virgilmobile » Sun Apr 17, 2016 5:06 pm

Different wording,same function.
This part generates a small pulse used by the ignition module to produce a spark.
I refer to it as a pulse coil because it is a coil of fine wire wrapped around a magnetized core.There are electronic type pulse generators using no coils but produce the same results.One of these is the electronic speedometer sending unit.




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