Pulse generators


Information and questions on GL1500 Goldwings (1988-2000)
  • Sponsored Links
Post Reply
User avatar
bohdan
Posts: 205
Joined: Thu Apr 12, 2012 7:39 am
Location: Venice, Florida
Motorcycle: 1977 GL1000
1977 GL1000
1977 GL1000
1993 GL1500
2013 GL1800
2013 GL 1800 trike
2009 Yamaha

Pulse generators

Post by bohdan » Sun Dec 18, 2016 9:52 pm



Gents, perhaps a layman understanding on these pulse generators. I have a 93 aspy that overnight is difficult to start. It backfires and now I hear a popping out of the carburetor during cranking. After cranking and cranking and cranking.... it starts.......after it starts I can continually start it to no end after I shut it off

So where does that lead? Does the pulse generator the item that fires the spark? I know that it has to wait for a revolution and then fires. Through the ecm and then signals the coils to unload the spark?
Is it possible that the the pulse generators have a malfunction and fire at the wrong time? Maybe ecm has intermittent problems? How do the pulse generators pick up the signal? Magnets? Can anything obstruct this? Mighty obliged with any insight. Cheers
.



User avatar
virgilmobile
Posts: 8552
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Pulse generators

Post by virgilmobile » Mon Dec 19, 2016 8:43 am

First and most important is enough voltage applied to the coils and ECM module.I find that if it drops below 10.5 volts, the ignition gets iffy.
Second..there are two pulse coils up front by the timing belts.They are operated by a trigger wheel.It is not a magnet.The pulse coil has the magnet in it.The trigger wheel upsets the magnetic field creating the pulse.
The pulse coils have 2 separate functions.One counts the triggers and the other watches for the missing tooth.This one determines what coil to fire.
Generally a pulse coil fails with heat.
Personally I'd first look at the voltage at the battery or ECM during first crank.Get it above 11 volts for the most stable spark.

User avatar
bohdan
Posts: 205
Joined: Thu Apr 12, 2012 7:39 am
Location: Venice, Florida
Motorcycle: 1977 GL1000
1977 GL1000
1977 GL1000
1993 GL1500
2013 GL1800
2013 GL 1800 trike
2009 Yamaha

Re: Pulse generators

Post by bohdan » Mon Dec 19, 2016 12:12 pm

Thanks Virgilmobile. Yes, I remember the pulse generators when I did the belts some time ago. Yes, I get the voltage above the mark and above the 11volts when I checked it the last time. Is it possible that if these are in the failing mode, that they maybe creating a "rogue" spark? Igniting when there is fuel in the muffler and the exhaust valve open? the loudnenss of the backfire would definitely implicate that. How frequently does a pulse generator fail? Would there be something that would obstruct each other receiving the magnet signal? Mighty obliged for all your help. n

User avatar
virgilmobile
Posts: 8552
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Pulse generators

Post by virgilmobile » Tue Dec 20, 2016 4:37 pm

Is there any chance that a cam belt is off one tooth?
Might as well scrutinize that while your poking about the pulse coils.
You can measure the pulse coil resistance when cold for factory specs.
The bike would still run but may have trouble when it's cold getting started.
Also the physical positioning of the pulse coil needs to be right around 0.10" (as i recall) from the trigger wheel spikes to the pulse coil metal pin (and clean).

User avatar
bohdan
Posts: 205
Joined: Thu Apr 12, 2012 7:39 am
Location: Venice, Florida
Motorcycle: 1977 GL1000
1977 GL1000
1977 GL1000
1993 GL1500
2013 GL1800
2013 GL 1800 trike
2009 Yamaha

Re: Pulse generators

Post by bohdan » Tue Dec 20, 2016 5:38 pm

Hey Virgilmobile. I don't think it is off with one tooth. Runs like a champ like it always has. Is there adjustment to the pulse generators? I thought it was simply a direct bolt up without slots. Maybe...... Maybe the dirt. Maybe that too. Give it a try this weekend. Cheers

Mighty obliged.

User avatar
virgilmobile
Posts: 8552
Joined: Sun Sep 19, 2010 5:39 pm
Location: Denham Springs,La.
Motorcycle: 1988 GL1500 I
Previously owned
78 GL1000
81 GL1100
82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: Pulse generators

Post by virgilmobile » Tue Dec 20, 2016 7:23 pm

Its been a while sense I've been there. Double check all anyways.Don't assume.



Post Reply