pulse generators


Information and questions on GL1500 Goldwings (1988-2000)
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Thesseus
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Location: Thorold, Ontario, Canada
Motorcycle: 1988 gl 1500

pulse generators

Postby Thesseus » Wed May 09, 2012 11:32 am



Testing pulse generators, how does one go about it to check for failures, having miss firing problems



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WingAdmin
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Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
1989 PC800 (wife's!)
1998 XV250 Virago (sold)
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Re: pulse generators

Postby WingAdmin » Wed May 09, 2012 12:05 pm

You can check them easily without pulling the timing belt covers off:

Pulse Generator Check
Pulse Generator Check

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virgilmobile
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Re: pulse generators

Postby virgilmobile » Wed May 09, 2012 1:09 pm

I've not looked into the "magic" of the ignition system on the 1500 too deep.
It's different in that it uses 2 pulse generators on the crank and no cam angle sensor that I can identify.It's still a mystery to me how,with 2 pulse coils it can determine when to fire 3 coils and do it at the right time :?: It must be something with the number of pulses on one(the primary) and timing it against the offset pulse coil(position sensor).

Ya know,this is gonna take a BUNCH of coffee.

Oh,by the way,Misfiring can be attributed to failing vacuum lines.This bike has a bunch of them and the carbs use a vacuum operated electronically controlled system.Take a gander at this post while your reading.There's a few links near the end.

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WingAdmin
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Re: pulse generators

Postby WingAdmin » Wed May 09, 2012 1:53 pm

virgilmobile wrote:I've not looked into the "magic" of the ignition system on the 1500 too deep.
It's different in that it uses 2 pulse generators on the crank and no cam angle sensor that I can identify.It's still a mystery to me how,with 2 pulse coils it can determine when to fire 3 coils and do it at the right time :?: It must be something with the number of pulses on one(the primary) and timing it against the offset pulse coil(position sensor).


But that still doesn't tell it what the cam position is - regardless of its method of determining crank angle, that can't possibly tell it what the cam angles are - they could be 180 degrees off, and it wouldn't know.

I looked at the schematic, and there are no other sensors hooked up to the ECM. So...I don't know. It's magic.

More likely, it's just a bunch of complex math. :)

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virgilmobile
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Re: pulse generators

Postby virgilmobile » Thu May 10, 2012 3:24 pm

It is math magic,and a bit of design.
I found that the timing wheel has evenly spaced tabs that trigger the pulse coils.
However there is one tooth not there.It's a 11 tooth wheel.
I guess the ECU uses the missing pulse compared to how many pulses the second one gets to determine which coil to fire.
This explains the delayed spark.The engine has to roll the empty slot past both the pulse coils before it can calculate when to fire the coil.
I'm not going to calculate crankshaft angle,compared to pulse coil positions compared to the missing pulse signals today...Probably not in the near future either :)
Suffice it to say,it works.....Now to trick the ECU to change the timing with altering the temp sensor resistance :mrgreen:

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WingAdmin
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Posts: 17045
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Motorcycle: 2000 GL1500 SE
1982 GL1100A Aspencade (sold)
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1998 XV250 Virago (sold)
2007 Aspen Sentry Trailer

Re: pulse generators

Postby WingAdmin » Thu May 10, 2012 3:38 pm

Aha. Makes perfect sense. That explains why my 1100 springs to life pretty much the absolute instant I touch the starter, whereas my 1500 has to crank a couple of revolutions before it fires.

Thesseus
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Re: pulse generators

Postby Thesseus » Thu May 10, 2012 8:34 pm

The Pulse Generators are ok and up to specs after checking. With a timing light on each spark you can see a miss in every cylinder. A thurough review of the timing belts is next but the evidence is leading to a bad ECM unit. A spray test of the hoses are coming up also, but with a lot of visual checking they seem ok. However the spark plug wires are getting stiff so an replacement of those are coming up. There is no arcing noticible but while it is apart..... All components that has been the problem on some bikes are ok. Any hoses that have a 90 degree bend will be replaced. The saga continues. Have received a lot of great advice from the Forum. Thanks.

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virgilmobile
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Re: pulse generators

Postby virgilmobile » Thu May 10, 2012 9:05 pm

Before you condem the ECM . Use a DVM and measure the DC voltage on the main power right at the plug to the ECM using it's green wire for the meters ground. You want to see at least 12.8 volts going into the switched power lead when the bike is running.Remember, this is a computer module and it really gets questionable if the volts drop below 11.8 volts.also the volts that feed the ECM is fed not only from the ignition switch,it also has to go back to a relay,all the way to the kill switch and then down to the ECM.I improved the low volts on my 88 by using a switched relay to power the ECM and coils direct from the battery.I end up with no voltage loss in the wiring or switches and a rock solid ignition system.keep testing.It would be nice to see a video of the spark.I posted one a while back on mine.It was something like "88 gl1500 ignition problem".look in the search section.If you want to try something,you could watch the spark and jump a battery hot wire direct to the switched ignition wire on the ECM to see if it improves.Ask if you need details or I lost you.

Thesseus
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Re: pulse generators

Postby Thesseus » Fri May 11, 2012 6:34 am

Thanks for the info. The current flow is as it should be, but as you say if there is a loss of voltage at the ECM it may cause the problem. Will also check alternator flow since it now considered old and the battery, YUSA is in its 4th year that I know of. Thanks again.

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virgilmobile
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83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: pulse generators

Postby virgilmobile » Fri May 11, 2012 9:58 am

When you measure the volts,measure at the plug on the ECM. Probe into the hot wire AND the ground wire that go into the module to get the reading.
Never assume that a ground wire is actually perfectly grounded.
I have seen voltage drop due to a corroded crimp connection.

willemb
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Re: pulse generators

Postby willemb » Wed May 22, 2013 11:21 am

Could I accidently installed my pulse generators wrongly after timing belt changes. I now have a missfire allthough the timing marks linesup 100%

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virgilmobile
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78 GL1000
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82 GL1100 I
83 GL1100 I
83 GL1100 standard
84 GL 1200 I

Re: pulse generators

Postby virgilmobile » Wed May 22, 2013 12:08 pm

willemb wrote:Could I accidently installed my pulse generators wrongly after timing belt changes. I now have a missfire allthough the timing marks linesup 100%


You could inspect them again for placement and end gap,but as I recall,there are no adjustments on the pulse coil mounting ,it's just bolt them back on...
Is there is a chance that the timing belts were installed wrong...Perhaps one tooth off???
Did the bike run perfectly before you replaced the belts?

willemb
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Location: Gobabis,Omaheke,Namibia
Motorcycle: 1995 GL1500 Aspencade

Re: pulse generators

Postby willemb » Wed May 22, 2013 2:55 pm

Thanks for the responce. On rechecking and checking after the new belts were on the timing is spot on. The bike ran smoothly before the change. This afternoon I loosened the top generator and then just titened the bolts again. After this pocedure the engine was very irregular and missed even more. It also backfired more. What do you mean by "check the gap"

I cannot find any photos on the internet which can show me how to position the generators. Both have wires attached and it seems obvious the wires would be placed facing away from the Ignition Pulse Rotor. Where is the following fiiting. 4P-WHT. According to the Honda manual you must conect this fitting during the process of installing new belts. If it is the wiring plug conected to the right radiator fan, I have run the bike (perfectly) without it being conected as I removed that specific fan for another reason.
Thanks for interest in this matter.

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virgilmobile
Posts: 7646
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

Postby virgilmobile » Wed May 22, 2013 3:43 pm

The "4P-WHT" connector is the 4 wires to the pulse coil.The bike will not run if unplugged.
The pulse coil....It has a magnet in it and can attract bits of metal....Be certain that the exposed piece of metal is clean...
When assembled,I suspect that there should be just a small gap between the trigger wheel tooth and the exposed metal of the pulse coil...As I remember it is near 0.010"....If it's too far away the pulse coil won't 'pulse' very well.

There are 2 pulse coils...one pulses the ignition and the other determines which coil fires.

Here's a picture similar to what you have.It's not exactly the same but should give you the idea of how it works.
One other thing to mention too....I know for a fact that if the battery voltage is low,the bike will have a problem running....Check to see if the battery is above 13 volts while running.
My 1500 will not run the ingition system if the battery volts fall below 10 volts.

willemb
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Location: Gobabis,Omaheke,Namibia
Motorcycle: 1995 GL1500 Aspencade

Re: pulse generators

Postby willemb » Thu May 23, 2013 5:00 am

Huraaaaaaaaah. Halleluja. I did did did did did it. So stupid O so stupid. Shes up and purring like the beast she is. I swapped the nr 2 and nr 4 plug wires.

Thanks to all

Wing Love

WIllem




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