Strange spark problem on 2001


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Strange spark problem on 2001

Postby WingAdmin » Sun Jan 05, 2014 9:20 pm



I had someone with a 2001 GL1800 ask me a question the other day, and it's a bit of a head-scratcher.

He has very weak spark on all the left-hand cylinders, but strong spark on all the right-hand cylinders. The plugs on the left side often don't have enough spark to ignite the mixture, and will be wet with gas. Testing against the engine block, the right side plugs have a very strong, bright spark that leaps a large gap, the left side plugs have a weak spark that will only leap a very small gap. Testing against a known good ground (i.e. from wire connected to battery ground) shows the same results.

He has had all three coils, all plug wires, and all plugs replaced, with no change at all.

Looking at the circuit, each coil has three wires: a +12V, a ground, and a wire that goes to the ECM, which I assume (if it works the same as other Wings) that it momentarily grounds to allow current to flow.

GL1800 Ignition Circuit
GL1800 Ignition Circuit


The previous Goldwings have two wires to each coil, as shown in this GL1500 circuit excerpt:

GL1500 Coils
GL1500 Coils


They have one constant +12V line, and the ECM pulses the other wires to ground, to move current in the primary of the coil and induce current in the secondary.

So what is the extra ground on each GL1800 coil for? And does anyone have an idea what could be causing half of each coil to produce a weak spark? Without knowing what's going on inside those coils with the third wire, I can't really start to make a guess.



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virgilmobile
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Re: Strange spark problem on 2001

Postby virgilmobile » Mon Jan 06, 2014 11:50 am

Only a guess about the third wire...
2 possibilities...
least likely is a RF shield ground....

Most likely is a center tap secondary ground...Kinda like 2 secondaries with a common primary.
this would eliminate the odd spark wear from reverse current flow across the gap...both plugs on one coil would conduct from the engine to the coil..

Because it has a common problem to all 3 coils,I'd look for a common connection...

The only thing I can suggest is to supply the coils with a external 12 volt supply..Let the coils absorb as much power as they need (seperate from the bikes wiring)to fire both plugs...

Also verify the coil does have a good ground..

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Re: Strange spark problem on 2001

Postby WingAdmin » Mon Jan 06, 2014 8:01 pm

virgilmobile wrote:Only a guess about the third wire...
2 possibilities...
least likely is a RF shield ground....

Most likely is a center tap secondary ground...Kinda like 2 secondaries with a common primary.
this would eliminate the odd spark wear from reverse current flow across the gap...both plugs on one coil would conduct from the engine to the coil..

Because it has a common problem to all 3 coils,I'd look for a common connection...

The only thing I can suggest is to supply the coils with a external 12 volt supply..Let the coils absorb as much power as they need (seperate from the bikes wiring)to fire both plugs...

Also verify the coil does have a good ground..


I thought of RF shield as well.

If it's a center tap secondary...then what is the ECM doing to trigger, being that there is constant +12V, and the ECM switching ground to initiate pulses?

My thinking is exactly the same as yours. I haven't had my hands on it, but I think I am going to suggest he measure potential between the coil +12V and battery +12V, then coil ground and battery ground, see if there is something there. However, even if it's down a couple volts, it should be affecting plugs on both sides equally, assuming the coils are just a single primary and single secondary.

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bluewing2010
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Re: Strange spark problem on 2001

Postby bluewing2010 » Mon Jan 06, 2014 8:10 pm

An educated guess is the common earth going to all 3 coils has a dodgy connection. On the drawing it's the green wire. My reasoning is that in this configuration, the spark plugs are fired in series, with the cylinder head being the common connection between the two plugs. If the earth connection to the coils is dodgy, the plugs on one bank will be getting their earth connection through the heads, but the other bank will have a crook earth through the coils. I haven't got a clue where you would physically look for this earth connection, but I reckon that's the problem.
Hope this is of help.

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Re: Strange spark problem on 2001

Postby Fatwing Chris » Mon Jan 06, 2014 8:56 pm

There was a guy on the SS site that had a similar issue and it ended up being rubbed though wires on the right hand side just around the rad area.I'll see if I can find the thread and post a link.
If I'da known it would last this long,I'da taken better care of it.
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Re: Strange spark problem on 2001

Postby Fatwing Chris » Mon Jan 06, 2014 10:15 pm

Here's the link.Not the exact problem,but might be worth a read.http://www.goldwingfacts.com/forums/2-g ... ilure.html
If I'da known it would last this long,I'da taken better care of it.
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virgilmobile
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Re: Strange spark problem on 2001

Postby virgilmobile » Mon Jan 06, 2014 11:03 pm

I guess If someone wanted to find out,pull one plug wire loose and measure to ground.
If there is no resistance,it's a single secondary winding.Measure a good bike obviously. :mrgreen:
Considering that one side is weak,make sense If it's a dual wound secondary.As the field collapses ,a weak pulse would be absorbed into the winding closest to the primary.The weak side may simply be the outer secondary winding.
Either a weak pulse field collapse or a bad winding ground.




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