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Discussion Starter #1
Doing a repair and update on a New to me X. Bike is missing on the Front cylinder. In an attempt to resolve the issueI have replaced all plugs (DENSO IK 16 5303).... pulled the plug wires and exposed new inner conductor on the spark plug boot side... the issue remains. Additionally in the process of doing an oil change, I noticed the oil smelled slightly of gas...... anyone have additional input?


Thanks
 

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Like Chuck said. Check the link for the FPR. It tells you how to test it. Also take a good look at your vacuum hoses. If the hose to your FPR looks these (like mine did) the FPR isn't doing its proper job even if it's been replaced.


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Discussion Starter #5
Like Chuck said. Check the link for the FPR. It tells you how to test it. Also take a good look at your vacuum hoses. If the hose to your FPR looks these (like mine did) the FPR isn't doing its proper job even if it's been replaced.


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Checked the FPR as per the link.... pulled the Vacuum line no fuel present. Turned the fuel pump on .... I
no fuel coming from the vacuum port. According to the tests the FPR is good. However the vacuum lines are old and could stand to be replaced.

I
 

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With the tank off check the two wires off the coil being very careful to look for broken and rubbed insulation. My 06 rubbed through and grounded out as they left the main harness.
 

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Discussion Starter #7
With the tank off check the two wires off the coil being very careful to look for broken and rubbed insulation. My 06 rubbed through and grounded out as they left the main harness.

I will check that in the AM. When this began...I also noticed an increase in the engine noise. When this began...this noise comes and goes. Seemingly from the cylinder that is misfiring.

I attached a short video with audio. Again this noise began when the missing began and does come and go.
 

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spark plug wire to plug cap.. is removable.. and can burn at that point..


unscrew the spark plug cap from the spark plug wire.. inspect.....
 

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Discussion Starter #9
I will check that in the AM. When this began...I also noticed an increase in the engine noise. When this began...this noise comes and goes. Seemingly from the cylinder that is misfiring.

I attached a short video with audio. Again this noise began when the missing began and does come and go.

Good Morning, I pulled all plug wires... checked the Condition of the inner conductor and actually trimmed and exposed anew portion of the conductor. I had a second Vtx 1800. I pulled the front coil pack and exchanged it. The issue remains unaffected.

I also checked the wiring to the coil as suggested. I find no exposed wires or damaged jackets that might cause the signal to ground out.

I am beginning to believe that the bike may have a mechanical issue. Unfortunately I am unable to post an audio file to this site. When I ride, I wear a helmet with Bluetooth music...accordingly I am not as familiar with the Engine noise as I should be...however I am fairly certain the noise is not normal.

I will post the video with audio on FB... the only way I know to share it....

https://www.facebook.com/profile.php?id=100002147414607
 

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what do the spark plugs look like...

injector issues..
wiring for injectors.
do the coil/spark plug "spark" with them out of the bike.. test for spark

if spark.. its injector/fuel.. issue.

need to eliminate known good

air into cylinder
spark
fuel
compression.
exhaust

the basics... for an engine to run.
 

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I listened to your audio, it is muted.
I hear a recurring sound which is probably the de-compressor exhaust lobe.

When you pull the spark plugs and lay the shell of the spark plug on the cyl head do you see sparks at the gap when the engine is cranking????

Valkrider mentioned rubbing of insulation caused a coil wire to be Grounded.
If the Yellow/Blue or Blue/Yellow are grounded the coil is ON but a spark is only produced when the ECM releases a Ground.
Ground is the trigger, false ground from a short, true ground from a ECM, This scenario also has happened with Injectors.
Other times the ECM side (Trigger) has been grounded by shorting on a harness clip at the breakout at the Injector wires.

There have been a few cases where wires have shorted. A few times the the Black/White wire was shorted and blew the 30 amp FI fuse.
Remove the ECM connectors look for the wires going to the IGN coils(Yellow/Blue or Blue/Yellow) and the Injectors(Pink/Blue or Pink/Yellow)

With IGN switch ON, verify +12v on Black/White wires, then pulse a Ground on each Ignition coil and Injector.
You should see an arc at the spark plug, you should hear the injector click when energized.

Do both cylinders, all spark plugs out and shell Grounded.
NOTE:: When the Black/White wire has +12v on it, each coil and Injector will have that voltage on the ECM wire.
That is the first test for continuity through the coil or injector.

Do you have any FI error codes from the FI indicator?

What is the Autolite spark plug you are using???

Do you have a Service Manual??
 

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Discussion Starter #12
what do the spark plugs look like...

injector issues..
wiring for injectors.
do the coil/spark plug "spark" with them out of the bike.. test for spark

if spark.. its injector/fuel.. issue.

need to eliminate known good

air into cylinder
spark
fuel
compression.
exhaust

the basics... for an engine to run

Spark present when plug removed....pics of plugs attached.
 

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Discussion Starter #13
I listened to your audio, it is muted.
I hear a recurring sound which is probably the de-compressor exhaust lobe.

When you pull the spark plugs and lay the shell of the spark plug on the cyl head do you see sparks at the gap when the engine is cranking????

Valkrider mentioned rubbing of insulation caused a coil wire to be Grounded.
If the Yellow/Blue or Blue/Yellow are grounded the coil is ON but a spark is only produced when the ECM releases a Ground.
Ground is the trigger, false ground from a short, true ground from a ECM, This scenario also has happened with Injectors.
Other times the ECM side (Trigger) has been grounded by shorting on a harness clip at the breakout at the Injector wires.

There have been a few cases where wires have shorted. A few times the the Black/White wire was shorted and blew the 30 amp FI fuse.
Remove the ECM connectors look for the wires going to the IGN coils(Yellow/Blue or Blue/Yellow) and the Injectors(Pink/Blue or Pink/Yellow)

With IGN switch ON, verify +12v on Black/White wires, then pulse a Ground on each Ignition coil and Injector.
You should see an arc at the spark plug, you should hear the injector click when energized.

Do both cylinders, all spark plugs out and shell Grounded.
NOTE:: When the Black/White wire has +12v on it, each coil and Injector will have that voltage on the ECM wire.
That is the first test for continuity through the coil or injector.

Do you have any FI error codes from the FI indicator?

What is the Autolite spark plug you are using???

Do you have a Service Manual??


Put plugs on cylinder head all 4.... each plug fires when Engine is turned over.
Additionally the bike fired up and ran flawlessly for 5 minutes... the additional engine noise was gone... no misfires.... then after 5 minutes or so...Engine noise returned and it began to misfire?

No codes at all. Specifically no FI codes.
I replaced the original auto lite plugs with DENSO IRIDIUM PLUGS IK 16 5303.

I am downloading a service manual, currently.
 

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Discussion Starter #14
Okay, latest update .... on black wire with white tracer out of the ECM... there is 12vdc with the ignition on. With the ignition on there is also 12 vbc on the pink wire with blue tracer and also on the pink wire with the yellow tracer. Momentary short to ground on either of the pink wires...does result in a click... injector reaction. It appears that spark is present at all four plugs as well. Any other suggestions?
 

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Does it have a history of being parked for a long time??

It ran perfectly for five minutes..

Someone had an 1800, fine mesh screen
on injector had a blob of crap on it...

Something to think about...

Losing only one cylinder???

Another thing I mentioned earlier, where injector wires break out of the cable harness,
some shorts have occurred... Near a clip that holds the harness..
 

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Discussion Starter #16
Does it have a history of being parked for a long time??

It ran perfectly for five minutes..

Someone had an 1800, fine mesh screen
on injector had a blob of crap on it...

Something to think about...

Losing only one cylinder???

Another thing I mentioned earlier, where injector wires break out of the cable harness,
some shorts have occurred... Near a clip that holds the harness..

Bike has sat up for several months. As I said I picked this bike up about a year ago. It ran just fine on the test ride and sounded good. However the bike was run down and as I began to work on it.... I began to realize the previous owner wasn’t exactly a Rocket Scientist. I have found countless wire splices... for God knows what reason. Today checking the injector function.... I found both the injector signal wires that been cut and sliced...??

However...it is always the front cylinder and there is no question the additional engine noise accompanies the misfire.
 

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If the RPM drops than the de-compressor may come into play.
If you raise the idle above 1500 rpm do you still have it.

Some de-compressor issues were very loud...
 

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have you inspected the wire splices...... ?




may want to solder all splices... start with the injector wires.
 
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