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Discussion Starter · #1 ·
Just picked up a 2006 r6 from a local person I know. He works on the road and the bike sat a lot while he owned it. When he returned from work, he wanted to take the bike out one weekend, but when he hopped on, it was spitting and sputtering. Long story short, I bought it for a deal.

Cylinder one is not firing. Pulled cyl 1 plug, checked compression, same as cylinder 2 (didn't check all 4, was feeling lazy. Matching cyl 2 was enough for me)

I did notice some slight rust, on the bottom of the coil by where the boot meets it. Coil and plug seem to be sparking fine, I also swapped cyl 1 plug and coil to cyl 2, misfire stayed on cyl 1.

I removed cyl1 fuel injector, actuated it by hand (hooked to power source) and it did spritz out whatever fuel was left in it.

The plug is not wet, which it presumably would be if the coil was arcing to the head and the injector was operating properly.

I did ohm out the ground circuit from the injector to the ecu- OK.

Do I just have a bad injector or am I overthinking something?

The bike does have a cat delete and flashed tune, not sure on the tune.

Would love some feedback/advice before I drop it off at the shop. I am an auto tech by trade, sad to say powersports are not my Forte.

Thank you,
Blake
 

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How did you determine that cylinder 1 was not firing?
Did you swap injectors to confirm that the issue stays with the injector?
 

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Discussion Starter · #3 ·
How did you determine that cylinder 1 was not firing?
Did you swap injectors to confirm that the issue stays with the injector?
Bike runs like garbage, and I can hold my hand on the cylinder 1 head pipe while it's running.

Is there a specific method for checking voltage to injectors? I tried key on engine off, but didn't see any voltage on cyl 2 injector either, which makes me think there is some other way to check.
 

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Discussion Starter · #4 ·
Swapped coil AND plug from cylinder 1 to cylinder 2, no change. Stays on 1.

Swapped cylinder 1 and 2 fuel injector, no change, stays on 1.

Swapped ecu from my other 2006 r6, no change, stays on 1.

All of these problems really seem to lead to a base engine problem, but the compression is good? I don't understand.
 

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Can you hold your hand on cylinder four?
Do you have enough length in the wire harness to the coils to swap cylinders one and two?
 

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Can you hold your hand on cylinder four?
Do you have enough length in the wire harness to the coils to swap cylinders one and two?
When you swap coils, you unplug them and swap them. You don’t leave them plugged into the wiring. That wouldn’t isolate the coil. You’d still have the wiring in the mix.
 

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UR B-hind Da 8 Ball
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You say you have good compression. What is the actual reading?

You probably should ring out the wiring from the coil to the ECU.
 

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Discussion Starter · #9 ·
You say you have good compression. What is the actual reading?

You probably should ring out the wiring from the coil to the ECU.
I believe it was around 145 or so, but engine was cold.

It was the same compression on cylinder 1 and 2, so if 2 fires, it shouldn't be a problem on cylinder 1.

(I know numbers sound a little low, but I'm sure the valves haven't been touched in 19k miles)

The bike has spark from that cylinder
 

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UR B-hind Da 8 Ball
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I believe it was around 145 or so, but engine was cold.

It was the same compression on cylinder 1 and 2, so if 2 fires, it shouldn't be a problem on cylinder 1.

(I know numbers sound a little low, but I'm sure the valves haven't been touched in 19k miles)

The bike has spark from that cylinder
You need compression, spark (at the right time) and fuel. You claim to have all three. Well, something isn’t correct. You are missing one of them on that cylinder. I know it’s tough, but you need to check compression when it’s hot. I have a feeling you may be losing compression as it heats up (for instance as the valves heat and expand they start to hold the valve open slightly because the clearance is too small) or spark as resistance builds due to heat in a corroded connection.
 

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When you swap coils, you unplug them and swap them. You don’t leave them plugged into the wiring. That wouldn’t isolate the coil. You’d still have the wiring in the mix.
I'm aware. It was a fleeting thought on isolating the wiring but as he points out, 1-2-4-3 would become 2-1-4-3.

.... Cyl 4 runs fine
Only reason I mention is inner vs outer cylinders pipes are known to be different temps and I have no idea how long you're running the engine.
 

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Discussion Starter · #12 ·
You need compression, spark (at the right time) and fuel. You claim to have all three. Well, something isn’t correct. You are missing one of them on that cylinder. I know it’s tough, but you need to check compression when it’s hot. I have a feeling you may be losing compression as it heats up (for instance as the valves heat and expand they start to hold the valve open slightly because the clearance is too small) or spark as resistance builds due to heat in a corroded connection.
Cold start, cylinder 1 does not run. Can't heat up the cylinder if it won't run
 

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Discussion Starter · #13 ·
I'm aware. It was a fleeting thought on isolating the wiring but as he points out, 1-2-4-3 would become 2-1-4-3.


Only reason I mention is inner vs outer cylinders pipes are known to be different temps and I have no idea how long you're running the engine.
Not long to avoid damaging it
 

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I'll say it. Leakdown test the motor.

Have you recently installed a cam chain tensioner or heard any racket from the top end? Just spitballing, but you may want to verify timing if you have fuel air and fire.
 

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Discussion Starter · #15 ·
I'll say it. Leakdown test the motor.

Have you recently installed a cam chain tensioner or heard any racket from the top end? Just spitballing, but you may want to verify timing if you have fuel air and fire.
I would be more keen to agree if if wasn't just cylinder one, but I'm not sure.
 

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Long shot since there shouldn't be much if any difference between left/right side of the rail but, how's the fuel pressure look'n? We've also read about some kinked hoses. (inadvertently flipping them during reassembly could be a contributor to that issue)

I'd look for a way to absolutely verify whether fuel and spark are occurring during engine run.
 

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It's rare, but check the cdi. It may be bad. Also, check your ground connections again. Also ohm your conductors.
 

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Discussion Starter · #19 ·
It's rare, but check the cdi. It may be bad. Also, check your ground connections again. Also ohm your conductors.
Checked ground and it is good. I haven't messed with the machine in a while now. Where is the cdi located on these?
 

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Discussion Starter · #20 ·
Long shot since there shouldn't be much if any difference between left/right side of the rail but, how's the fuel pressure look'n? We've also read about some kinked hoses. (inadvertently flipping them during reassembly could be a contributor to that issue)

I'd look for a way to absolutely verify whether fuel and spark are occurring during engine run.
I haven't had a fuel pressure tester on it, I thought about it. I almost pinched the fuel line myself, but I'd say highly unlikely as to my knowledge I was the first to remove the tank (previous owner definitely didn't)
 
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