KrZy8 hard starting, intermittent missing

[rushes]

3 cylinder bikes are cool.

Ride the piss out of it.

 

[Niehart]

Rode with him a little bit coming home from Spearfish. Rush, he's already doing that.

 

[yamafitter]

3 cylinder bikes are cool.Ride the piss out of it.

Spoken like a true Turnip (Triumph) owner.

 

[dcarver]

Just curious, how'd you come to the conclusion that #2 cylinder is even the issue?
Another thread maybe?

Temp gun on the headers.. coolest temp on 2. Then dribbling a bit of fuel into vacuum test port she ran much better.

 

[TownsendsFJR1300]

Just curious, how'd you come to the conclusion that #2 cylinder is even the issue?
Another thread maybe?

Temp gun on the headers.. coolest temp on 2. Then dribbling a bit of fuel into vacuum test port she ran much better.

Thanks.

Since you already changed out the injector, and there's no vacuum leaks on the TB, (likely not as bad as it is) , I'd be checking to see if your actually getting an electrical signal to the #2 injector..

 

[RaYzerman19]

Just curious, how'd you come to the conclusion that #2 cylinder is even the issue?
Another thread maybe?

Temp gun on the headers.. coolest temp on 2. Then dribbling a bit of fuel into vacuum test port she ran much better.

Thanks.

Since you already changed out the injector, and there's no vacuum leaks on the TB, (likely not as bad as it is) , I'd be checking to see if your actually getting an electrical signal to the #2 injector..

Good idea too. Could be a bad ground in that circuit too.....

 

[audiowize]

If the aftermarket CC is taking vacuum off #2, and #2 isn't working properly, pull the CC off.

 

[TownsendsFJR1300]

Any updates?

 

[dcarver]

Any updates?

Yes.. just today. It's really frustrating not being able to wrench on KrZy8 myself, but right now it's time to make money while they hay is shining so to speak.

Spoke to Ivan at Hidden Power and he thinks it might be as simple as leaky plug cap shorting to the head. He replaced the stock OEM cap with a test cap (used to determine if coils are good) and it immediately smoothed out.

At first , we thought it was a bad injector in cyl #2, because when he dribbled gas down the intake vacuum port it ran better.

A new injector was purchased and installed but no happy ending.

Ivan has a test gas tank that can apply various inlet pressure to the fuel rail. When run > 47 psig, FJR nominal, KrZy8 ran better which led us down the injector trail.

At 47 psig fuel pressure, she was still hard starting and ran rough.

I have no clue why running a higher fuel rail pressure would cause KrZy8 to run better but now I think we're on the right track with the culprit being a leaky spark plug cap.

YamaMamma wants a pretty hefty price, about 80 USD. Found one on eBay, for 1/2 the price. It's worth the trouble to eBay it and see if it fixes the issue.

Funny thing is that this 08 motor runs really, really, really strong. Ask anyone who has heard it. It is one sweet engine - one where the tolerances just seem right and it came off the line as an over-acheiver.

I hope this is the fix.

If not I'll take an O'scope to Ivan's shop and we'll get freaking SERIOUS!

This bike HAS to get to 200K miles.. I'm freaking committed to make it happen.

 

[mcatrophy]

... he thinks it might be as simple as leaky plug cap shorting to the head....

Would be worse if running in damp conditions, although I suspect that might be masked by all the enclosures round the plug area. [Do you get damp conditions is California?]

Had this happen on my Trophy, which is why I suggested leads back in post #7. Curiously, the Trophy had a manual choke, using that reduced its misfiring, sort of consistent with your findings about increased fuel pressure or whatever.

Really hope this is the fix, the relief to have found a definite cause for such a problem is immeasurable.

 

[TownsendsFJR1300]

As a side note, its not un-common for the FZ6 engine ignition coil (2 coils) wire end to loosen up from the cap, show arcing inside at the end of the wire. (very bad connection)

The fix, 99% of the time, is simply cutting 1/4" off the wire, so the screw on end grabs some fresh wire...

 

[dcarver]

Still not fixed.

• New coils, wires and caps
• Suspect injector replaced
• Fresh plugs
• Hard starting, much better when warmed up
• When it's missing, missing on all 4
• Raising the fuel rail pressure from 47 to 60 smooths it out
• Plugs are indicating rich... black sooty, not wet, not oil
• No error codes
• All diagnostics work perfectly in DIAG mode
• For some reason, CO mode does not display.... not sure about that

Frankly, I think it has me and the tech stumped.

 

[Donal]

Still not fixed.

• New coils, wires and caps
• Suspect injector replaced
• Fresh plugs
• Hard starting, much better when warmed up
• When it's missing, missing on all 4
• Raising the fuel rail pressure from 47 to 60 smooths it out
• Plugs are indicating rich... black sooty, not wet, not oil
• No error codes
• All diagnostics work perfectly in DIAG mode
• For some reason, CO mode does not display.... not sure about that

Frankly, I think it has me and the tech stumped.

My understanding is that CO mode will not display on US models without the Barbarian mod................

 

[FJRay]

Is there any chance something has gone wrong in the air box causing a restriction??. There isn't much that will effect all four cyls.

 

[dcarver]

Ray, it gets weirder and weirder...

Today, nice and cold, she started up and ran freaking great. No missing, no hesitation, each muffler with equal and strong exhaust waves. Fast to throttle. Sounded perfectly happy.

I arrived at shop about 4 hours later...

Fired right up, sound GREAT.

..now what?

 

[FJRay]

Sounds like the same situation we had when we put that engine in. It sounded and ran like shit. We tied up a few loose ends and when it was started again all was fine. I'm would suspect something in the fuel delivery clearing itself. I don't like things that fix themselves

 

[Intech]

It was because I got the '07 running today. Your welcome.

 

[FJRay]

It was because I got the '07 running today. Your welcome.

The FJR planets are once again aligned.

 

[kaitsdad]

Check the pins in the ECM connector. I know the barbarian mod was done quite some time ago, but I suppose that the lock strip in the connector could possibly started to loosen with all the in/out, resulting in a marginal connection. And the fact that it's fixed itself and that the CO mode doesn't show - that points to something possibly loose in the connector?

 

[dcarver]

I have a used ECU purchased not yet received. I'm thinking a simple next step would be to dis-connect all sensor connections + ECU, inspect, then carefully reconnect and see what happens..Thanks Hal!