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Discussion Starter · #1 ·
I've read every related thread (and unrelated too), but can find but nothing quite like this... My '05 bird now has 40,000km and has been developing a misfire problem for about the last 10,000km. It always starts easily (cold or hot), and idles relatively smoothly until warmed up - and then it idles like a Harley (thanx to the Yoshi pipes everyone can now hear it :crap: ) There is no particular rhythm to the miss. Also surges at part throttle, but still feels smooth/strong under acceleration.

I've changed the spark plugs, fuel filter, fuel pressure regulator, and gapped the valves all to no avail. Even fitted a K&N air filter and new brake pads for good luck.

Finally realised it was time to try finding this white diagnostic connector again. Turns out it was buried under the ECU, and is black. No matter, it revealed codes: 7, 8, 9, pause, 1, pause, [start over again]. I thought they were meant to be in ascending order?!? :huh: Anyway, performed a reset and will check again tomorrow.

With so many codes listed (coolant temp, TPS, IAT, MAP) I'm thinking a harness connector, or some other earthing problem... Can anyone suggest where to start looking for this fault?
 

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I know nothing of the FI machines, but.... Shot in the dark here...could it be a failed wax unit (FI engine warm up gizzmo) that is not turning off after engine warm up. I believe this might produce a rich mixture condition. Hows the gas mileage been over the last 10K kilometers? I believe poor mileage is also a symptom. This somewhat plays into the"coolant temp" code and such.

Tony
 

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Discussion Starter · #3 ·
Nah I doubt it's the wax unit because when warming up the fast idle begins to drop at 45 degrees like it always has. Interestingly the kilometreage (aka mileage) seems to have improved, suggesting leaning out. There's only 1 coolant temp sensor, so any anomaly should be visible via the gauge - but isn't. I'm tempted to see if the 330 ohm resistor in place of the EGO sensor does anything. There are several threads on this claiming to be a fix, but isn't this just a work around for bad tuning? Why would an ECM lean a mixture to the point of misfire, when misfiring causes some pollutants they are trying to avoid?I still don't get why there are so many fault codes logged. The only thing they have in common is they are in close proximity to each other...
 

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Is the ECU correctly strapped down.. The XX doesnt like a free floating computer...
 

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Discussion Starter · #5 ·
Yeah the the ECM is strapped down with the factory rubber band, which doesn't look very secure to me. I'd bet those tiny harness wires would develop an intermittent break if it were left to bounce around...
 

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Hi Wiggly
Replied earlier but seems not to have worked!
Misfiring on operating temp has hallmarks of ignition coil!
Could you borrow a known good one?
If you let it idle for a while will some of the headers start to cool off? (careful here!)
Not sure about the bird but some "ordinary brand" bikes use left coil for pot 1 & 4 and right one for 2 & 3 sure bird is same!
Smooth acceleration seems at odds with this theory but it still might not be up to spec?
Cheers and good luck.
 

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Discussion Starter · #7 ·
Well b#gger the bird black! 40km round trip to work and it's still bucking like a bronco, yet there are no fault codes. Perhaps it's upset at the bald front tyre?!?
 

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Wiggly I just came across this thread, I also had the same problem and come to find out it was a weak battery. How I found out was when I ran the battery down I jumped it off with the truck and kept the jumper cables connected and it ran smooth. So I swap batteries with my 636 and same results. I ordered a new battery and now she's good to go. I hope this hepls you.
 
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