SuzukiHayabusa.org
TECHNICAL => HELP! => Topic started by: firemanjim on February 03, 2016, 01:45:30 PM
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So, have a 99 Busa that is breaking up at high rpm--Above 8000 and high load on dyno, doing 100% runs right now. Getting misfires and all 4 coil codes show up. Changed plugs and checked charging-- it is charging well, still does it, going to change to another set of coils and check crank sensor wiring but anything else you all can think of?? AFR good all along.
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Could it be cam position sensor timing moved ?
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Ran it with sensor unplugged with no change.
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Bad ECU?
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Tested all coils and they are ok, then stole 2 good ones off of the turbo bike and still the same, swapped out injectors and checked fuel pressure-- still the same-- swapped back to 99 rotor and ecu from the 02 I had installed, still the same.
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That symptom, if it were a car with spark plug wires, would be a classic sign of bad wires breaking down under load. Is all the ignition wiring original?
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I agree-- it looks original, next I will try bypassing the hot wire to coils with 12 volts from the battery and see what happens.
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Isolate the crank position wires from the stator wires. The wiring gets old and cracks there due to heat and the change from the stator does havoc to the crank sensor signal.
Let us know what you find. I still have one in the shop doing something similar and figure out why.
Oh, make sure the kick stand sensor is o.k. , they have been known to vibrate at higher RPM when loose.
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Ransom, kickstand sensor bypassed, do you mean where the wires come out of the cover?
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Ransom, kickstand sensor bypassed, do you mean where the wires come out of the cover?
Yes, cut the harness open and rewrap from the cover to the plugs. Separate the yellow stator wires from the 2 CPS wires and retape them.
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Any luck with the wiring?
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Won't be able to get to it until next week, was at brothers for the weekend superbowl party then headed to DC tomorrow til friday.
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I drove across the 14th St Bridge for 20 years working at Union Station over by the Capitol Building and the Senate Office Buildings. Traffic was, and still is, a bitch. 20 mile commute took 1 hour each way every day.
I'll bet when you get back home, that wiring will fix the bike. Ransom-T has hit/zeroed in on the potential cause. Seen it a dozen times on the old and new Harley's.......most times it was either the plug from the stator to the rectifier got hot/shorted to the cases or the stator itself just took a dump. Wire insulation had gone thru so many years and heat cycles, it actually became brittle and the insulation would crack and short out either intermittently to the cases/ground or eventually full time. Sometimes the plug would get hot enuf to melt to the cases. Battery would lose amps and bikes would begin to "break down" under load at higher RPMs.
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OK guys, back at it-- separated wires from stator cover up and ran crank sensor wires away from stator wires. Ran 12 volts to coils from battery through a relay and it still misses and gives all 4 coil codes.
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Next step would be to swap out the ECU, if you have one handy. Coil drivers bad in the ECU?
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Ransom, did that. Going to swap the crank sensor.
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I despise electrical issues. :td:
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Replace the R/R. Suzuki has the worst R/R's of the big 4 by a long shot.
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What is the RR?
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What is the RR?
Rectifier/Regulator
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Sounds like a timing issue, did you swap the Crank Position Sensor wires around when you upgrade to 32 Bit ECU? and back when you went back to 16 Bit?
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I re-read this thread. Did you repin (twice) the '99 harness? Once for the '02 and then once for the '99 retro?
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Yup. And rechecked everything.
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Have you checked the timing to make sure it didn't jumped a tooth?
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It runs great til about 7500-8000 then starts to miss and the 4 coil codes come up, makes great power til then.
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Jim have you looked at the starter clutch crank index to be sure your timing mark is correct
anything thats timing related is sort of covered when you pull the cam sensor plug , but grasping at straws now
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I'm real interested in fix for this. It's a head scratcher for sure!
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Pulled cover and crank gear is indexed correctly, unplugged cam sensor and no change as well. I am running a Gen 2 intake with stock cam timing, and have heard it is necessary to run offset cam pin--- and have heard you do not need to. How can I check this? Bike makes really good power to just about 8000 then starts to miss and coil codes come up.
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Pulled cover and crank gear is indexed correctly, unplugged cam sensor and no change as well. I am running a Gen 2 intake with stock cam timing, and have heard it is necessary to run offset cam pin--- and have heard you do not need to. How can I check this? Bike makes really good power to just about 8000 then starts to miss and coil codes come up.
Yes, you need an offset cam pin to run a Gen 2 cam in a Gen 1 (same offset cam pin that a Gen 2 uses just put in backward). However, it should have run until redline if you disconnected the cam sensor.
I just had an issue with a 99 that had a repinned 02 harness, it was the crank sensor wiring...they are backwards for 99-00 only.
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That was next on checklist-----
Edit that-- just tried it an NOPE!
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You need the offset pin to run gen2 cam in gen1...
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But by disconnecting the cam sensor I should be bypassing all that----
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Wonder if the ECU determines timing by the differences between the pulses of the cam and crank sensor? If it does, then upon startup with the intake cam pin in the wrong position, the ECU will set the timing wrong even if you unplug the crank sensor after it starts.
Question: does this bike have an airshifter?
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No airshifter. And good question. If all else fails I will pull cam and swap stocker back in. Have Dyna Arc 2 I am going to toss on and see if improved spark helps before that.
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Stator issues at high RPMs causing a shortage of volts/amps to the ignition under load? And/or bad rectifier/regulator as I mentioned earlier. Tough nut to crack.
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Greg is sending me a wiring harness for the ARC 2 and I ordered the offset cam pin, pulled cam covcer and yanked the stock pin.
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Just installed the offset cam pin and no difference whatsoever, put a volt meter and a battery charger on it and ran again, with no appreciable voltage drop and same.
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I'm out of suggestions :mrgreen:
All I know, if I roll a sportbike on the dyno and it breaks up at high RPM, I automatically check fuel pressure first. Seen lots and lots of bikes have bad fuel pumps. Folks seem to think you can leave MR12 or Q16 or MRX01 in the tank for weeks after a race.
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Already did that,it is all good.AFR is good as well.
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Change over the battery to a WPS Lithium Ion and replace the rectifier/regulator next. After that, I am out of ideas as well.
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Harness issues?
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Maybe, but have bypassed coil feed from ecu , going to try putting entire stator,crank sensor from racebike on.
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Stator sounds like a potential source of the issue. Good idea.
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So here is the latest, replaced stator/crank sensor package and regulator, stator was a bit corroded, not a bit of difference!!! Even tossed a Power Commander on it and added some fuel up top, not a bit of difference, kinda out of ideas--- anyone got a spare wiring harness for a 99-00 Busa??Or what years will fit?
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All symptoms point towards a problem with the electrical system but I have to ask; have you done a leak down and compression check to verify the engine is mechanically sound? Some problems can manifest them self in a strange and not logical way.
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So here is the latest, replaced stator/crank sensor package and regulator, stator was a bit corroded, not a bit of difference!!! Even tossed a Power Commander on it and added some fuel up top, not a bit of difference, kinda out of ideas--- anyone got a spare wiring harness for a 99-00 Busa??Or what years will fit?
Here are differences. 99-00 same. 01-07 same. Difference between the 2: Throttle bodies connector. Fuel Pump connector. The rest of the differences are a matter of re-pinning the harness.
I "think" I have a 99-00 harness somewhere ... would have to look for it.
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Just had this same problem with customers bike (Busa) ,Went nuts trying to figure it out. Last thing done was to check cam timing and sure enough the intake jumped 1 tooth. Hope you fix the problem - feeling your pain !!
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Engine is out as it had a noise, so will be checking all of that. Compression was great, had a couple ex valves a bit tight. Installed a nice clean 06 harness, so fingers crossed.
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sounds good keep us posted
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Back together, cam timing was correct but checked and intake lobe center was way off at 98( Has Gen 2 cams and gears.Tossed an APE gear on intake and set at 108, now with 2006 Harness it screams to redline with no misses or codes.
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Hope that takes care of it...I just got done degreeing my cam set them at 105I 106E....