Author Topic: 99 Busa coil codes (Read 22060 times) Tweet

firemanjim · « **on:** February 03, 2016, 01:45:30 PM »

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.

speedduck · « **Reply #1 on:** February 04, 2016, 10:09:58 AM »

Could it be cam position sensor timing moved ?

firemanjim · « **Reply #2 on:** February 04, 2016, 01:14:45 PM »

Ran it with sensor unplugged with no change.

Ghost-Geezer · « **Reply #3 on:** February 05, 2016, 11:00:11 AM »

Bad ECU?

firemanjim · « **Reply #4 on:** February 05, 2016, 01:41:12 PM »

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.

Ghost-Geezer · « **Reply #5 on:** February 05, 2016, 01:50:07 PM »

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?

firemanjim · « **Reply #6 on:** February 05, 2016, 10:44:22 PM »

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.

RansomT · « **Reply #7 on:** February 06, 2016, 08:41:31 AM »

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.

firemanjim · « **Reply #8 on:** February 06, 2016, 02:48:20 PM »

Ransom, kickstand sensor bypassed, do you mean where the wires come out of the cover?

RansomT · « **Reply #9 on:** February 06, 2016, 05:54:29 PM »

Quote from: firemanjim on February 06, 2016, 02:48:20 PM

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.

Ghost-Geezer · « **Reply #10 on:** February 07, 2016, 02:12:47 PM »

Any luck with the wiring?

firemanjim · « **Reply #11 on:** February 07, 2016, 11:53:40 PM »

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.

Ghost-Geezer · « **Reply #12 on:** February 08, 2016, 06:25:01 AM »

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.

firemanjim · « **Reply #13 on:** February 17, 2016, 04:13:02 PM »

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.

RansomT · « **Reply #14 on:** February 17, 2016, 05:01:27 PM »

Next step would be to swap out the ECU, if you have one handy. Coil drivers bad in the ECU?

firemanjim · « **Reply #15 on:** February 17, 2016, 06:11:38 PM »

Ransom, did that. Going to swap the crank sensor.

Ghost-Geezer · « **Reply #16 on:** February 17, 2016, 07:34:52 PM »

I despise electrical issues.

Ghost-Geezer · « **Reply #17 on:** February 17, 2016, 09:11:19 PM »

Replace the R/R. Suzuki has the worst R/R's of the big 4 by a long shot.

firemanjim · « **Reply #18 on:** February 18, 2016, 12:54:06 PM »

What is the RR?

Ghost-Geezer · « **Reply #19 on:** February 18, 2016, 02:54:00 PM »

Quote from: firemanjim on February 18, 2016, 12:54:06 PM

What is the RR?

Rectifier/Regulator

busa2001 · « **Reply #20 on:** February 21, 2016, 03:35:27 PM »

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?

RansomT · « **Reply #21 on:** February 21, 2016, 05:30:04 PM »

I re-read this thread. Did you repin (twice) the '99 harness? Once for the '02 and then once for the '99 retro?

firemanjim · « **Reply #22 on:** February 21, 2016, 09:16:57 PM »

Yup. And rechecked everything.

busa2001 · « **Reply #23 on:** February 21, 2016, 09:31:27 PM »

Have you checked the timing to make sure it didn't jumped a tooth?

firemanjim · « **Reply #24 on:** February 22, 2016, 12:54:55 AM »

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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Author Topic: 99 Busa coil codes (Read 22060 times) Tweet