Ecu problem, I think.

Just recently got bike back together, Robinson trans. upgrade, and cam degreeing. Put about 125 miles on her, stopped and got gas and wouldn't restart. Let sit about 15 min. and started. Shut off to put helmet on , wouldn't restart. Went home, got trailer, still wouldn't start, took her home and rolled into garage, still wouldn't start. Started testing this morning, fuses and relays all good, hooked up Tune ecu and had no codes. Tried to start and fired right up, shut off and started several more times, sounds great. I think inside ecu is getting hot, something is going open and then cooling off and like resetting. If ecu is at fault, how is best way to proceed, Neville sent me a tune to get bike to tuner, and then had dyno'ed, this was a couple yrs. ago. Does bike have to be running to get tune out of ecu. and store in tablet? What is the criteria for getting a used ecu? Bike is an 05 rocket III, with up dates and warmed up engine. Thanks for any help or thoughts. Gerald

Hmm could it be a dodgy switch like clutch or sidestand for example?

If you wish to download the map out of the ECU, you just need ignition on (and on a battery charger because it takes several minutes to download)

R-III-R Turbo said:

Hmm could it be a dodgy switch like clutch or sidestand for example?

If you wish to download the map out of the ECU, you just need ignition on (and on a battery charger because it takes several minutes to download)

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Thanks for the response, that's good news. I'm still checking, but I'm pretty certain the ecu is the problem. Never fails to crank and doesn't drag down. Volts stay up.

Would be probably the first failed ECU I've heard of in Rockets. Though I had one brick one time when the map file was corrupt.

Presume you have done a spark test?

R-III-R Turbo said:

Would be probably the first failed ECU I've heard of in Rockets. Though I had one brick one time when the map file was corrupt.

Presume you have done a spark test?

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Yes, if plugs fire, she starts immediately, and if it doesn't fire, it won't. I converted to coil over plugs about two years ago, and never had an issue.

like R-III-R Turbo said i have never seen a bad ecu. even dealt with shorts on two 2005's that just blowed fuses and never hurt the ecu.
does it always turn over good?
does it run good when it does start?
have you checked the 12 volts on the coils?
have you checked if the ecu is grounding the coils when it fires and when it doesn't?

TURBO200R4 said:

like R-III-R Turbo said i have never seen a bad ecu. even dealt with shorts on two 2005's that just blowed fuses and never hurt the ecu.
does it always turn over good?
does it run good when it does start?
have you checked the 12 volts on the coils?
have you checked if the ecu is grounding the coils when it fires and when it doesn't?

Click to expand...

Just got her back together a couple weeks ago, installed new battery with 325 cca, spins engine over fast. I converted to coil over plug a couple yrs. ago and never experienced a problem. Checked volts at coils, when it on, 12 volts, when breaks down 0 volts. Put an spare plug in coil, cranked over, intermittent to no fire. I've seen ecm's go bad on cars and trucks but very seldom. This started last Friday, went to the cemetery to visit my brother, left there and went to courthouse to pay taxes, left there and stopped to get gas. Wouldn't start back, cranked fine just no firing. Tried about ten min. later, started right up, shut off to put helmet back on, wouldn't restart. Went home, got trailer, tried again, still no go. Got home, pushed in front garage, and quit for the day. Next morning started right up, went to take her to back garage, and she shut off. So I've tested and tried for a day and a half, keep coming back to ecu, so I'll buy a used one, load my tune and see what happens. Thanks for your response, will let you and R-III-R know as I go along.

once and a while guys have trouble with the purple wire being corroded and i suspect that may be your problem so what i would do is jumper the coils with a 12 volt supply and see if it stays running. now i think that that power comes ignition? any way it is simple enough to do.

TURBO200R4 said:

once and a while guys have trouble with the purple wire being corroded and i suspect that may be your problem so what i would do is jumper the coils with a 12 volt supply and see if it stays running. now i think that that power comes ignition? any way it is simple enough to do.

Click to expand...

Thanks for the reply, I bought a used one off e-bay, be here end of the week or beginning of next. I'll check wires out, didn't see any problems earlier, and shook everything I could. Bike's been down all year, just got her back together about two weeks ago, so anxious not to miss anymore riding. If ecu is not the problem, I'll just have a spare.

@Rocket Scientist needed one an ecu awhile back, i forgot problem. I have several theyre just 1700 miles away in storage.