StromTrooper banner

1 - 9 of 9 Posts

·
Registered
Joined
·
4 Posts
Discussion Starter #1
Ok, here goes:

I have an 05 Vee with 50k miles of freeway commuting.
On a recent night ride home in heavy fog, I pulled in the clutch for a stop light about 10 mins into my ride and the bike died. I tried to refire it while coasting off the road, but no luck. My display was flashing FI and CHEC. I checked my engine stop switch on and kickstand up, all good. Next on to the fuse box - yep 10A Ignition fuse is toast. I put my spare in, thumbed the start button and smoked the replacement as well. Obviously there is a problem so bike is left overnight for future retrieval.

Thanks to this forum, I had some good starting points for diagnosis:

1. Removed all bodywork and carefully traced all the wiring harnesses, especially the know culprits. I pulled every connector along the way and cleaned / di-electric greased all contacts. No uglies found.
2.Sprayed the key Ignition with WD40 and compressed air.
3.Put in a new 10A Ignition fuse. Turn key on, fuse holds.
4.I operate headlight, taillight, turn signals, brake light, all good.
5.Time to Fire it up : fuel pump spins up, battery turns starter normally, bike coughs to life but running really rough and dies without throttle.
6.Check my homemade dealer code jumper -no codes. Hmmmmmmmm?

Next thoughts:
Fuel is good because I had burned the first half of that fuel tank just a few hours prior with no problem.
Removed Power Commander & all Farkles, same results.
Still no FI codes.

Electrical?
Battery checked for charging voltage, output & current leaks, all ok
Generator continuity & no-load volts test ok
Reg / Rectifier output volts good
Ignition coils peak volts & resistance test ok
CKP sensor peak volts & resistance test normal
Spark plugs indicate an overly rich condition

Fuel Injection?
Fuel pressure and volume pass test
TPS volts good and resistance good
STPS volts & resistance good
Injectors test ok
STVA- electrical tests ok BUT the STV operating order when the ignition is
turned on is way off: Should be - Half open, full close, Full open, 75% open,
Half open (20 seconds later)............ My secondaries just flutter rapidly back
and forth for about 30 seconds and then stop partially open.
So I unplugged the STPS and tried. No more flutter, bike starts, but still
running very rough (maybe just a marginal improvement)

My guesses are so far:
STPS or TPS or
Throttle body servo motor (STVA) or
ECM


Whaddya think? I am getting really tired of commuting by car in LA!
Any help appreciated, thanks
 

·
Registered
Joined
·
2,019 Posts
Well I think you have done such a good job on your write up that most can not even fathom a guess as to the problem. What interests me is the blown fuses, the fouled plugs and the STVA opperation. Seems too coiencidental to have several problems occure at once unless one has caused the other. (although the fouled plugs could be a symptom of the the STVA problem) However, since the root cause of the blown fuse was never determined I might suggest a wire trace for shorts concentrating on the ignition circuit, including opening of the loom as there have been reported problems within the loom itself. Hopefully someone with more accurate knowledge can guide you further.
 

·
Registered
Joined
·
6,689 Posts
Well your very thorough

I agree with above the blown fuses are indicative of a real problem or short. I burned some wires on my rear exhaust once so always check there

Any unusual conditions the day before ?

Will it run with 1 plug wire pulled ? / which one?

Injectors electrical?
 

·
Registered
Joined
·
2,361 Posts
"TPS volts good and resistance good"

When you had the bike in dealer mode looking for codes did you check the indicator reading when the TPS actuates?

You should see -COO at idle (1300 rpm or so idle rpm) on the clock in dealer mode. Then gradually roll throttle on in neutral and at about 1700 to 2000 rpm or so the -COO should show the - mark raise up. If so the TPS is in adjustment and functioning. If not you can readjust the TPS to signal the computer at the right time and it may fix it, or replace the TPS, which you will still need to adjust just like a used one.

I had to readjust my TPS at about the same miles. Mine has run fine since without replacing the TPS. I never checked the voltages on my TPS because I went straight to the dealer mode diagnosis. I think with time they get dead spot in the reostat.

I have no explanation for the fuse...but it may be fixed now. A badly adjusted TPS usually will not keep bike from running, they just die when the rpm falls below 2000 rpm. So you at least had two problems, the first of which took out the mainfuse.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #5
Thanks for the input gents. After running out of ideas I finally threw up my hands and ordered a used ECM ($200). Bingo! All good now and happy to be back on 2 wheels.
My best guess is that the ignition fault led to the ECM damage. I have now disected my wiring harness in search of the ignition fault and found no damaged wires. My guess here is that some moisture (bike was wet with coastal fog when I inserted key) entered my aging, marginal quality ignition and created a fault. Why the ignition fuse did not protect the ECM is still a question I cannot answer.
I plan to proactively replace the ignition and if time permits I will cut the old one open for a look inside and report back.
Thanks again for all the valuable info.
Final thought: i cannot even imagine what a dealer would have charged for this one!
 

·
Registered
Joined
·
2,019 Posts
Interesting. Since the gremlin that caused the fault was never found, I would worry about the new ECM though. Aso interesting is that the fuses stoped blowing after your first go through of the harness, ignition cwitch and connectors. It seems possible that your prodding temporally disrupted what ever was causing the fault. The reason I suggested opening the loom is that I recall others having internal splices that went aray.Let us know what you find out.
 

·
Registered
Joined
·
4 Posts
Discussion Starter #8
Update: I did replace the ignition, but the internals of the old one did not look to be in bad shape. I have put about 5K more miles on the bike since ECM replacement without a hickup. I have to conclude that I had a rare failure of the ECM. I also would not have guessed that this could open an ignition fuse.
Hope this might help someone in the future.
 
1 - 9 of 9 Posts
Top