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Problem with bike (STVA - C28 Code)

55K views 21 replies 8 participants last post by  Deeznutz860  
#1 ·
2004 GSXR 600
13000 miles

OK, here's what happened.
Me and a few other bikes went riding this evening.
Pulled over and got something to eat.
went back out and started the bike as normal, however this time the red indicator light stayed on and FI starting flashing.
I shut the bike off and re started it and the same thing, but during idle the bike sounded fine
I tried to rev it and it wont rev past 8K RPM's
I removed the negative cable on the battery thinking that would reset the light, but it didnt.

So I decided to just go home. As I'm riding the bike runs fine as long as I'm below 8K rpms. If I ease the throttle open the rpms will gently raise up past 8k rpms. But if I open the throttle all the way, the bike hesitates as if I'm bouncing off the rev limiter but at 8K rpms

After some internet searching, it appears the code is C28...Secondary Throttle Valve Actuator which I understand is a common problem.

After pulling things apart, I saw that the butterflies was closed which explains why I couldnt rev past 8000 RPM's.

I've read somewhere that you can just remove the secondary butterflies, but this is what I have done.

Instead of remove the butterflies, they are now in the open position. However the C28 code is still there which is supposed to be since I never really solved teh problem.
I ran the bike through the gears and it now goes to the rev limit instead of just cutting off at 8Krpms. and it does this regardless of the throttle position (WOT, 3/4 throttle, whatever)
My question is: will riding the bike like this damage anything?
I do plan to get the problem properly resolved soon, but can I ride the bike like this without any worries?
 
#3 ·
You is fine riding with the C28 and actually I have yet to see a rememdy to fixing the error. You could remove the screws from Throttle blad and just carry on. If you want to fix it then you will need to get a STV or another working Throttle body.:thumbup:
 
#4 · (Edited)
It is NOT mandatory that I ride until I get it fixed, but I want to know if I do will I damage anything.
I'm searching for the actual part but I can't fine it anywhere (Ebay or craigslist)
I really dont want to purchase a new throttle body.

I would think this parts would be available whether its OEM or aftermarket
 
#5 ·
Its kinda hard to come buy as they usually sell the whole unit as one. YOU WILL HAVE NO PROBLEM riding with it on. unless you close it back again and if so you will have the no power until you slowly get on it again. Its hard to bypass the code as the computer reads thru resistance as to when to open and close the valve. I tried using resistors but it did not work.
 
#18 ·
#10 · (Edited)
bikebandit.com

if the part numbers match, then yes. If not, then no.


edit: doesn't look like it.

check gsxrdepot.com

or send an email to Marcel at http://gotmotoparts.com/MDG_RACING_INVENTORY.html he works closely with SRADIATOR on gixxer.com - you can send him a PM too if you want...but he's mostly SRAD (pre-y2k parts)
 
#11 ·
PROBLEM FIXED!!!

After speaking with a coworker, he is very familiar with sodering and has heard of this problem.
I took the STVA off and gave it to him. He brought it back the next day and said he really didnt see any breaks in the the connections, but he went ahead and soddered all of the points anyway.
Gave me the part and I reassembled it when I got home and no more code
Thanks guys for all your advice and help on where to look.
 
#16 ·
Now get this

Last night, I supported the tank up and looked at teh unit.
When I turned the fuel on, the FI light came on I started to wiggle the STVA and the light went off, then came back on
I was like WTF
So I turned the fuel off, and added a little pressure from the bottom of the unit to force it up (where the connector is), turned the full on and no code.
I removed my hand and the code came on
So I'm like W...T...F

I pulled the STVA off the bike and pulled the unit apart.
The part where the connector goes inside, I just gave it a bend so it's tilted now.
I reconnected the harness and turned the fuel on and it seems fine. It made the whine and the gear turned
So I reassembled the STVA and put it back on the bike, started the bike and no light.
I was like, it can't be that simple.
I rode the bike for about 3 miles, getting up to 15K rpms and no light.
Got back home and the bike is fine
I dont know what gives now
Eventually I know I will have to get another unit
But can anyone explain how or why this is happening?

Thanks