02 GSXR 750 Falling on its face, STVA? or PC3 USB

I have a 02 GSXR 750 with 50k miles also. We overhauled the motor over christmas back to new. Went over everything and everything looks good. Broke it in on the street with no PC3 USB and it ran great, I raced at roebling with the PC3 on and it struggled out of 9 and onto the front straight as you can see in my video. It made it up to red line but it struggled after 11k. The STVA is cycling like it is supposed to on startup and not throwing a code. At Tally this weekend the bike would not go past 11k. I tried wiring the STVA open and it did not help. Vesrah told me to disconnect the PC3 USB and run the bike stock. I disconnected it for the rest of the weekend and it went up to redline no problem. ran mostly like stock. The only problem after that was it kind of broke up at some of the rpms when i gave it 100% throttle and fell on its face in some spots on the straight and did not produce the power. Any suggestions would be helpful.

I ALSO POSTED IN THE OTHER THREAD 03 GSXR 1k, I will check both threads.

 

can be a number of things check these
kickstand switch looped proper with a good connection?
battery cables have a good tight connection?
cam pick up sensor could be going bad
power commander could be going bad (yep they do go bad)
plugs fouled out or not in the best shape?
coils seated properly
check charging system and make sure it's charging properly, and then check batery and make sure it is a good battery
make sure all connections are tight, not corroded or burnt....



start there

 

ok,
the kickstand loop is good
the battery cables are good an tight
the cam pickup sensor i will check this weekend
the PC3 i will reset and check this weekend also
i put new plugs in it but will recheck this weekend same for the coils
the charging system is working good and the battery is new
when we put the motor back in we checked all the conections
(i think its going to come down to either the PC3, STVA, maybe the fuel filter or throttle bodys not being clean, or the cam sensor(wrenn with dalke said maybe the cam sensor, but vesrah said they have never had a cam sensor go bad without showing a code)
thanks for the tips

 

Make sure you check that the airbox is seated properly and tightly onto the throttle bodies. I had an issue with my 2002 750 that exhibited extremely similar behavior - bike ran well, until the upper rpm and until full throttle up there - it broke up. everything looked fine, and I fought this for a while. Finally one day when it was running well, I hit a bump in a corner and the behavior started up again - so I new something had to be loose somewhere. Turned out that the airbox wasn't exactly fit on and tight on all four throttle bodies.

Anyway - check it out.

 

As simple as this sounds check the fuel line and make sure it is not kinked. This happened to me on my 02 750 and it would run fine up until around 10k adn than do what you said yours is doing. It is worth a look before getting into all of the other things.

 

Could be an air problem. Check your exhaust and intake. I have had that problem before. I agree with the PC3 issue though. If you disconnected and it ran well, you may need a new one.

 

Thanks for the imput, I will be working on the bike tommorow. So i will respond soon

 

Ditch the PCIII and have the bike mapped with a teka tool from Factory.

 

Fuel pressure/volume tested?

 

why?

I can't wait to hear this one

 

Ok, heres what I found out. Absolutely nothing lol. I lubed up the moving outside parts on the throttle body, put the air box back on, everything was tight. reset the PC3 to zero map. ran it down the road 1-3rd gears to reline. it ran good. I loaded the custom map on it. and using just the send map button. took it out again. same 1-3 to redline. the bike ran good. soo,.... maybe just reseting the PC3, we will see at jennings i guess. thanks for all the tips.

 

If it revs properly in the lower gears but not in the top gears, it may have a fuel pressure/vol problem..i.e. fuel pump or filter issue.
Fuel demand/engine workload go up with overall speed.

 

if you still have issues disconect the PC completely

 

yeah i will give it a shot at jennings and will get to test out the higher gears. if the problem comes back i will unplug. thanks