c32 code on boosted busa

[dang3r]

Hello guys, greetings from Greece, this is my first post but I read almos all turbo section and .org helped me a lot with my project, so the time is came and I finally want to ask all you turbo gurus a question!

So, I got recently boosted 2007 busa, it is almost on its way for dyno mapping and the only thing Im waiting before do this is my water injection kit from US to finally arrive, but right now it has a pretty safe map in pc5 from another booster hayabusa with similar setup. The bike is internally stock with stock compression, s2000 injectors, vortech sfmu with 3.25:1 gain ration, walbro gsl392 pump, turbo is t04e and boost is limited by external gate at 6.5psi, my fuel pressure at idle is 30psi and on boost it is about 65psi. So my problem is that when I finally gave it a test ride, at hard acceleration after about 9000 rpm sometimes fi light comes on and bike starts to sputter and misfire, of course, as soon as I turn the ignition on and off problem disappears.

Dealer mode showed c32 code which as you probably know is malfunction of #1 injector and as many times as I tried it is always injector #1. After research I found that this problem occurs when injectors are working at very high duty cycle (locking) on boosted and big cc applications, but I don't know if this apply for stock injectors or any injectors. Although my wideband shows afr about 9.5 on boost just before this fi light pop up, also map i am using have +25s and +18s in cells from 8500rpm and the limiter , is it possible that I am overfueling and locking injectors and if yes why it is always the injector #1?

Sorry for the big post and my English, thank you for your time!!!

 

[Boosted Cycle Perf]

Your problem is your fuel pressure. It needs to be at 43psi. Make sure it's not connected to underneath the throttle bodies as it should only see boost. That's why it should be connected to the plenum.

Secondly, the ratio of the fmu is too low. Ideally you want a 6 to 1 ratio. You may be able to get away with what you have, but your going to be really working those injectors.

The sputtering is due to that overly rich afr. 9.0 is absolutly flooding the engine with fuel. I'd change your plugs with a new set of cr9e plus gapped at .018 just to make sure you don't have any problems on the dyno.

Lastly, you can run 8psi on a bone stock 2007 even with stock injectors. (Provided you have the right fmu)

 

[dadofthree]

Best of luck with it

 

[dang3r]

Your problem is your fuel pressure. It needs to be at 43psi. Make sure it's not connected to underneath the throttle bodies as it should only see boost. That's why it should be connected to the plenum.

Secondly, the ratio of the fmu is too low. Ideally you want a 6 to 1 ratio. You may be able to get away with what you have, but your going to be really working those injectors.

The sputtering is due to that overly rich afr. 9.0 is absolutly flooding the engine with fuel. I'd change your plugs with a new set of cr9e plus gapped at .018 just to make sure you don't have any problems on the dyno.

Lastly, you can run 8psi on a bone stock 2007 even with stock injectors. (Provided you have the right fmu)

hello and thank you for very fast replay!
My fmu is connected to plenum, I tried to raise the pressure at 40psi before but my idle rpm was too high, about 1400rpm and when I lower it to about 1000rpm bike dies and struggle to start again. But still I don't understand how static pressure at idle can affect fuel pressure at boost, mine is near 70psi at 6.5psi of boost, maybe you right about rate of gain being too low but since those injectors can flood the engine at 70psi maybe there is no reason to increase the fuel pressure. I also have 5:1 shim for my vortech, maybe I should try it

 

[Boosted Cycle Perf]

It probably dies because it's too rich. There's really no need for s2k injectors with a low boost fmu bike. It's just going to create more problems. Unless you go in to the ecu and change the injector calibration it's not going to run as good as it should just tuning the power commander.

 

[dang3r]

the only reason I went with s2k injectors is because i wanted to eliminate the need of 100psi fuel pressure on boost. I'm thinking of swapping injectors #1 with #4 for example to see maybe its injector malfunction, then ill try to pull some fuel in pc map cell's, if nothing works, maybe i should raise the rate of gain or swap with stock injectors, i dont know, to many things in my mind

 

[Kevin Jones]

I dont think you are going to fix your problem unless you start with the base things that Boosted told you about. Can you go into your ecu with ecueditor and change your injector compensation %? If that hasnt been done, I dont see how your ecu can possibly get the duty cycles right. I am by no means really good at this but I think you should either go back to stock injectors (which work fine on my bike up to 7-8lbs boost, stock motor just like yours) or change the compensation in ecueditor for the injector size that you have. Then you can start looking at your AFR at idle and smooth it out.

 

[Boosted Cycle Perf]

you've already got WAY too much fuel in it if your injectors are going static already. Adding even bigger values is just gonna make them go static sooner then they already are. If you keep dumping that much fuel in you're opening up the possibility for more problems like fowled plugs, cyclinder wash out, and worse broken rings, bent rods, or a blown head gasket. You can't compress liquids.

 

[Boosted Cycle Perf]

Almost forgot, even with bigger injectors, you'll still need the same 80-90psi fuel pressure. The only thing that will change is that you'll be running a smaller injector pulse width due to the injector flowing more.

 

[dang3r]

ill just swap them with stock injectors and raise the fuel pressure! Hope it will fix the issue. Thanks a lot for the info!!!