Fuelling trouble + more

Morning all. I already have this posted on TWF so im getting opinions from the left and right Ill try to keep this as short and to the point as I can.......

Removed the engine from my K4 SV650 (76bhp) and replaced it with a cam swapped,Hayabusa pistoned engine from a K3 with middle layer removed (built fresh myself) All wiring,ECU and PC3 remained from the K4 engine.

Dyno run 1 showed the injectors maxing out once the RPM went over 6k RPM. During this run the % throttle open value varied erratically between 80 and 100% while the throttle was pinned open. This problem was seen by the operator before and he traced it to a bad earth. The new earth was taken from the loom and problem is now sorted.

Dyno run 2 (today) showed the same problem with a twist. Bike running rich below 8k RPM and once over that the bike went super lean. Also the PC3 RPM readings are half that of the actual reading on the tacho and vary a lot sometimes even more than half. With PC3 disconnected the bike made almost 78bhp and had a good power curve

Tried the following:

Swapped injectors for another 650cc SV set
Tried a 1000cc SV set
Removed fuel pump,cleaned tank,refitted
Changed fuel tank to injector hose
Updated firmware
Unplugged emulator
Unplugged PC3

The Dyno guy is extremely knowledgable and races an SV himself. We are both at a loss as to what is wrong. Have I pinched a wire or something?? Are the K3 and K4 ECU`s sending different signals?? Is my PC3 sick?? This problem is starting to get annoying and expensive......

Well std methodology is to only change one thing at a time.

as it looks like it's PC3 that's the problem, run each trial again with and without PC3

also check RPM feed for PC3

If OK without PC3 for each trial, then PC3 would seem to be the problem.

or of course RPM signal to PC3

and I'd check every single connection and wire on the bike before doing the above trials (with a multi tester.

are there any FI faults showing?

C

Well std methodology is to only change one thing at a time.

We tried each thing I said individually

as it looks like it's PC3 that's the problem, run each trial again with and without PC3

No point in running the trials again with the PC3 plugged out as I wont get a duty cycle reading for the different injectors

also check RPM feed for PC3

As per electrical drawing??

are there any FI faults showing?

Nope

I have two spare looms here so i might change completely and see

Changed the loom and RPM problem gone.......

My dyno man has given me a quick check to do to verify if i still have the underfuelling problem so ill do that and fingers crossed everything will be ok...

Still a disaster...........Rang my Dyno guy and he said in order for me to test the injectors set the fuelling to 100@100% throttle for 6k RPM and the same up to 10k RPM. Tried this and the bike spluttered at 6k RPM (overfuelling,good sign) but when I put in the same values for 7k-10k RPM nothing happened and the bike pulled along fine

Anybody????? Am i looking at a new Power Commander?????

To be honest, with a problem as specific as this one and with the expertise you have going on at your end, I don't think there's a lot to be offered.

You haven't reached the max capacity of the injectors have you?

C

Originally Posted by Berlin

To be honest, with a problem as specific as this one and with the expertise you have going on at your end, I don't think there's a lot to be offered.

You haven't reached the max capacity of the injectors have you?

C

Dyno booked out this Saturday so cant get on to tell if they are maxing,someone suggested to me my timing could be out but i cant see how........Strange how the bike splutters at 6k rpm but not at 7k+ rpm with the 100 value for fuel