Board logo

R1 Rev problem
gaz_gaz - 17/5/11 at 07:06 PM

basically the car has a 2000 Carbed R1 motor

it also uses the R1 clocks at present although i'll be fitting something else shortly.

the problem i have is this

the rev counter bounces around and appears to read half what the engines actually reving to, when the clocks read 5k rpm and the engines actually at 10k rpm the clocks start reading properly all the way to red line, although if you lift your foot off the throttle they drop back to half.

i've had a look and the yellow and black wire from the ecu isnt connected to anything and it appears the clocks are wired to a coil.

Now i've tried connecting the ecu wire back up and the clocks don't move at all, i'm thinking the ECU is at fault hence why its been wired up via a coil.

is there anyway to test the ECU to confirm before buying a replacement?

or does anyone else have any suggestions?


adithorp - 17/5/11 at 08:23 PM

Isn't that just the fault code?

Something along the lines of...
TPS = 3,000
EXUP = 7,000
Fuel level light = 8,000

Search "tacho tango" might throw something up. Not sure as the later ones give a code in the display.


gaz_gaz - 17/5/11 at 09:04 PM

thanks for the reply,

i'm not sure if its a fault code thing as it varies where it bounces to depending on engine revs,

and also the rev counter isnt wired via the ecu so shouldnt be displaying fault codes?

or am i missing something?


matt_gsxr - 17/5/11 at 09:14 PM

I am guessing, but it sounds like the tacho output on the ECU got blown at some point. Then to get things going they have used the low tension side of the coil output to drive the tacho.

This can work (actually it is what I have on mine, gsxr1100 driving an Aprilia R250 rev counter), but it all depends on what the clocks are expecting.

Maybe a circuit like this [see below, and what I used for my MS drive] (which doubles the number of pulses) is what you need. I don't think you necessarily need a new ECU as it could just be the tacho output from the ECU, which isn't essential.




Can't be confident of this, but it might fit the problem.

Matt


A1 - 17/5/11 at 09:49 PM

the rev needle does a dance if theres something wrong...is there any fault code on the digital display?
i should have the exact dances somewhere if you note the revs it pauses at


gaz_gaz - 18/5/11 at 06:50 PM

quote:
Originally posted by matt_gsxr
I am guessing, but it sounds like the tacho output on the ECU got blown at some point. Then to get things going they have used the low tension side of the coil output to drive the tacho.

This can work (actually it is what I have on mine, gsxr1100 driving an Aprilia R250 rev counter), but it all depends on what the clocks are expecting.

Maybe a circuit like this [see below, and what I used for my MS drive] (which doubles the number of pulses) is what you need. I don't think you necessarily need a new ECU as it could just be the tacho output from the ECU, which isn't essential.




Can't be confident of this, but it might fit the problem.

Matt



this is what i thought and have confirmed with the previous owner today.

the output from the ecu blew so he wired it to a coil but its now reading half