OK, I'm still getting the old tacho dancing up to 8000rpm routine, which is supposedly dodgey fuel sender wiring. I've checked all wires associated with the circuit according the official Yamaha manual including the white to the ECU for continuity, all OK. I've tried a variable 10k resistor across the fuel sender connections so that I can vary it and hopefully find a resistance that stops it, still 8000rpm. I've shorted out the connections still 8000rpm. According to the Yamaha manual the only course of action left is a new ECU, but that's about 80 quid. Does anybody have any idea what this problem may be? As you can see I've tried all suggestions so far.

is it defintly 8k, are you running xup valve i know this can fire up a fault code.

are the clocks and ecu from the same bike / compatable ?

are you running the fuel pump relay via the bike ecu. rather than from the car loom ?

regards
agriv8

You sure you're using the right wire for the fuel sender - I only ask because its the mistake I made. . . . . It was the green wire with yellow stripe from the big connector on mine. For some reason the wiring diagram convinced me it was a grey wire....
cheers
Bob

It's definitely 8000rpm possibly 8500. I don't have a car loom, I've extended and added to the R1 loom, so the fuel pump is running from that. According to my wiring diagram, the fuel sender has a green and white wire, and a black earth wire running to it. The Yamaha manual also says there is a white from the clocks to the ECU, all are OK. The clocks and ECU are both 4XV. fault code for EXUP is 7000rpm, definitely not this. Only other one is 3000rpm for the throttle position sensor.

Might be silly questions here but there's only a few wires so I might as well ask.

I assume you are not using the fuel sender so have you tried a wire across the plug or taking the G/W directly to ground.

The wiring diagram does say G/W but a lot of previous posts say G/Y.

does the fuel light come on when you short the little green plug using NO resistors just a piece of wire

8k was the fuel sender on mine
only other thing would be exup

On my 5JJ I recall one wire being shown as the wrong colour and it may have been for the fuel sender. It's two years since I made my loom (extended R1 loom similar to yours) and it's now bound up so I can't go and check. I would trace the wiring back to the clocks to ensure that you're looking at the correct wires.

I don't think that the ECU has any control over the fuel fault code, though I could be wrong....

quote:

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Originally posted by Coose
I don't think that the ECU has any control over the fuel fault code, though I could be wrong....

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its a little green two pin plug

if you bridge a wire NO resistor your fuel light should come on

forget totally relying on any bike wiring looms most Ive looked at although helpful usually are about 30% wrong on wire colours

Shorting out the G/W to earth does put the fuel warning light on but only for a few seconds, so this tends to suggest I've definitely got the correct wire. I've checked for continuity on all wires back to both the clocks and the ECU, all are OK. G/Y according my Haynes wiring diagram and the official Yamaha Manual only runs from the clocks to the ECU. I do have an R1 fuel sender bur it's not in the tank, it's behind the scuttle. At worst this should register the tank as empty and turn on the fuel warning light, but even this connected does not cure the fault. By the way I appreciate the help so far, because this problem is doing my head in. What would happen if I cut the white wire from the Clocks to the ECU? Would the ECU simply not allow the engine to start because it has no self diagnostics?

the fuel sender has to be taken out.

the signal it gives could be monitored for correctness. (vibration?, no fuel in it bad connections?? oxidation??)

also if the fuel is digitally showed or measured you will get problems when your connections etc. arenīt soldered.

sow including your bridge could just spark a bit the dash will give then error because it says fuel sender is wrong.

solder a pot to the wires and play with the resistance. also look for bad connections basicly thats the problem you have.

anyway donīt ship your fuel sender with you its not nececairy and every weight saved is saved

Tks

I've tried a 10k variable resistor and adjusted to try and fix the problem but no luck.

the signal needs to go to?

Did you exclude as much as wire as you can?

you wouldnīt be the first wich has damega a wire while welding/cutting etc. etc.

Tks

p.d. just remerbering tha ti had on my bike loom a reset connector with that connector i could delete every thing from the bikes mcu regarding errors etc.

could be a solution for you to make sure history is removed. you do this while it is bridged...

then the light should get on..
iīm sure it also deletes the last measured fuel quantity...

problem is that if the last known value was lets say 3/4 full then you bridge it and its empty the mcu could be suspicous regarding accepting the signal.

the fact that the light lit is a good sign.



[Edited on 15/11/06 by tks]

have you done what I said mate??

1 piece of wire
disconnect the fuel sender
and bridge the green two pin plug on the loom with the wire just push the wire in side to side


no need to earth anything or finding specific coloured wires

its a little green plug from memory

this will make your fuel light come on PERMANENTLY

hope that helps chris

let us know when youve done exactly that

I've used the 5JJ clocks with a 4XV loom and motor but this is a quote from that thread I suggested earlier...

'98/99 ignitor (read ECU) plug has green/yellow wire which is the fuel level fault from the original meter this connection should be Earthed thro a 100 ohm (I've used a 0.25W 1kohm resistor) resistor to stop the fuel fault code to the meter '

Have you tried this?

You don't need to cut the wire. Just prise the top loom plug apart and pull the G/Y wire out and earth through a 1k resistor.

P.S. Make sure whatever you earth it to is actually 0V too! I had a couple of hiccups doing this. To be safe maybe take it to the negative terminal of the battery?

P.P.S. Have you printed out an A3 copy of page 413 of the R1 service manual? (http://www.bethman.net/r1forum/manuals.html)

Also page 403 has the fault codes... I'm sure you've seen this though from your comments.

Chris.

Just to clarify the Green and Yellow wire going TO the ECU is the one that needs grounding through a resistor as it uses this to tell whether or not there is a 'fuel level indicator' error as the Yamaha manual puts it...

Is the Green/Yellow the one running between the clocks and ECU, and has nothing to do with the Green/White from the fuel sender?

I've just tried grounding the G/Y to the ECU through a variable 10K resistor and adjusted it, still the error code. I've also tried the shorting out the connector on the loom and this puts the warning light on for a few seconds and then it goes out. I'm not convinced that the G/Y has anything to do with the error reading as this wire is now cut and still I get the error. The only thing that switches the LED on is shorting the connector, but then as I've said only for a few seconds. The G/Y has had no effect.

The only reason I've mentioned the G/Y wire is that when it is grounded through a 1k resistor on my install, the error code disappears and then if I remove the earth, it reappears...

With power to everything (i.e. ignition switched on) grounding this wire out and then leaving it floating (i.e. not connected, no potential) directly brings the fault code in and out again.

I would be very surprised if it was anything to do with the ECU to be perfectly honest. Although this does send the fault code via the Tacho connection to tell it to display the 8k error code for 2.5 seconds every 3 seconds.

Chris.

Sorry to be of no help...

Just to finish off this thread, I finally traced the problem to a dodgy ICU. I borrowed one from my local breakers, plugged it in, problem solved. I then had to fork out Ģ85 to pay for it, but at least the problem is solved. So much for bombproof Japanese electronics.

Cool

Does this mean you are going to actually use it?

Mike

Yeah Kurt!

Get it on the road! (I agree that practically its not the best plan - but you need to take us out in it!!)

Geoff

Sorry chaps, you'll have to wait until the Spring. I've spent all of my money for getting it on the road, on bits to fix it!