My hayabusa won't idle when it get hot
I still have to get it rolling roaded but is there anything I can do before then as I was planning on a track day this week

You could increase the idle speed a bit perhaps by adjusting the idle stop.

The idle is fine it idles when started but take it for a spin and it cuts out everytime you clutch and release the trottle

I have that Problem with my 08 R1 it gos on the rolling Road on thurs

Im Running a power Commander but i think it because of the pipercross Filter /no Airbox thats the problem so will be able to map it out

Kev............

It probably need the idle screw adjusting. Can't be 100% sure on BUSA, but it's probably got some form of cold start device that lifts the ilde when cold.

you either need more advance more fuel or more air by the sound of it. do you have a wideband sensor?

In other words it needs to be mapped properly

1. Have you got it connected to a Power Commander? If so disconnect it and see if it runs better at idle.

2. Have you got the MAP sensor connected to all 4 cylinders? if not it will run rich at idle when warm. When you first start the engine, it will be running on the fuel enrichment (choke) so it will appear OK but as it warms up the vacuum to the MAP sensor needs to read off all 4 cylinders to give a stable idle.

3. Have you got the cylinder temp and the airbox temp connectors back to front? I had this on my engine and is an easy mistake to make as the connectors are identical. My car ran rich when warm because the 2 temp sensors where connected to the wrong sensor, i.e. cylinder temp of 80 deg C but reading 20 deg C because it was connected to the airbox and visa versa.

Try this and come back with the results.

I don't have a power commander fitted as I am using an ecu flasher
The map sensor as far as I know is connected correctly
I will have to check the 2 temp sensors I don't think I have them wrong as the airbox sensor came attached to the wiring loom from memory
I plugged in the laptop last night and I had 2 f1 fault codes one for the O2 sensor
The other for the evap valve which I removed. The evap valve is just for returning vapour from the fuel tank back into the trottle bodies to be burnt .. So unless this has any adverse affect on the map or ecu it should cause a problem.
I'll have to check the O2 sensor .. I extended the wiring in the loom so I could fit the sensor
Would this have any affect on it reading???
Btw how would I know if I had the 2 temp sensor wire mixed up?? Probably have to check the wiring

[Edited on 12/6/11 by noc231073]

Or maybe there's a wire broken on the O2 sensor would that cause bad idle when hot

Engine Temp Sensor colour wires are Black/Blue and Black/Brown. Airbox Temp Sensor wires are Dark Green and Black/Brown.

Your engine must be an American import if it has the Evap Sensor on it and I don't know what the default would do if the FI light was on.

The o2 Sensor should not affect idle if the FI light is on.

ok been checking I dont have the 2 sensor mixed up...

the car idle fine when started up and if you just let it idle right up to temp its still fine but when you take it for a drive after ten minutes or so when your shifting down the gears or clutching to stop the engine just cuts out ...and its quite difficult to start with out your foot on the trottle keeping the revs up..

map sensor is ok also

So, does it idle when hot or does it just stall when decelerating only?

I have heard of the Throttle Position Sensors being slow to return so when you close the throttle quickly, the engine runs very rich.

If you open the throttle slowly and close it slowly does it still idle?

Opening the throttle to get it restarted would indicate that the engine is flooded with petrol and you need lots of air to get it running. Once it is started will it stay running or do you have to keep the throttle open to idle?

What is the idle speed when cold and what is it when hot? It should be 1150 RPM +/- 50 RPM

ive been at this all morning
check again with the laptop this morning my idle seems to bounce between 1050 and 1250 some times higher ...it quite rough..
the value for tps sensor at idle seems to vary from .6 and 1.2 thats without moving the trottle.
i did try and increase the idle up to 1600 and bring it for a spin. it was better but increasing the idle wouldnt be an answer to the problem.
when i got back from a run it did idle but when i blipped the trottle it died . i started it again and did the same and again it died. which brings me to thinking it might be the tps sensor... i did put it in the garage to put the laptop on it and it started ok and idled fine and i couldnt get it to die even when blipping the trottle ...
so as you can see it seems to be an intermitting fault ...sometimes ok and just wont idle other wise .....
I will try tomorrow (i had to go to work) to test the tps put the meter on it to see if its sending signals ...
would the flat shift affect it in any way???
thanks for your help btw.....

There are a couple of things to try.

One is to disconnect the TPS and see if the engine stabilises. It will run with the TPS disconnected but not necessarily very well.

Also try disconnecting the MAP sensor but not at the same time. Both items have a stand by and will run if disconnected.

If one or the other is dodgy, then it should run better disconnected.

Also, have you measured fuel pressure?

Sorted. It was old fuel in the tank that cause the problem it's been sitting there since I started the engine a few months back
New fuel and it was flying . In Mondello yesterday and it was flying never missed a beat simply stunning.
Thanks cosmic for all your help.
Learnt a lot with these problems . Every day is a learning curve

Good to hear it is now running well. Yes todays fuel has a shelf life of about 12 weeks before it will start to deteriorate (lose octane) so it will still burn but much slower. Glad to hear that it went well at Mondello Park.