Help. High tickover.

[blacktiger]

I need help. Yeah I know.....
When fully warmed up, my 955i has a high tickover which will drop back to 1100 after a while (several minutes) but when riding it stays at around 1500rpm. I've replaced the crank speed sensor and the rubber gasket around the IACV but it's still doing it.
Anyone had similar?

[Bixxer Bob]

Did it do it after being stood a while? Was battery ok when you started it? Or did it slowly develop?  Need a few clues.....

[blacktiger]

It's been doing for quite a while now. Yes the bike has been standing lately but it gets put on the Optimate regularly and was doing the high tickover bit all last year. It's not the battery.
Other symptoms are it stalls immediately after getting fuel which is why I thought it might be the crank speed sensor. Been doing that for years.
The IACV gasket got replaced because the original was looking sad last time I had the tank off and I thought it might have developed an air leak in there.

[Bixxer Bob]

Reason I asked about battery is if you start it with a weak battery it can lead to corrupt trims (voltage not high enough to save when turned off).

The only time I've had a similar problem was either when I'd put too much fuel in the bottom of the map while trying to stop popping and also when I'd raised one of the trims too high.  I'd reset the trims and reload the map before I did anything else. 

If you have TuneECU I'd check the voltage on the O2 sensor too.  If it's U/S and constantly richening the trim that would do it.  Does it smell rich?

[blacktiger]

No doesn't smell rich. Any idea what the O2 sensors should read. I do have Tuneecu and did plug it in but on these with the SAGEM injection it's limited what you can do. I was looking for fault codes but there wasn't any.

[Bixxer Bob]

O2 should read 0.46v

If you can post up a pic of your readings it'll help spot anything untoward.  Which tune are you running?

Like most fuelling probs this sounds like an air leak.  The ECU will sense throttle posn (closed) and the engine rpm and if too high, will close the IACV until the revs drop to the programmed level.  If, however, you have an air leak, even completely closing the IACV won't drop the revs enough so it'll sit at whatever it can achieve.  You need to look in all the usual places.  If it's not running rough but is only a tickover prob, that suggests all three pots are getting a share of the leak so that might help find it.  It's quite likely that over time , the ECU will have trimmed in extra fuel too so the screen shot will show this although I see it's not smelling rich.

My tired brain can't think of anything else tonight.

[blacktiger]

O2 should read 0.46v

If you can post up a pic of your readings it'll help spot anything untoward.  Which tune are you running?

Like most fuelling probs this sounds like an air leak.  The ECU will sense throttle posn (closed) and the engine rpm and if too high, will close the IACV until the revs drop to the programmed level.  If, however, you have an air leak, even completely closing the IACV won't drop the revs enough so it'll sit at whatever it can achieve.  You need to look in all the usual places.  If it's not running rough but is only a tickover prob, that suggests all three pots are getting a share of the leak so that might help find it.  It's quite likely that over time , the ECU will have trimmed in extra fuel too so the screen shot will show this although I see it's not smelling rich.

My tired brain can't think of anything else tonight.

When riding it it actually goes good. You wouldn't think there's anything wrong. It's purely at tickover. Yes I thought air leak which is why I replaced the IACV gasket. But as I said originally, it will drop down to 1100rpm after a few minutes at tickover.
Thanks for your efforts tonight John.

[NKL]

Not anything as simple as a sticking throttle cable?

[Timbox2]

When I had similar symptoms to this, it turned out to be the IACV stepper motor/valve itself.

[blacktiger]

Not anything as simple as a sticking throttle cable?

I will be lubricating that....................when the weather warms up a bit. One of the things I have to try.

[blacktiger]

When I had similar symptoms to this, it turned out to be the IACV stepper motor/valve itself.

And the cure was to get a new one????? Unfortunately the test on Tuneecu doesn't work on these SAGEM bikes. Or rather, doesn't SEEM to work.

[Timbox2]

When I had similar symptoms to this, it turned out to be the IACV stepper motor/valve itself.

And the cure was to get a new one????? Unfortunately the test on Tuneecu doesn't work on these SAGEM bikes. Or rather, doesn't SEEM to work.

yep, new one, you can sort of test em by taking tank etc off, reconnecting battery and power cycling the igniton as you watch the little white valve, I could tell mine was sticking /not returning properly, be aware you will get a MIL light if you do this as certain things arent connected up, but you can clear the faults with Tune ECU after.

[Bixxer Bob]

You could always take it apart and clean it eh Tim? 

[blacktiger]

When I had similar symptoms to this, it turned out to be the IACV stepper motor/valve itself.

And the cure was to get a new one????? Unfortunately the test on Tuneecu doesn't work on these SAGEM bikes. Or rather, doesn't SEEM to work.

yep, new one, you can sort of test em by taking tank etc off, reconnecting battery and power cycling the igniton as you watch the little white valve, I could tell mine was sticking /not returning properly, be aware you will get a MIL light if you do this as certain things arent connected up, but you can clear the faults with Tune ECU after.

Thanks. Something else to try.

[Timbox2]

You could always take it apart and clean it eh Tim? 

yeah, get back to yer Guzzi you