Idle hunts when coasting

[SirGollum]

Hi Guys,

I'm still having a strange issue when I coast, or pull up at the lights...

So I drive down to the lights...and just before I get there I clutch in and coast up to the intersection....And the idle drops quite a lot....which seems to make the ecu over compensate, and then the idle will basically hunt for a little while until it gets things under control and stabilises.

Disconnecting the VSS from the ecu makes the problem go away. The VSS seems to be working fine though showing the correct speed etc.

This doesn't 'really' effect anything while driving on petrol other than being annoying, but if I try and use LPG, the motor will stall because the ECU cant seem to bring the rev's back up quick enough...

any ideas would be greatly appreciated!

Thank you

[antus]

Check the speed to use idle tables. It defaults to 5kph, but I find Im often coasting up to the lights with foot on the clutch at > 5 kph but < 20 kph and I expect it to idle and the revs used to hang a bit high. So I brought "Idle Fuel Param - Max road speed for idle A/F ratio" up to 20kph and now it does what I expect. Your problem sounds slightly different, but could be related.

[SirGollum]

Ok, thanks very much Antus,

Ill give that a shot.