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Re: lean idle with closed loop fuelling
Posted: Fri Oct 07, 2016 6:07 am
by 9c1vs
Holden202T wrote:I would think either the idle afr tables has 14.7 values or its not going into idle afr table .....
personally i'd be making sure its not going into closed loop at idle and then using the wideband to dial in the idle fuel, then if you want to use closed loop idle after that you can, but I'm not sure why you'd want to as apposed to using the normal idle afr table ?
also keep in mind closed loop fuelling is different to closed loop idle.
Currently i have it using the main table. I wasn't bothering with the idle fuel table ad it is only a small cam. Having said that trying to get it to idle stable has been difficult. Is the idle table a prefered option? I had the target afr set to 14.7:1 as it seemed to make little difference to 14:1 and the change from 14.7 to 14:1 was causing the idle to become instable and not settle.
Re: lean idle with closed loop fuelling
Posted: Fri Oct 07, 2016 6:09 am
by 9c1vs
pman92 wrote:Is the wideband 0-5v offsets set?
Is the wideband measuring the opposite bank or somewhere different to the narrowband?
They sre set and the wideband is in a different location, but the readings were always the same with the other ecu and they match when cruising.
Re: lean idle with closed loop fuelling
Posted: Fri Oct 07, 2016 10:33 am
by Dylan
Is the NB heated? 2 wire sensors at idle can be unreliable especially with a decent camshaft. Low air flow and cooler gas too.
Re: lean idle with closed loop fuelling
Posted: Fri Oct 07, 2016 12:20 pm
by 9c1vs
Dylan wrote:Is the NB heated? 2 wire sensors at idle can be unreliable especially with a decent camshaft. Low air flow and cooler gas too.
Its just the stock 2 wire sensor.
Re: lean idle with closed loop fuelling
Posted: Fri Oct 07, 2016 12:54 pm
by Dylan
I'd be inclined to adjust off the wideband. If they match up during driving that's a good sign.
Post up a picture of a spark plug after a warm idle at 15.xxAFR on the wideband.
Re: lean idle with closed loop fuelling
Posted: Sat Oct 08, 2016 9:04 am
by Holden202T
yeah I agree, if the narrow band is not heated I wouldn't trust it at all at idle!
Re: lean idle with closed loop fuelling
Posted: Sun Oct 09, 2016 9:31 am
by 9c1vs
Excellent thanks for the help. I'll throw a pic up when i get a chance.