Ign Advance Idle - Help

Give input on tuning as well as any tips and tricks you may have. Also feel free to share base mapping files for various engine types.
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Chappb
Posts: 6
Joined: Thu Sep 24, 2020 5:16 am
ECU Model: S40 Pro
Distributor: Watsons Wakefield

Ign Advance Idle - Help

Post by Chappb »

I can appreciate there are already a few topics with info on this already on the forum, but i've reread those multiple times and i'm still struggling!

Honda B16a, no idle valve, using ign advance to try and control idle. Played about using open and closed loop with different upper and lower limits. Finally settled on just putting in 16 degrees across the board and turning the PID off, as reading up on the engine i've found that the OEM setting is 16 degrees at idle for this engine.
Now it will warm idle at this setting having adjusted the butterly to suit the idle speed i want.
But for some reason, even when idling warm, i'm seeing around 14.7 afr but all of a sudden it will drop to around 10.5 afr.... without any change in idle speed....eh?? And that's also when the figures in the starting fuel map are at 0 having done at least a minute idling.

I'm hoping someone can give me an idiots guide here if i've been overthinking things! Feel free to correct me on anything at all that might point me in some successful direction!
Cheers
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Ign Advance Idle - Help

Post by Rob Stevens »

Turn all lambda and idle control off.
Set throttle stop so to require around 4-5 degrees of ignition at your target idle speed when hot.
Then turn closed loop on, I'll post you some setting from my engine that work well later.
I'd be very surprised if Honda used 16deg of ignition !!! at idle.
Chappb
Posts: 6
Joined: Thu Sep 24, 2020 5:16 am
ECU Model: S40 Pro
Distributor: Watsons Wakefield

Re: Ign Advance Idle - Help

Post by Chappb »

Thanks Rob, will give it a go in a few days hopefully. I'd be grateful if you did post some settings up for reference!
Yeah the 16deg i'd read over on one of the Honda forums.....i know people are more knowledgeable over on this forum though :lol:
Thanks again.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Ign Advance Idle - Help

Post by stevieturbo »

There is no point trying to run 16deg, just because OEM do.....and you're running a totally different setup than OEM, OEM will use an air bypass...it sounds like you are not.

As rob says, you will be setting your hot idle with a relatively low timing value, so that when cold etc you can increase it to achieve a higher idle speed.

And as for any AFR changes, datalog to see what is actually changing that is causing it
Chappb
Posts: 6
Joined: Thu Sep 24, 2020 5:16 am
ECU Model: S40 Pro
Distributor: Watsons Wakefield

Re: Ign Advance Idle - Help

Post by Chappb »

True, i am lacking an air bypass....
Ah yes i'm with you now. What would be a good range to set the Min/Max limits at for the PID adjustment?

Yeah the AFR reading still threw me. How do i go about datalogging with the S40?

Thanks again chaps.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Ign Advance Idle - Help

Post by Rob Stevens »

Forget the PID adjustment for now, turn idle control off.
Try and get a good hot idle with around 5 deg ignition, you will probably have to open the throttle stop to achieve this.
Please try and follow the advise here.
The sudden change in afr is probably associated with the closed loop on/off control which is dependant on water temp and time, found in the lambda parameter menu. Or its from you lambda controller outputting 14,7 whilst it is warming up and then jumping to 10 as it starts reading correctly, check your lambda controller instructions.

Oh and confirm you timing values with a strobe light.
If you look in the real time mapping screen you will see where any fuel corrections are coming from, fuel corrections are shown in blue, ignition in orange.
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