Weird ignition timing at 750rpm

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.
peckhs
Posts: 12
Joined: Thu Oct 27, 2022 4:40 am
ECU Model: S40 Pro

Re: Weird ignition timing at 750rpm

Post by peckhs »

stevieturbo wrote: Fri Oct 28, 2022 9:37 am
peckhs wrote: Fri Oct 28, 2022 8:23 am
stevieturbo wrote: Fri Oct 28, 2022 3:23 am Some weird numbers in the table.

You'd need to watch the table and see what is happening and what, if any adjustments are being made within closed loop

It makes no sense to have weird numbers in one table, nevermind two.
Thank you @stevieturbo. I assume you are referring to the idle control table.. Care to explain why you find some of the numbers weird?

I think the tuner did not set the numbers in the 'Base Idle Advance' table as he select the 'Use 20 x 14 Base Duty Cycle Map' option?

I am assuming the Base Idle Advance table is the 20 x 14 Base Duty Cycle Map.

single values, random jump to 100...it's weird.

https://www.dtafast.co.uk/download_file ... Manual.pdf
I was thinking that too.. I am trying to find out why from the tuner.

The engine was built in UK, for delivery to Singapore. It was tuned on a test bench without loads, i assume. Hence i am trying to understand the maps and the parameters.
stevieturbo
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Re: Weird ignition timing at 750rpm

Post by stevieturbo »

tuning on a dyno is one thing, it will likely always need adjustments once installed in the vehicle, with the various loads attached etc.

Especially things like idle, low speed driving manners etc
peckhs
Posts: 12
Joined: Thu Oct 27, 2022 4:40 am
ECU Model: S40 Pro

Re: Weird ignition timing at 750rpm

Post by peckhs »

stevieturbo wrote: Fri Oct 28, 2022 12:44 pm tuning on a dyno is one thing, it will likely always need adjustments once installed in the vehicle, with the various loads attached etc.

Especially things like idle, low speed driving manners etc
Yes, we are going to retune on a dyno, and then do a road tune.
Currently running in the engine.
Thank you
Rob Stevens
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Distributor: None-Coil On Plug :)

Re: Weird ignition timing at 750rpm

Post by Rob Stevens »

Lambda of 1 is the default of sensor failure probably.
Get a wide band lambda hooked up to help you with the flat spot, but ask your tuner to fix first?
peckhs
Posts: 12
Joined: Thu Oct 27, 2022 4:40 am
ECU Model: S40 Pro

Re: Weird ignition timing at 750rpm

Post by peckhs »

Rob Stevens wrote: Sat Oct 29, 2022 7:54 am Lambda of 1 is the default of sensor failure probably.
Get a wide band lambda hooked up to help you with the flat spot, but ask your tuner to fix first?
We do not have a lambda sensor hooked up permanently. It is only used during tuning.

Our law disallow us to weld any bung on the exhaust, so we cannot have a permanent O2 sensor, only an exhaust tip sensor during tuning.

There is quite a few things i do not understand about the maps and tables, so as you said, i will have to ask the tuner.

It seems that during idling the engine speed is from 700-800rpm, even though the target rpm is 1000. And the ignition timing during idle on the real time info is always 25° BTDC. It does not change even when i make changes to the ignition timing at 750 rpm in the ignition map.

Not sure why he need such an advance timing at that particular rpm.

Will need to give him a call tomorrow as he rarely reply to emails..

Thanks
Rob Stevens
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Distributor: None-Coil On Plug :)

Re: Weird ignition timing at 750rpm

Post by Rob Stevens »

You will see 25deg as the ecu is trying to increase the idle speed and 25deg is the max ignition advance the idle control is allowed, this was set by your tuner. This is a not unreasonable setting.
It sounds like your throttle needs opening a little on its stop.
Once the idle control system is in action (it looks like it is) the main ignition map is disregarded, therefore you will not see any change in behaviour until you turn idle control off.
stevieturbo
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Re: Weird ignition timing at 750rpm

Post by stevieturbo »

peckhs wrote: Sun Oct 30, 2022 3:33 am
Rob Stevens wrote: Sat Oct 29, 2022 7:54 am Lambda of 1 is the default of sensor failure probably.
Get a wide band lambda hooked up to help you with the flat spot, but ask your tuner to fix first?
We do not have a lambda sensor hooked up permanently. It is only used during tuning.

Our law disallow us to weld any bung on the exhaust, so we cannot have a permanent O2 sensor, only an exhaust tip sensor during tuning.
All cars have a lambda socket these days. How old is the vehicle ?

Pretty much anything early 90's on should have it one.

Whilst crude, there are a variety of clamp on lambda options....this is one of the more expensive. Would be a relatively easy DIY too.
If you are not allowed to weld one on....this is not welded on. There are various ways to get a lambda sample without welding permanently if needed. And tip measurements at low loads are usually unreliable.

https://www.ebay.co.uk/itm/353964182100

But overall, is there an actual problem with the idle or car ? Or you just don't understand the tables ?

Was the engine tuned exactly as it would be setup and installed in the car ? or with different parts ?
peckhs
Posts: 12
Joined: Thu Oct 27, 2022 4:40 am
ECU Model: S40 Pro

Re: Weird ignition timing at 750rpm

Post by peckhs »

stevieturbo wrote: Sun Oct 30, 2022 8:24 am
peckhs wrote: Sun Oct 30, 2022 3:33 am
Rob Stevens wrote: Sat Oct 29, 2022 7:54 am Lambda of 1 is the default of sensor failure probably.
Get a wide band lambda hooked up to help you with the flat spot, but ask your tuner to fix first?
We do not have a lambda sensor hooked up permanently. It is only used during tuning.

Our law disallow us to weld any bung on the exhaust, so we cannot have a permanent O2 sensor, only an exhaust tip sensor during tuning.
All cars have a lambda socket these days. How old is the vehicle ?

Pretty much anything early 90's on should have it one.

Whilst crude, there are a variety of clamp on lambda options....this is one of the more expensive. Would be a relatively easy DIY too.
If you are not allowed to weld one on....this is not welded on. There are various ways to get a lambda sample without welding permanently if needed. And tip measurements at low loads are usually unreliable.

https://www.ebay.co.uk/itm/353964182100

But overall, is there an actual problem with the idle or car ? Or you just don't understand the tables ?

Was the engine tuned exactly as it would be setup and installed in the car ? or with different parts ?
It is a 89 Esprit, original on carbs.
I replaced it to EFI, and upgraded the engine components.
The cold idle is not ideal, and I cannot get the target idle of 1000rpm. It hovers around 700-800rpm before the water temp reaches above 80°C, after which it runs ok, with some hesitations from 2000-35000 rpm on the 2nd, 3rd and 4th and 5th gear.
The ignition timing at idle is 25°, which I think is too high.
The original ignition timing when on carbs was 10°BTDC.
I am not sure of the components in the rebuild engine, as there were some internal mods to the engine.
The engine builder is in UK, and I am located in Singapore.
The car runs, but it may not have been tuned to suit our climate.
We are going to do a on road tune to sort out the hesitation from 2000-35000rpm, but in the mean time when I am running in the engine, I would like to understand more about the idle control functions in the S40.
Thank you.
stevieturbo
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Location: Norn Iron

Re: Weird ignition timing at 750rpm

Post by stevieturbo »

turn idle control off.

adjust hot idle using the throttle and base ignition timing to around 1000rpm, with the base table around say 15-20deg

Then turn idle control on, and let it pull timing back as much as it needs to get idle back to your desired 800rpm ( if indeed that seems a sensible target )

I'd be happy letting idle control pull timing down to around 5deg to achieve this. If it is lower, then adjust throttle opening so timing is not too low.

It's a balancing act. Obviously idle control throttle position in the software in terms of off/on may need adjusted if you open or close the throttle. Also ensure 0% throttle means closed so you know where is closed, and where is not closed.
peckhs
Posts: 12
Joined: Thu Oct 27, 2022 4:40 am
ECU Model: S40 Pro

Re: Weird ignition timing at 750rpm

Post by peckhs »

Yes, i called the tuner in UK, he said the same.
So i disabled idle control, increased the air at the throttle, and voila.. Idles fine now, even with the AC and fan on! After i turned idle control ON again of course...
And yes, the ignition timing was set to 25° so it will return back to target idle faster and will prevent the engine from stalling.
He suggested that I may want to try to set the timing at 750rpm to 18°, which i will try as i drive the car more.
Thanks guys.. Your advise are greatly appreciated.
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