Wasted Spark ignition timing

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Coops
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Wasted Spark ignition timing

Post by Coops »

Hi guys need some help from ecu gurus as got this all wrong over 7yrs ago and want to make sure I have it correct this time lol,

Need some one to double check I have this right as like i said I got it wrong 7yrs ago lol,
yes I'm not scared to say I make mistakes :(
I want to double check the timing is still correct after removing the crank trigger and refitting after build,
I lock the ecu ignition table at fixed 10deg, mark TDC on the pulley, set timing light to 20deg due to wasted spark and start car point timing light at timing pointer and tdc should flash on the pointer showing that its at 10deg still yeah? I know about the fine tune in the ecu to get it spot on but just making sure I have it correct for checking timing on wasted spark set up????

or have I totally got it wrong again lol

Or should i really be setting timing light to zero advance, set ecu tables to 10, and lining the 10deg on pulley with the tdc pointer?

:lol:


Regards Tony C (COOPS)
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MS2 V3.57 Ecu mapable efi and wasted spark ignition.
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DaveEFI
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Post by DaveEFI »

My newer timing light - that allows you to set an advance - doesn't work with wasted spark. Had to get my old one back from my brother.
Dave
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Coops
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Post by Coops »

mine don't work with wasted spark either

just been told how to set it up.
need to make sure tdc is true first if not mark the pulley set cranking to zero advance and get some one to crank over while I use the old timing light if tdc don't line up between pulley and pointer I need to adjust the offset tooth angle until it does then reset the cranking deg back to what it is now as its ready to run off the ignition map then
sweeeeeeeeeet
Regards Tony C (COOPS)
Image
MS2 V3.57 Ecu mapable efi and wasted spark ignition.
Procharger D1SC supercharger and Cossie RS500 Intercooler @ 14psi of Boost. 416 RWHP, (boost leak)
Forged 4.8 V8 kitted out with the dogs Cajones of parts. :D
Sponsored by: www.v8performanceparts.co.uk, www.interpart.biz, www.caprisport.com & www.baileyperformance.co.uk

DaveEFI
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Post by DaveEFI »

EDIS wasted spark using an EDIS module will give you a default 10 BTDC as a limp home mode, if comms with the ECU fail. Assuming you have set the trigger wheel/sensor positions correctly.
But this would be of limited use in practice with an ECU like MS, because if you lose the comms between it and EDIS, it won't inject.

With the ignition totally derived from MS (etc) - no EDIS module - you'd normally just set the trigger wheel/sensor relationship to what the maker says by eye. As the firing point can be trimmed in software.
But by all means check it is firing where it should be with a timing light, as a starting point.
Dave
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stevieturbo
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Post by stevieturbo »

It's simple....

Either baseline to zero deg with a fixed light.....in that case it is almost impossible to go wrong

Or look for patterns. Dialback lights on wasted spark generally will read double.

So do a test at 10deg...light should flash 20.

Do a test at 20deg, light should flash 40.

That will confirm it is behaving as you expect for a wasted spark and dialback light.

If you tested at 10 and it flashed 20...then tested at 20 and say it flashed 30, then clearly something is wrong.

Or even with a fixed light and 0, 10, 20, 30 marks on the front pulley, again look for patterns.

Always check at a few different timing levels, and at a few different rpm's
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stevieturbo
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Post by stevieturbo »

DaveEFI wrote:My newer timing light - that allows you to set an advance - doesn't work with wasted spark. Had to get my old one back from my brother.
In what way does it not work ? Does it not flash or something ? The light doesnt know if it is single or wasted spark ?

Normally it will simply read and flash double...as it's just seeing twice as many sparks. ( or current spikes via the clamp )
9.85 @ 144.75mph
202mph standing mile
http://www.youtube.com/watch?v=XgWRCDtiTQ0

garrycol
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Post by garrycol »

I agree with Stevie - I have a new timing light and yes it fired each time No 1 cylinder fires so it fires so the timing marks can be read bit also fires a second time on the wasted spark fire so nothing is visible except if the wasted fire is 180 out where it does show the timing marks again.

These timing lights normally have a tacho function as well and this is where the error comes in - because of the wasted spark the rev reading is twice what it should be - so just halve the reading.

Garry

DaveEFI
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Post by DaveEFI »

stevieturbo wrote:
DaveEFI wrote:My newer timing light - that allows you to set an advance - doesn't work with wasted spark. Had to get my old one back from my brother.
In what way does it not work ? Does it not flash or something ? The light doesnt know if it is single or wasted spark ?

Normally it will simply read and flash double...as it's just seeing twice as many sparks. ( or current spikes via the clamp )
Doesn't trigger at all. On either spark plug lead of the same pair.

I can see you could get a wrong reading on one which measures RPM and the ignition is on the advance curve, But I was only really interested in checking it is correct with no ECU control - ie fixed timing. To just check the trigger wheel/sensor relationship is correct. Once you've establishes that is fairly near, you can use the offset in software to bring it spot on.

IIRC, there can be a problem with some MS/software if it is wildly out, as there is a limit to how much offset it can do.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
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