Twin-spark misfires under boost - ECU power?

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.
Rob Stevens
Posts: 1128
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Twin-spark misfires under boost - ECU power?

Post by Rob Stevens »

Not sure if you undertook a coil test? this fires all coil drivers together and would show up any issues i'm sure, you could try some massive plug gaps to satisfy yourself that there is no issue.
Airspeed
Posts: 36
Joined: Tue Aug 02, 2011 2:05 am
ECU Model: S60 Pro
Firmware Version: 63
Location: The Netherlands

Re: Twin-spark misfires under boost - ECU power?

Post by Airspeed »

stevieturbo wrote: Now time to try 0 offset again !! Or 0.00000001 ? lol
Well, its certainly not too rich anymore, running pretty close to target map, so I tried 0 off-set again: Bang-bang! loud mis-fires under boost (at around 4400 RPM this time and only 0.65 bar) :|
Reset to 1 degree off-set: no problem! Not even at 1 bar I also tested with.

I did a track day last wednesday with 1 degree off-set: no problem all day (at 0.65 bar).

So, I really want to believe its not an ecu issue, but I am running out of options here..
11.06 @ 124.5 mph
'74 VW Beetle turbo S60pro
stevieturbo
Posts: 3268
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin-spark misfires under boost - ECU power?

Post by stevieturbo »

Very weird.
Rob Stevens
Posts: 1128
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Twin-spark misfires under boost - ECU power?

Post by Rob Stevens »

try 0.1 offset
Airspeed
Posts: 36
Joined: Tue Aug 02, 2011 2:05 am
ECU Model: S60 Pro
Firmware Version: 63
Location: The Netherlands

Re: Twin-spark misfires under boost - ECU power?

Post by Airspeed »

Hey guys and all that helped me: found it (last year :oops: )!

I also could not believe it would not work this way, so got back to the basics and what never had been a problem, now seemed to be the issue: I had never grounded the ecu casing itself! The casing even has an eyelet for a ground strap, but I never quite thought it to be that.
Anyways, after I grounded the ecu itself, all problems were gone... :oops: :D :D :D

Thought everyone here and at DTA deserved to know the final solution, because its an awesome product!

Walter
11.06 @ 124.5 mph
'74 VW Beetle turbo S60pro
Rob Stevens
Posts: 1128
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Twin-spark misfires under boost - ECU power?

Post by Rob Stevens »

Thanks for letting us know, glad it's sorted, must have been coincidental??
stevieturbo
Posts: 3268
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin-spark misfires under boost - ECU power?

Post by stevieturbo »

Case grounding seems to be bit or miss, some need it, some don't.

I was one of the first or maybe the first to have an issue back when the S series was first introduced around 2008 or so.

Car was terrible without the case ground, usually at low loads though. Perfectly normal with a ground added, although it was a DIY fix as cases had no ground facility then.
Airspeed
Posts: 36
Joined: Tue Aug 02, 2011 2:05 am
ECU Model: S60 Pro
Firmware Version: 63
Location: The Netherlands

Re: Twin-spark misfires under boost - ECU power?

Post by Airspeed »

Rob Stevens wrote:Thanks for letting us know, glad it's sorted, must have been coincidental??
Can't say if it was 'coincidental'. Thats usually used when we just don't know what exactly happens :lol:
If you'd ask me, I'd say that I was on the limit of what both ground terminals could manage and that grounding the case made just that little bit of a difference.
Twin plug wasted spark was probably (if I heard the comments here as well) not done that often nor in the testing, but I am speculating here. Conclusion would be: there IS a eyelet on the casing for a ground strap, probably just for these borderline users like me :lol: but its a small effort, so we better just connect it and have one less thing to worry about ;)
11.06 @ 124.5 mph
'74 VW Beetle turbo S60pro
stevieturbo
Posts: 3268
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Twin-spark misfires under boost - ECU power?

Post by stevieturbo »

Airspeed wrote:
Rob Stevens wrote:Thanks for letting us know, glad it's sorted, must have been coincidental??
Can't say if it was 'coincidental'. Thats usually used when we just don't know what exactly happens :lol:
If you'd ask me, I'd say that I was on the limit of what both ground terminals could manage and that grounding the case made just that little bit of a difference.
Twin plug wasted spark was probably (if I heard the comments here as well) not done that often nor in the testing, but I am speculating here. Conclusion would be: there IS a eyelet on the casing for a ground strap, probably just for these borderline users like me :lol: but its a small effort, so we better just connect it and have one less thing to worry about ;)
Case grounding is interference related. Not power.
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