High boost misfire VEMS and LS coils

[A80Avant]

Thanks jade

Maybe i sould just run my car at higher dwell settings.

Only thing about that i don't like is the fact that my car was running flawlessly on the old settings and now i have to double the dwell time to get no misfire's.

How could that happen? Only thing i can think about is that the coil with the weak spark is defect and can now only perform right at high dwell settings. But can thees coils go bad when not used

Mine are 2.5ms and 20

As you say before changing settings just change sequentially the coil cable and then the coil if it still misfires. I had a loose spark plug which ate the coil cable. Thankfully it doesn't misfire anymore and I didn't have to change the coil itself

[V6quattro]

Thanks jade

Maybe i sould just run my car at higher dwell settings.

Only thing about that i don't like is the fact that my car was running flawlessly on the old settings and now i have to double the dwell time to get no misfire's.

How could that happen? Only thing i can think about is that the coil with the weak spark is defect and can now only perform right at high dwell settings. But can thees coils go bad when not used

[jade]

Just checked mine 4.99 ms & 4

[V6quattro]

I'll double check and let you know tonight. I do have the dwell at 20 I think. I get a validation yellow alert but ignore it as per Marc's advice.

as in 20ms dwell time? Is that not really high?

I also have a yellow alert as you can see.

[A80Avant]

I also had my set from marc @efiexpress. Was perfect for 5000km but with my new loom i have misfire's. At what dwell and charge time do you have your coils?

I'll double check and let you know tonight. I do have the dwell at 20 I think. I get a validation yellow alert but ignore it as per Marc's advice.

[popdemonic]

if you purchased them from Marc.don't worry about them.he always stand behind his goods.

[V6quattro]

I got everything from Marc and they have been fine.

I also had my set from marc @efiexpress. Was perfect for 5000km but with my new loom i have misfire's. At what dwell and charge time do you have your coils?

[A80Avant]

I got everything from Marc and they have been fine.

[V6quattro]

FYI,i have D514a coils for many years.they're almost the first batch of running
LS2 coils conversion.Previously,i had D585 coils from EFIexpress and finally sold
to a guy locally.both sets is still running flawlessly.one thing i noticed now we got
a chinese knock off coils available in the market and they're harder to be justified
if they're genuine or Reps.some of them has a reliable quality but some of them
is trash.

Do you think it is best to order a genuine set at the dealer?

[popdemonic]

FYI,i have D514a coils for many years.they're almost the first batch of running
LS2 coils conversion.Previously,i had D585 coils from EFIexpress and finally sold
to a guy locally.both sets is still running flawlessly.one thing i noticed now we got
a chinese knock off coils available in the market and they're harder to be justified
if they're genuine or Reps.some of them has a reliable quality but some of them
is trash.

[V6quattro]

So as you can read i played with the car today.

I made a movie off the coil test en noticed the coil for cylinder one is weak. Its really noticeable when i set the charge time and dwell at 1. Coil 1 is weaker than all the others as you can see in the movie. At my original settings and when i set the dwell at 5ms its less noticeable but still not good.

I have put the charge time at 1 and the dwell at 5 and now the cars runs nice on high boost. But to be sure i will order 5 new coils at jfetech.nl

[V6quattro]

since you drive a car and normally the tips could start to corrode that's why you
might need to regap them again especially running under high boost.i found the
copper plugs is prone to be faster corroded than iridium's.my NGK's Iridium started
to misfire under 23psi after 10,000kms.i decided to regap them down to 0.4mm iirc.
you might try to incerease your coils charge time since it's much easier than pulling
those spark plugs off but be careful on toasting your coils if you increase too much charge time.

First thing i did was putting new plugs in gaped at 0.5mm and sadly that didn't help. I did increase the charge time today and the car runs perfect now. I only don't like the fact that the car was fine for 5000km and now i have to adjust the charge time a lot to let it run right.

[popdemonic]

since you drive a car and normally the tips could start to corrode that's why you
might need to regap them again especially running under high boost.i found the
copper plugs is prone to be faster corroded than iridium's.my NGK's Iridium started
to misfire under 23psi after 10,000kms.i decided to regap them down to 0.4mm iirc.
you might try to incerease your coils charge time since it's much easier than pulling
those spark plugs off but be careful on toasting your coils if you increase too much charge time.

[A80Avant]

I have that set at 20 at Marc's suggestion for the LS2 coils.

[Mcstiff]

F1 is your friend:

Coil Charge Time MAP Scale
Dwell is extended by (MAP - 70kPa) * Coil Charge Time MAP Scale/4096, but no more than +0.4 (40% extension that is *1.4).
Examples:

0 : no dwell extension at all (neither voltage nor MAP based): Coil Charge Time @13.2 is used. Mainly used to set at fixed pulsewidth for external ignition amplifiers (CDI or smart coils).

1 : The recommended value, only voltage based dwell extension (max *2, when voltage is at or lower than 7 Volts).

2 : 40% reached at 890 kPa, and 1.5% at 100 kPa.

3 : 40% reached at 616 kPa, and 2.2% at 100 kPa.

5 : 40% reached at 400 kPa, and 3.6% at 100 kPa.

10 : max dwell-extension +40% reached at 234 kPa because (234 kPa - 70 kPa) * 10 /4096 = 0.4. This is a lot of extra charge time! Take care if using a higher setting than this.

20 : max dwell-extension +40% reached at 152 kPa because (152 kPa - 70 kPa) * 20 /4096 = 0.4

values 2..255 : Battery voltage based extension is automatic. Slope of MAP-based dwell-extension is configured with this variable. MAP-based extension is max *1.4 (+40%), while total scaleup (vbattmultiplier * mapmultiplier) is max *2.

Do not use values higher than 20, as this is likely to overheat/destroy your coils.
Higher value means higher slope (so max dwell extension reached earlier). Take care not to overload the ignition output or the coil (use lower Coil Charge Time @13.2V so you only get extended dwell when really necessary).