Charge time EDIS coil

JeroenBosma · Post by **JeroenBosma** » Tue Aug 01, 2006 12:16 pm

I blew my EDIS coil today while firing it directly with the coildrivers on the V3.0 board. I probably neclected the chargetime, being 4ms standard in MT.

So, now I have a coil with 0,5 ohm on one side and 0,8 ohm on the otherside. Which leaves me to 1 option, get a new one.

But, I don't wan't to fry it again.

Does anyone know what a reasonable chargetime would be for an EDIS coil ? I have read about the HEI coil whitch should be good in 2,5 ms.

Would it make sense that it fried at 4ms ?

Thanks !

Allmost there... At least it is better running then on carbs and C-breakers.. But that aint hard...

Bernard Fife · Post by **Bernard Fife** » Tue Aug 01, 2006 12:54 pm

JeroenBosma,

Typical dwell values for automotive coils are between 2.0 and 4.0 milliseconds. I don't know the value for the EDIS coils, hopefully someone who is using the EDIS with multiple VB921s can comment.

However, I thought I'd mention that there's another way to burn up a coil - if the spark output is inverted from MegaSquirt, the coil is charging when it shouldn't, and vice versa. This is bad at low rpms, as the dwell is much longer than it should be (it's not so bad at higher rpms).

However, it's most damaging when the engine isn't running at all, as then the coil is flowing current all the time, instead of not flowing current at all as it should be. So it's something you want to be sure to get right. There are hints in the MS-II documentation. (I don't know the specifics in MSnS-E, but you should recheck the documentation).

Lance.

JeroenBosma · Post by **JeroenBosma** » Tue Aug 01, 2006 2:00 pm

Thanks Lance.

Double checked the way it was charged and it should be fine.

I am running on LPG (Propane gas) and was trying to get a decent fuel constant for the injectors. So I kept it running for quite a long period while retuning the maps. I think that is what killed it.

If 2,5ms is typical, I over boosted it with more then 50%. I have learned this can be very harmfull for the unit. And to make things worse, this was an old one from the junkyard.

Better get a new one and set the chargetime to a decent value. I'll stick to 2,5ms to start with.

JeroenBosma · Post by **JeroenBosma** » Thu Aug 03, 2006 6:36 am

Ok, got meself 2 EDIS coils. So I can destroy another one

Let's see if this one will hold on on 2,5 ms and maybe get a friend to hook up a scope.

Need to buy one myself......

JeroenBosma · Post by **JeroenBosma** » Thu Aug 03, 2006 6:56 am

Started het up, but I blew the VB921. It actualy made multiple sparks into the MS housing, It sounded like that... And it produced smoke.... Well it was probably dead when I tried the new coil... The otherone on the board seems to be ok, though.... Have I missed a component ?

JeroenBosma · Post by **JeroenBosma** » Sat Aug 05, 2006 3:53 pm

Whell, installed a "new" coilpack from the wreckyard and played around with the dwell times. The odd thing: I got two Ford EDIS coilpacks and one was running on 1,1ms, but the otherone was not.

Finaly I ended up on 2,5 ms and the VB921 stayed cool and the coilpack was not warm too. So I guess 2,5ms is a good starting point and 4ms is defenetly not for an EDIS coilpack.

Good luck you all !