individual grounded coils (Homebrew ghetto rig) Remove?

[Farbin Kaiber]

So, i'm helping a friend with a 24v, his coilpacks are individually grounded, in a strange way.







What do ya say?

[bender]

i'd say i'm not even sure if thats needed.

do you ground a normal coil like that? no

[kenika65]

well it will definitely prevent loosing ground to your coils, but as long as the engine is grounded then you dont need that, just need the coils bolted down.

Someone put some time in to that.

[kronus]

Yeah, that's unnecessary unless the main engine ground is crappy or noisy. Remove it and check the potential drop between the coil pack ground points and the car chassis. If it's not zero, something is wrong and you need to check the engine ground.

Also check current draw on the battery when the car is off. If it's bigger than like 100 mA, there's a ground issue.

[nando]

overkill, but extra grounds aren't going to hurt anything.

[hoveringuy]

I thought it was strange when I wired the M54 that the coils were grounded directly through the harness, and then were grounded through a resistor to the engine.

I don't know the reason for that resistor, but it makes me wonder about grounding the coils directly!

[nando]

I bet it was for noise filtering, like resistors in plug wires.

[hoveringuy]

I bet it was for noise filtering, like resistors in plug wires.

Yeah, I'd say that's a good guess. I can definately see it on the secondary side, but the primary?

[318isbmw]

well it will definitely prevent loosing ground to your coils, but as long as the engine is grounded then you dont need that, just need the coils bolted down.

Someone put some time in to that.

Actually the 24valves have 2 grounds on the coils. I cant remember which numbers, 1 and 6 I believe? If you've got the regular grounds on the coils, I wouldn't worry about it. I guess better safe than sorry though...

[Farbin Kaiber]

Yeah, we left the OE ground straps on coils 1 and 6. they are all tied via a galvanized plate.

[1990m3]

Actually the 24valves have 2 grounds on the coils. I cant remember which numbers, 1 and 6 I believe? If you've got the regular grounds on the coils, I wouldn't worry about it. I guess better safe than sorry though...

I've found this to only be true on the obdII motors. All obdI motors I've seen only have one ground on the coil closest to the firewall...cylinder 1?