Couple electrical oddities, blowing out spark and alternator

[240z4u]

Alright, I am going to put these two things together in case they are related.

1) For some reason my alternator does NOT start charging normally until the RPM's hit a certain level. IE I have to crack the throttle usually. Once I have done that, it starts charging. I have 0 ga wire running to the optima in the trunk and the alternator is new, this happened on the old unit too. I am thinking bad grounding. This wasn't a problem in the past but corrosion over the last 4-5 years could be taking its toll.

2) I am blowing out spark at higher RPMS with the LS coils. New plugs. I figure this is either related to a janky ground situation or I just don't have enough power at the coils and need to install a relay and better wiring for them. The A/Fs look pretty good when this happens.

Any other thoughts here?

Thanks guys.

[WhatsADSM]

Yea sounds like it definitely could be a grounding issue. How do you have the battery grounded? How about the engine/ coils?

[240z4u]

Battery is trunk mounted with a good chassis ground (well as good as it can get). Engine is grounded to the framerails in the front. I am thinking I may just run a 4ga ground along with the chassis ground for redundancy from the trunk. Ill bet I take those ground connections apart and find rust/corrosion.

Coils are grounded to the intake manifold.

Several years of winter in the midwest can't be great for it.

Evan

[WhatsADSM]

Yea just for testing purposes it would be interesting to run a 4ga line to the back. (hell even a 10ga just to test out the theory)From the intake manifold to the negative battery terminal.

[Kevin.A]

If it's 'just for testing' jumper cable works well to ground two or more things together

you know, just for testing.

Kevin A

[240z4u]

I do have a retardedly huge quantity of black 10ga wire.

Thanks guys, now if I only had time to actually fix it.

[240z4u]

Alright, after redoing my grounds the charging goofiness is gone. I also found one plug wire was arcing through the boot. Junkass MSD wires.

I had a whopping 7 ohms resistance between the engine and chassis! I cleaned it up and added fresh grounds, grounding the coils basically right to the alternator and running another ground from the trunk (dual 8ga) and grounding directly to the block and chassis. Ill get one big ground strap between the starter and framerail and be good.

Anyway, thanks for the help. I hope the new plug wire fixes it.

[240z4u]

Alright, replaced the damaged sparkplug boot that was allowing huge flamethrower sparks to shoot out the side. All is well now.