TonyTiger2004

Ok guys, I need some help... I am totally bumfuzzled. Recently my 78 Chevy c10 with a 350 4brl starting blowing ignition coils out of nowhere. Would run up the road it would just cut out like you cut the ignition.

Further investigating i determined the Coil being shorted out.

Ok so far i have practically replaced everything!! New ACCEL Distributor Complete except coil, Has a new Starter, New Battery, new plugs and accel wireset. I have checked ground wires, ive checked the battery lead going to the cap. It measures same voltage as battery.

So today we got it running again ran it up the road and low and behold blown ignition coil once again.

SO i ask what else can i check what else could it be? it seems to be shorting out while driving down the road, Ive been through 3 Ignition modules, and 3 Coils!! Please anyone anything?

therewolf

Hi TonyTiger2004,

Welcome to the Chevy Forums.

Verify proper polarity of the coil wiring comes to mind first.

Of course, I'm assuming that you know how to apply the dielectric grease to the ECM, since you've obviously done it a few times...

How's the engine -to-firewall ground-strap?

TonyTiger2004

I have glanced over the ground strap from firewall to block, where it connects to firewall its covered with black tar type stuff thats all over the firewall, its hard to get to the bolt on the back of the block.

should i attach another ground strap to the block from firewall someplace else?

Only thing i have not replaced thus far is the ignition switch itself (the electrical part of the switch) attached to steering column. I have checked alot of the wiring with a meter.

2wd-K5

by all means clean up your grounds, if the ground strap is small or corroded when u clean up the connections i would replace it, cheap insurance

TonyTiger2004

Yeah i think im going to replace the firewall ground. Seems to me its gotta be a ground issue. Coil if burnt slap out!

TonyTiger2004

Heres a video of the Truck running before it blew yet again.

http://www.youtube.com/watch?v=OGhwl9ldNrE

therewolf

Yes, the engine ground strap is very hard to get to.

Yes, you can add a ground wire in a more accessible place. What I did was I took a 24" #4 negative cable,(available at any parts store) and bolted it from a passenger side bolt on the head(as I remember, an oil stick guide bracket bolt) to a bolt on the passenger side firewall.

TonyTiger2004

Well guys i found the solution i believe, so far so good... was a very simple mistake someone had made previously i did not catch it until yesterday.

On Some 78 chevys of this type theres a ground brack type that must go into the cap to ground out the coil to the distributor, its not been there since we've replaced the coils. Feel stupid for not noticing sooner lol. But now i got the ground bracket in the coil which grounds the distributor to the coil.

Anyway thus far its running good without blowing another coil

2wd-K5

ahh, yes not noticed if it isnt there lol