ignition coils

[9873Dennis]

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?

 

[Vbb199]

Is the motor grounded good? There should be a ground from battery to motor.
The distributor grounds to the motor.

You mentioned ignition modules being replaced thrice, 1 time at the end of the post
Whats the story there?

 

[Ricko1966]

To check engine ground put 1 lead of your volt meter on the negative battery post,put the other lead on the block. With the engine running see how many volts your meter is pulling. If more than 1/4volt redo your ground. If you haven't redone the big three grounds you might as well. Ground battery to engine ground battery to core support daisy chain engine ground to frame. That's just one way,the basics is frame has GOOD ground body has GOOD ground, frame has GOOD ground. Engine has most draw so first ground the others can daisy chain from it. Volt drop test I told you at start of post,do same thing on your positive battery lead,who knows maybe you are dropping voltage there. It is the same test except use battery positive and big lug at starter. You'll probably have to make a jumper because your leads won't be long enough. Allow an extra .2 volts for the 2 jumper connections.