No spark, have done some things, what to try next

[aandpman]

88 K5 TBI

Yesterday morning, she started up fine, but we got 1 mi from the house and she died out in waiting at a red light. I won't go into the turmoil that ensued...

Here's what I've done/determined so far...

** Distributor was replaced 2 years ago**
Wires & plugs were replaced ~ yr ago

Have had occasional stumbling at startup for a long time now, like it was running on < all 8, then it would just clear up.

I have determined, using a spark tester:
No spark at plugs
No spark at coil

I have +12 at the input to the coil
I have +12 at the pump plug near the tank
Continuity thru the pump to ground.

Fuel pump operating when I put +12 to the test lead from the relay
Replaced ignition module - no change
Replaced coil - No change
Replaced Fuel Pump relay - No change
Replaced Oil Pressure Switch (below the distributor) no change
Cap looks good, rotor looks good

Disconnected the 4 terminal distributor connector, still no spark at the coil.

Checked SES codes using the paper-clip method, only getting code 12 over and over.

Lights all work.

The trigger magnet sucks my screwdriver to itself, so I don't much suspect that it's gone bad. I wanted to avoid throwing another distributor at it just so I can see if the pickup is bad.

That's it so far, and I'm stumped. What am I missing?

 

[aandpman]

Ironically, this happened the DAY AFTER I ordered some gears and stuff to get my front end to 3.73's to match the rear.

Go figure - maybe she read my mind and doesn't want me tinkering with her front end

 

[4xcrazy]

Check those connectors and wires going from the coil to the distributor. I had issues with mine that left it stuck at the parents house back in Indiana for two years.

Turned out to be a bad connector to coil problem, heck even Autozone sells a replacement pigtail wire for it. :-/

 

[diesel4me]

ECM fuse?..pick up coil?..ohm meter can test that..

Also a rotor and or cap can "look good" but still have a carbon track that'll send the spark to ground rather than fire the plugs,and those years seem to be more prone to that than the older "big cap" HEI's were..

 

[aandpman]

Fuses were all good, btw - forgot to post that one.

 

[aandpman]

Well - it turned out to be the pickup coil...

Pulled the dizzy and put a new pickup coil in. now she's back in the driveway....

Thanks for all the suggestions, y'all....