What exactly does the ECU do

[tparker]

OK, my ignorance is showing here. LOL. But what does the ECU actually do? Probably something obvious I should know, but I'm at a loss. And I am assuming it isn't needed for electronic ignition, correct?


Thanks

[Burdar]

With points ignition...
When the points are closed, electrical energy flows from the battery to the coil to ground.  A magnetic field is created in the coil.  When the points open, the ground is lost.  The magnetic field collapses and a spark is sent to the point of least resistance...the distributor.


With electronic ignition...
The pickup coil in the distributor sends a signal to the ECU.  The ECU opens the circuit to collapse the magnetic field.

[Skdmark]

Article on it.

http://www.fourforty.com/techstuff/ignition.html

[tparker]

OK, Thanks. So I wasn't as off as I thought. However, I assumed the 70 challengers had points AND the ECU. Mine had a Mallory electronic distributor so I didn't have to mess with points and it's been a while since I tore everything down. I'm reviewing stuff as I put it back together. 

OK, I see now, I think. I was looking at this diagram in the tech section https://www.e-bodies.org/Resources/TSB/Electronic_Ignition.pdf and closer review said this was a change in 71. I missed that part, guess I should read the words instead of just the pics. LOL. So, originally the 70 Challenger, and Cuda(?), didn't have electronic ignition or ECU.

[Chryco Psycho]

Only points in 70 & 71 no ECU