TBI 454 Timing Questions

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Mh0263718

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After setting your timing, you should turn it off, disconnect the battery to reset any codes, hook up the EST bypass wire, and start it up. You're good to go!
Appreciate that brother , was really worried one will do some thing differently then the other , I got another question if you don’t mind on the same stuck , where does the hei distributed get its 12v battery reference from , when it’s spinning at cam shaft speed it’s sending battery power to the primary coil , but where does it get the power from , there’s to connectors on the ignition module on the distributer , the two wire goes to the ignition coil while the other one is a 4 wire connector , does it get power from one of the 4 wires ?
 

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Schurkey

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where does the hei distributed get its 12v battery reference from , when it’s spinning at cam shaft speed it’s sending battery power to the primary coil , but where does it get the power from
Ignition power goes to the COIL, then the wire splits to power the distributor. The distributor does not "send" power to the coil, the coil sends power to the distributor.
 

PlayingWithTBI

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where does the hei distributed get its 12v battery reference from , when it’s spinning at cam shaft speed it’s sending battery power to the primary coil , but where does it get the power from , there’s to connectors on the ignition module on the distributer , the two wire goes to the ignition coil while the other one is a 4 wire connector , does it get power from one of the 4 wires ?

Ignition power goes to the COIL, then the wire splits to power the distributor. The distributor does not "send" power to the coil, the coil sends power to the distributor.

Yes, as said, the positive wire to the coil comes from your ignition switch. Here's an example of the ICM wiring to the distributor, Pickup Coil, and the ECM. It may not be exactly like yours (it's a 7 wire diagram, yours is an 8 wire where the ground is one of the 4-wire connector) but, it'll give you an idea.
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You can look up yours here.
 

Mh0263718

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Ignition power goes to the COIL, then the wire splits to power the distributor. The distributor does not "send" power to the coil, the coil sends power to the distributor.
Not the distributer it’s self but the pick up coil inside the distributer , in other words does power start at the pick up coil , then to the ignition module , then to ignition coil primary and secondary, where it’s controlled by ground switch correct ?
 

Schurkey

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Not the distributer it’s self but the pick up coil inside the distributer , in other words does power start at the pick up coil , then to the ignition module , then to ignition coil primary and secondary, where it’s controlled by ground switch correct ?
If we're talking about SYSTEM VOLTAGE from the battery/alternator, it's switched by the ignition switch, delivered through the vehicle wire harness to the ignition COIL, and splits-off from the coil to the IGNITION MODULE in the distributor.

The pickup coil never sees SYSTEM VOLTAGE from the battery/alternator.

The pickup coil generates it's own AC power based on the magnet on the distributor mainshaft being near to the coil of wire in the pickup coil assembly, and the motion of the mainshaft specifically the inner and outer "teeth" that align and misalign as the mainshaft spins. This is the base spark-timing signal delivered to the ignition module. Below 400 RPM, the pickup coil signal directly triggers the spark via the ignition module which grounds the system voltage at the coil to cause current flow (amperage) and thus the ignition coil's magnetic field; and then the module un-grounds the system voltage at the ignition coil to cause magnetic field collapse, and thus sparks. Above 400 RPM, the ignition module sends the processed pickup coil signal to the computer, which adjusts timing advance, then sends the more-processed signal back to the module which grounds and un-grounds the ignition coil to cause sparks.
 

SNCTMPL

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Any input on advancing timing while at high altitude?
I’m at 4500’ and I always set base timing at 8-10 degrees advance. How high are you?

edit: Sorry I forgot this was a 454 thread. I was referring to a small block.
 
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