stevieturbo

I tried a search, but couldnt find any info.

Im doing an install using an LS1, with an aftermarket ecu, but I need to know what the 4 wires are going to each coil ??

I can assume one is a +12v, one a -ve trigger, and one a chassis ground.

What is the 4th wire for ??

Ive had this reply on LS1 tech so far....

From Corvette fuel injection, the four wires are:
Ignition positive voltage - pink
Ignition Control Signal - light blue, purple, dark green, or red depending on which coil
Reference low - brown
Ground - black


can anyone identify what the brown/ reference low wire does or if it is neceassary.

My ecu only has the normal trigger setup for firing a coil, which is one trigger wire per coil.

Cheers, Stevie

runamuk

I'll try to remember to look up the wiring diagram when I get home

runamuk

The wiring diagram shows the brown wire going into the PCM and like you said it's labeled "low reference" so I guess since your aftermarket ECM doesn't use the low reference just cap and stow the extra wire and see if it has any affect on the coil, I doubt it will.

stevieturbo

Others have suggested its a reference ground...

I'll give both a try, and see what works


Thanks for the help...

Heretic

The driver is built into the coil. The reference wire is a separate ground for the trigger signal (probably a 5 volt square wave like GM HEI stuff) to allow the PCM to diagnose a bad coil/driver.
If you don't have a distributor, or an electronic equivalent, you won't be able to use a aftermarket ECU setup on the LS1.

stevieturbo

Can you elaborate ?

Why woud a distributor be of any use on a car with 8 coils ?

All coils I have came across before simply switch to ground to fire. ie when the trigger wire is grounded, the coil is on. When released, it fires via back emf. Are you saying these coils are totally different then ?

What about aftermarket high power coils then, that feature normal wiring methods, that would bolt onto the LS1 brackets ?