Northstar Engines and System Technical Discussion Discussion, 4 Engine Questions in Cadillac Engine Discussion; I have four main questions about the Northstar (1996 Seville STS).
What type of ignition system does my car run ...
Automobile(s): 2002.5 F55 STS, 2014 Explorer XLT 4WD
MD Eastern Shore
Re: 4 Engine Questions
Your engine uses a 4-coil waste spark system with standard emissions rated high tension wire to prevent spurious radiation of noise to onboard electronics: each coil fires 2 plugs at the same time; one plug on the power stroke, one plug on the corresponding exhaust stroke. The plug wire/coil orientation is critical to get the spark trigger at the correct stroke. Google "waste spark ignition". The two Hall crank angle sensors (CKP) are in the left side of the block, just right of the oil filter adapter, and in your engine they have the same part number. The reluctor wheel (trigger) is machined onto the crankshaft and has a series of asymmetrical teeth which act in conjunction with the Hall cam position sensor (CMP) to set timing. To figure this one out, you'll need a crank from your year engine. You cannot modify initial mechanical timing settings in a Northstar. The ICM receives ignition trigger pulses from the the PCM and sensors. There are NO moving parts save for the crank wheel. Fast Idle/IAC is a solenoid just behind and below the throttlebody and is set by engine temperature, rpm, and gear selection before idle stepdown and closed loop changeover.
For your particular ICM (Ignition Control Module) setup and possible changes contact Wester's Garage. (2000+ COP [Coil On Plug] need not apply)
Understand that these are simplified diagrams.........