Gen1 Spark Timing Static at Part Throttle/Idle

[TexasPettey]

Does anyone know if the Gen1 spark timing advance is static at idle & part throttle or does it change based on O2 input at idle & part throttle? I know that the fuel map changes with MAP/IAT/TPS/O2 inputs, but does the timing advance?

 

[GTS Dean]

Chris,

Not fully certain, but reasonably sure that timing & fuel are adaptive within a parameter block map, and also linked to O2 sense. Oxidation/reduction cats work by varying IPW (rich/lean) to maintain proper temps in the catalyst bed. Since you have OBD I, I'm not sure how cat efficiency is monitored. That's what downstream O2s are for in OBD II (JTEC). THere are a lot of things going on in there. Read the manual - it's been way too many years for me.

Also, I would strongly urge you to consult with Dan Cragin. He makes these things work in Kali.

 

[Jack B]

Does anyone know if the Gen1 spark timing advance is static at idle & part throttle or does it change based on O2 input at idle & part throttle? I know that the fuel map changes with MAP/IAT/TPS/O2 inputs, but does the timing advance?

Timing/advance is part of the idle control via the pcm. In addition, timing is constantly changing depending on multiple factors, but, primarily is controlled by the MAP value and rpm.