11-23-2011, 07:27 PM
Join Date: Aug 2009
Location: Lake Jackson, TX
Total Cats: 2
97NA MS1 Parallel Install - How can I stabilize my tune for temperature changes?
I have a basically stock 1997 1.8L NA with an MS1(pcb3) installed in parallel. It is set up in the standard configuration but with Joe Perez's improved spark output circuit. CLT sensor is a dedicated GM unit mounted at the back of the engine next to the OEM sensor. IAT sensor is a dedicated GM unit dangling inside of the stock intake box snorkel.
I've got a pretty close emulation of an OEM spark map and I've used VEAnalyzeLive to flesh out what seems like a reasonable fuel map. Currently accel enrichments, ego correction, overrun, baro correction, and launch control are all turned off. CLT-related air density is set to 100% across the board with "normal correction" selected.
The car seems to run well as long as IATs are between 73-83*F and coolant temps are between 185-198*F. Driveability is pretty good and AFRs seem to be where I want them most of the time. However, outside of these temperature ranges, the AFRs seem to go haywire and the car tends to run roughly as a result. The car seems to idle fine most of the time when the above temperature conditions are met, but occasionally it seems to surge/hunt and run a bit roughly. When the above conditions are not met it idles very roughly.
What steps do I need to take to stabilize my tune to work properly under a wider temperature range?
I can take some datalogs if that will help diagnose my issue(s), but I'm not sure under what conditions to log?
EDIT: I have attached a copy of my .msq in case that would be helpful.
Last edited by jnshk; 11-24-2011 at 12:39 PM.
Reason: Added MSQ and more details