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.

 

Anyone got any ideas? I'm inclined to think that my problems are originating from the IAT sensor/calibration/heatsoak, and/or from the CLT-related air density tables. Not entirely ruling out the spark map either though, as most people seem to be using the mspnp base map configurations and not running into issues like this.

Or is there something else obvious that I've missed?

EDIT: Or could it be something emissions-related that the OBD2 computer is doing that is affecting what the MS is trying to do?

 

(Sent from phone via capitalism)

Try to clt-based curve that's on the 9093below basemap

 

Thanks for the input, Brain! So it seems most likely that it's an issue with the CLT-curve?

I will give the mspnp9093 curve another go. This time I'll be sure to datalog things each step of the way.

 

Just curious, how did this work out for you?

 

I haven't had a chance to try it yet. Work has been abnormally hectic for the past month. :( I will definitely report back once I have time to play with it again.