I've had my microsquirt for over a year now on the car (94 mustang). For the most part, i think the tune is pretty good (except idle but thats another topic). for the past several months Ive been having an issue i cant figure out. The rpms will drop to zero briefly, like for a split second. It doesnt show up on the data log, but i can see it on the factory tach. It only happens under part throttle cruise and usually when the car is warmed up. would someone please look over my tune and see if im missing/forgot something?
The datalog and tune file are either not from the same car or some kind of ign table changes have been made. I can see in the datalog the ign values are different. I see no issue with the RPM signal into the MS from the log file. IF the car does not feel like it is dying when this event happens, then i would suspect something in the tach circuit... does the ecu feed the tach in your installation?
It appears the tach is fed from the negative side of the coil just like on a fox. Can you feel the RPM drop in the engine or is it just a phenomena with the tach? If its just the tach then i would assume that the issue is either the tach itself or the wiring
I am seeing normal behavior from the idle valve based on the provided tune. The pip signal looks clean on the input side and i do not see any sync loss errors in the log file.
What i do see are lean spots in the tune as you transition into new gears and come off idle, that will make the car stutter. I do not see anything rpm related on the datalog that coincides with the RPM signal dropping out however
FWIW, i found the issue. I have an inverter in the car to keep my laptop charged. Its a 400/800 watt model wired directly to the battery with a 50a fuse. When i have the inverter on while the laptop is on/hooked up to the microsquirt, thats when i have the aforementioned issues. With the inverter off/not charging=no issues......go figure