megasquirt issues on m20, startup and tach. (noob....)

[535is-pa]

a buddy of mine has a megasquirt setup on his 325ix, someone else built it and installed it and presently cant figure out its issues. im a complete megasquirt noob but im very tech savvy and have built systems like this mostly for synthesizers/audio gear and pc hardware. so my buddy asked if i can help out. im sure i can but im kinda overwhelmed at the amount of info available on megasquirt.



so the first issue is on cold start, the car runs like crap and almost wants to stall sometimes requiring some throttle to keep running right.


the 2nd issue is that the tach cuts out on hard acceleration, otherwise it works fine but when quickly accelerating the tack just goes to 0.


pretty sure its just a standard MS2 setup with fuel and spark on a stock m20, it has indivigual coil packs, well 3 of them. im mostly just wondering if these are easy common issues or where i should start reading to solve these issues, its kinda hard to find direction in all the info avalable

[Scottinva]

How well does it crank? Is it firing up quickly? Does it seem to run rough right after starting, or is it happen after a few secons, will it smooth out? Chances are for that you have not well tuned warmup or after start enrichment. The best thing to do would be to take a good datalog of said problem, and post the current MSQ and well. It's good to know what version of ms2 he has, i'll help you fix it.

[turbodan]

Too much dwell can fuck up the tach. I don't know why but I've seen it before. Cold start tuning is always a bitch. Chances are it needs more afterstart enrichment and warm up enrichment. Additional accel enrichment is critical too. If you're having issues with cold running it usually needs more fuel one way or another. Its possible to be too rich, but the only way to get there is to keep adding fuel past the point where the engine responds normally and runs well when cold. That wouldn't make sense.

For reference, I use about 70% ASE, 156% AWC for EAE and 125% WUE at 30 degrees. Works great.

[marc79euro645]

data logging & then viewing the log with mega log viewer will help you see whats happening. if you are using a vr sender you may need to tune the pots(r52&r56 iirc) this is a common issue with rpm signal drops with vr senders

http://www.megamanual.com/ms2/vradjust.htm

good luck
marc