MicroSquirt.com read only forum (Jan.15,2018)

How much should a map sensor fluctuate and how much does that effect tuning? My map sensor fluctuates about 10 kpa at pretty much all rpms. I have installed a fuel filter to act as a canister and also an inline restrictor but nothing seems to help. I also must note that this is on a V-twin Briggs motor that has a governor so that it can't rev past 3850 rpms. So at full throttle no load the butterflies are not fully opened. I have the motor running pretty good everywhere except at full throttle no load, it has a miss and I can't seem to smooth it out.

It is totally normal for a vtwin map to fluctuate. The pulses on vtwins are very dynamic. It will not effect tuning at all.

The only way to get rid of it is adding about 8 or 10 psi of boost. That will flat line it at max boost. No resevoir will help.

If it bothers you to see the engine jump cells, you can set the map bins more than 10 kPa apart. Or use Alpha-n.

Or if the engine rpm flucuates, make sure the neighbouring cells are fairly close to each other / no big jump in ve number. It sounds like just a tuning issue. Not the map sensor looking like a sign wave.

I will agree that it is a tuning issue. This is my first experience with the microsquirt so I'm still learning alot. I will adjust the map bins to be greater than 10 kpa and see how that helps. Thanks for your response