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

Thank for your help. So far we have changed the new gear and used VR sensor to signal the tach. There is 24 teeth and we also set the Trigger Wheel Teeth (teeth) at 24 and in order to get real RPM, we need to set the Skip Teeth (teeth) at 96. It make us confuse but good point we can run engine. See the attached msq. File.
*At moment problem, we cann’t run engine smoothly as always fluctuation in “not cranking”. At beginning we try to keep the gap between sensor and gear more closer, but problem still exist. Do you have any experience or recommend us to do some investigation?
best regard chlin

I don't think you have your engine set up properly. You say you have 24 teeth, but the no. teeth in the msq is 36, with 72 skip. Plus I don't think you want to use the dual tach sensor option with a 1 cylinder with 1 VR sensor. You probably want the single crank wheel option under dual spark option. Plus you need to tie your spark outputs together. Either tie the outputs of the bosch or vb921 drivers together, or if the coil driver takes a digital input, then put the 2 inputs through an OR gate.

In order to set this up properly in the msq, we need to know: no_cylinders, 2 or 4 stroke, verify you have a 24 tooth wheel with 1 tooth missing.

sorry i make this mistake,the cylinder number=1, 4 stroke with 36-1 teeth wheel and i try setting single crank wheel option,but i can not get the rpm display...so i must setting under dual tach option to get rpm display.
because i just want mircosquirt to control inject fuel and i do not use the spark output by microsquirt,should i tie the spark output together?
and i also have other sensors on my engine,like MAP,TPS,CLT,MAT,EGO...
i have confused with this problem 2 month. best regard
chlin

OK now we can get somewhere. Your msq for single crank wheel looks correct, but it is set up for wasted spark, so skip_teeth should be 36 instead of 72 to get the correct rpm. This will result in 1 injection every 360 deg. That should not cause any problem.

Do not attach the 2 spark outputs, just leave them floating. Also set your cranking rpm to something reasonable like 300-400 rpm instead of 3000.

If the engine doesn't run smoothly, can you smooth it out by giving it more or less fuel ? Are there any air leaks ? I looked at your datalog and your MAP reading is way low (18 kPa) and there is very little variation in it, especially for a 1 cylinder engine, so I suspect it is not hooked up. The fuel pw is set at 6.5 ms and does not deviate, so the roughness is not because the fuel is jumping around. The rpm is following the wheel, the deltaT column shows the times in microsecs between every skip_teeth. These times are jumping around just like the rpm.