no RPM when cranking

[cam1113]

hello, All


I am new to this so I am still learning here... I have A aircooled VW with A 2110cc engine with a pertronix ign and coil...I got the engine to run for about 45mins. and then the engine shut off and now it will not restart I am getting good spark off of coil and the car tac is moving. but the tac on the "tunerStudio" will not show RPM most of the time. it will show RPM every now agin and the engine will try and fire for a short time maybe a sec or two...I have bin reading posts and can not seem to find anything close to what I am working with... so if there anyone out there that can shead some light on this for me please help...

I am using the microsquirt
using pin 30 option + to the - side of the coil
using pin 31 option - to a 12 volt source
to trigger the microsquirt

[Matt Cramer]

It's possible you may have burned R20; check its resistance with a multimeter.

[cam1113]

ok thanks I will check that and should I read on the meter....
How could it burn out?
could it be the tac signal it self?

thanks craig

[Matt Cramer]

I've seen it overheat from particularly high voltage coil pulses before.

[cam1113]

ok I checked the R20 resistor and I am getting about 1.534 Ohms on the meter.... so what can I do to help from burning it out when I replace the resistor??? Dont what to be replacing them every 45 mins like I send I am still learning... Thank all for your help

[Matt Cramer]

Try running a 10K resistor inline with the Opto In +.