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No tack input at startup, trigering off points

Posted: Sat Sep 04, 2010 5:07 pm
by gvanhorn
Am trying to run MSD box from microsquirt, get good tack when reading off coil, but when set up to trigger off the points, get no INGOUT sig to fire coil. Coil is good, points good. Points are attached to 12 thru a 1k resistor. Opto + to points, Opto - to ground. Thing work great when just using the MSD. Is there a settting in code or something, doing everything in the manual. Help

Re: No tack input at startup, trigering off points

Posted: Sun Sep 05, 2010 6:58 am
by gvanhorn
Update--using o-scope have good sig from points to uS, on INGOUT I have a 5vdc pp pulse riding on a 5vref. so 5v to 10v pulse. I beleave it needs to go to 0v to charge coil. Is this a setting or is something bad?

Re: No tack input at startup, trigering off points

Posted: Sun Sep 05, 2010 8:48 am
by mxrob
I think you have to drop below something like 1.2 volts to get opto's hysteresis to switch. Have you verified your voltage pull down resistor set-up gets below this point with the points closed?

Re: No tack input at startup, trigering off points

Posted: Sun Sep 05, 2010 8:54 am
by gvanhorn
Iput on opto + is 0-8v, 0v when points closed, 8v when cranking points open, I should think this is enought to drive uS. Set up ing to run off MSD, all sensors reading good, hooked up ING1 to new coil -, put 12v on coil +, added wire from coil to sparkplug, grounded plug. With car running off MSD, got spark on plug, I get No spark on start up, only after car is running. So what is set up wrong or what is missing anyone ?

Re: No tack input at startup, trigering off points-Fixed!

Posted: Tue Sep 07, 2010 1:58 pm
by gvanhorn
After conversation with Matt at DIY, found R20 open on board, replaced, car now running on uS. awaiting custom made twin injector Throttle body. :D

Re: No tack input at startup, trigering off points

Posted: Tue Sep 07, 2010 2:28 pm
by mxrob
:D That's good news. After hours and hours of work it sure is nice to hear that engine fire up isn't it?