MS3X No Crank Signal
Posted: Sun Oct 08, 2017 7:35 pm
Hi all... I'm about my witts end here.
I built a MS3X for a 2000 Miata.
I have it set up for VR, with the filters on both the expansion and mainboards set to 2.5v on the corresponding resistor (r54 on the mainboard) and the hysteresis set full ccw. There are jumpers to VRIN and VROUT, as well as a 5v pullup from VCC on the unused R13 (for the opto crank in circuit) onto the resistor below it, R45; I followed this guide https://trubokitty.com/#/ms3xassembly
I have tested continuity on my harness, as well as the entire VR circuit... The only fault I found was a lack of a ground connection via R55 to U7, and I jumped it over with a wire.
I have confirmed that I am getting 5v (I think?) to my crankshaft position sensor from the pull up...
Everything works, fans, TPS, injectors, spark, fuel pump primes, I even get a consistent camshaft signal, but I am not getting a crank signal...
Is there anything else I can do to troubleshoot what the issue is? Maybe with Q23 and Q22? I have only a digital multimeter right now, no oscilloscope... Was considering getting one, and might, if need be?
Thank you!
I built a MS3X for a 2000 Miata.
I have it set up for VR, with the filters on both the expansion and mainboards set to 2.5v on the corresponding resistor (r54 on the mainboard) and the hysteresis set full ccw. There are jumpers to VRIN and VROUT, as well as a 5v pullup from VCC on the unused R13 (for the opto crank in circuit) onto the resistor below it, R45; I followed this guide https://trubokitty.com/#/ms3xassembly
I have tested continuity on my harness, as well as the entire VR circuit... The only fault I found was a lack of a ground connection via R55 to U7, and I jumped it over with a wire.
I have confirmed that I am getting 5v (I think?) to my crankshaft position sensor from the pull up...
Everything works, fans, TPS, injectors, spark, fuel pump primes, I even get a consistent camshaft signal, but I am not getting a crank signal...
Is there anything else I can do to troubleshoot what the issue is? Maybe with Q23 and Q22? I have only a digital multimeter right now, no oscilloscope... Was considering getting one, and might, if need be?
Thank you!