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

I am running an MSII pcb 3.0 with an 8 pin small cap HEI on a SBC 350 with TBI. It's been running for a few months and everything is working great except for the engine will randomly cut out. I drive the truck to work every day and it may happen once a week, at different times and different conditions. I finally managed to have my laptop logging when it did it, the RPM will spike then drop to zero and then return to normal. I think I have a ground issue or maybe a bad module, but I'm not sure. I would appreciate any incite you guys may have. I'm attaching the log

Thanks

I'm curios here. Are you using the Opto or VR circuit for your tach input?

Ken

I'm running it through the Opto circuit, I also added the mod described in DIY Auto Tunes site for the stronger RPM signal with HEI. It hasn't done it again since yesterday morning. I'm still running to B&G code but I'm planning on uploading MS Extra just haven't had a chance.

Thanks
Clint

I would check the grounding first. Where is the MS grounded?

It was grounded to the block at the same location as the battery cable so I moved it to a different location on the block. While checking the wiring I found that I hadn't stripped the shield wire back far enough on the tach wire, and it may have been making contact with the center conductor. I haven't driven it much but the sensor logs seem to be much smoother.