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
RPM Spikes then drops to zero
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If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
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RPM Spikes then drops to zero
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kjones6039
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Re: RPM Spikes then drops to zero
I'm curios here. Are you using the Opto or VR circuit for your tach input?
Ken
Ken
1979 Corvette - 383 CID SBC w/ Holley Pro-Jection 900 CFM TBI, 4-85 lb lo-z injectors & Walbro 255 pump
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
MS2 v3 w/ms2extra 3.4.0 Release
36-1, Delphi LS2/7 coils in wasted spark, driven by v2.0 logic board from JBPerformance
Spartan Lambda Sensor from 14point7
Re: RPM Spikes then drops to zero
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
Thanks
Clint
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Matt Cramer
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Re: RPM Spikes then drops to zero
I would check the grounding first. Where is the MS grounded?
Re: RPM Spikes then drops to zero
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.