Zmanco Posted November 6, 2008 Share Posted November 6, 2008 Recently a few times while accelerating I've felt a brief "miss", sort of like a reset but not as harsh. Today I happened to be datalogging while it happened and here's a screenshot of the log. Basically the RPM spiked to 22,374 for one cycle - you can see it just to the right of the reference line on the second panel from the top - white trace. Strangely there isn't any change in the injector PW so I don't see why the engine should loose power such that I can feel it. Everything else is running great. And it's not a reset. Has anyone else experienced this or have any ideas? Perhaps it's an artifact of the RPM Lag Factor of 40? (I suggest this knowing how the calculation is done and not seeing how it could occur.) Trigger is from a ZX turbo distributor and I'm running the MS2Extra beta code on a V3 board. Initially I thought it might be an issue with the beta code, but so far no one on that forum has any ideas so I thought I'd ask here. Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted November 6, 2008 Share Posted November 6, 2008 I have also felt that bump all of a sudden, in the motor. It usually scares the crap out of me. It happens only about once every couple of hours on average. I have never been able to catch it on datalog but it sounds like what you got. I had it with the ZXT dizzy and I still get it with the EDIS-6 system in place. I am not sure it's exactly the same as what you logged, but it sounds the same. I thought it was a reset, but it wasn't because it happend on the way to work one morning and the run-time counter on the Megaview didn't reset. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted November 7, 2008 Share Posted November 7, 2008 Could you post the full data log? I'd like to see how some of the variables not shown in the picture acted at the time of the spike. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted November 7, 2008 Author Share Posted November 7, 2008 Thanks for taking a look. datalog200811041112.zip Quote Link to comment Share on other sites More sharing options...
TrumpetRhapsody Posted November 9, 2008 Share Posted November 9, 2008 I think I may be getting this too. Sometimes at cruise it's like a stumble or cut out. I've been datalogging while it happens, and I get no indications of a reset, and nothing telling in the log. Watching intently Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted November 10, 2008 Share Posted November 10, 2008 It seems to have minor noise issues; there's also a processor reset. Based on how a few other variables changed such as Timing Error, I think that was a real bit of noise in the RPM signal. I noticed you're running beta code. If you go back to the latest stable release (2.0.1) does the problem persist? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted November 10, 2008 Share Posted November 10, 2008 What's a processor reset? Can the processor reset, without showing a system reset, or are they one in the same? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted November 10, 2008 Author Share Posted November 10, 2008 I've been running with this beta code for about 2 months and the problem only recently surfaced. Also, I'm pretty sure that cygnusx1 is running released code so I don't think it's the beta. I'd have to retune my IAC if I switched back to the released code so probably won't do that unless everything else comes up empty. Also, how did you see the processor reset? What variable is it in the log? And what does timing error refer to? Quote Link to comment Share on other sites More sharing options...
cygnusx1 Posted November 10, 2008 Share Posted November 10, 2008 I run the native 1.867 B&G code that came with my MSII. I'm not saying I have the same "burp" as Zmanco does. It sounds the same...I need more datalogging to catch it. I'll try to catch it. Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted November 10, 2008 Share Posted November 10, 2008 Processor or system reset is the same thing - the different reset is a communications reset. It shows up as a red line in the data log. Quote Link to comment Share on other sites More sharing options...
highly Posted November 10, 2008 Share Posted November 10, 2008 May be completely off track, but that log looks extremely similar to mine before I got Magnecor wires in the car. It seems like it could be an EMI issue, plug wires or otherwise. Especially with the resets while driving. On the other hand, I am new to the MS so my two cents aren't worth much. Yet. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted November 10, 2008 Author Share Posted November 10, 2008 Processor or system reset is the same thing - the different reset is a communications reset. It shows up as a red line in the data log. In the datalog I posted there were 2 known red lines - 1 where I restarted the car at a store, and the other just after the event in the screen capture which was from me hitting the space bar to mark it. Matt, did you see other resets? Quote Link to comment Share on other sites More sharing options...
Zmanco Posted November 10, 2008 Author Share Posted November 10, 2008 May be completely off track, but that log looks extremely similar to mine before I got Magnecor wires in the car. It seems like it could be an EMI issue, plug wires or otherwise. Especially with the resets while driving. On the other hand, I am new to the MS so my two cents aren't worth much. Yet. Actually I'm running with Magnecor wires. Before I installed them I had a lot of resets. Since then, except for this, I haven't had any, not even one. And I'm not sure if this is a reset or something else. Interesting thing is that I switched to the Magnecor wires a year ago but this issue has only begun to show up in the last few weeks and is beginning to occur more often. I'm not sure if something is degrading, or if I've just become more sensitive to it. Quote Link to comment Share on other sites More sharing options...
highly Posted November 10, 2008 Share Posted November 10, 2008 It is interesting (to me at least) that the 22k spike didn't seem to get acted upon (according to the other parameters) as a valid input. Quote Link to comment Share on other sites More sharing options...
Zmanco Posted November 10, 2008 Author Share Posted November 10, 2008 I'm trying to understand what the datalog variable "timing error" means and was looking at a few other datalogs. I found one with another RPM spike and noticed that the timing error hit its max of -12.7% at that exact moment. I've tried searching on the various megasquirt sites, but so far can't find any discussion of what timing error is referring to. Can anyone shed some light? Quote Link to comment Share on other sites More sharing options...
Matt Cramer Posted November 11, 2008 Share Posted November 11, 2008 There was only one reset - the other red line is a manual marking. The Megasquirt attempts to predict the next tach pulse. And it then tracks how accurate its prediction is when the next pulse shows up. That's the Timing Error readout. Quote Link to comment Share on other sites More sharing options...
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