Crazy readings on MS2 but not MS1 - same engine

[leonzak]

I have a MGB with a Buick 215 V8. I'm using a Holley throttle body with injectors from a GMC 1500 (60 lb from what I found out).
I have a MS1 and an MS2/extra. I loaded recent firmware into both. I am not using spark or IAC.
The MS1 is running OK (still working on the starting settings though).
The MS2 runs also but I'm getting an RPM range fo from 92 to 30,157, a Batter Voltage from 6.8 to 22.5 and other weird things when viewing with the MegaLogViewer.

The MS2 is MS2/Extra 3.4.2 release 20160421.
The MS1 is s1/Extra rev 029y4.

Because I have 4 files to upload I'll attach the MS weird one to this post and put the MS1 in a reply to this post.

Both done within an hour of each other, same engine, same car. I unplug the DB37 and RS232 adapter and plug in the other ECU. Everything else stays the same.

Any help at all on the weird readings and also what I should change in my tunings. I am running an LC-1 O2 sensor, I have it at default settings hooked to the brown wire.


thanks,
leon ...

[billr]

Post the two MSQs, also. Why two threads? That will just add to the confusion, keep everything here from now on.

[leonzak]

OK, had a problem uploading one of the files ( the file was too big), didn't realize I could post more than one at a time.

Here is the MS1 msq file. And the MS1 Log file.

Maybe I can remove the other post.

For those that may may read this and not the first one I put up a quick review - I have an MS1 and MS2. The MS1 runs pretty close to good. If I just unplug it and put the MS2 in it will run but registers weird voltage spikes on the battery volts and other strange readings. Put the MS1 back in and it's OK, no weird readings.

leon ...

[leonzak]

thanks billr, I added the Ms1 files in a reply, I could only upload 3 files.
leon ...

[Matt Cramer]

Where is the ECU grounded?

[leonzak]

ECU, O2 Sensor and relay board all grounded to the same place on the fire wall. I'll take it off today and sand/check the connections again. But - the MS1 log doesn't have the problem and I'm using the same DB37 cable - I just unplug the MS2 and put the MS1 in it's place. I would think both would show the problem.

[DaveEFI]

I have a MGB with a Buick 215 V8. I'm using a Holley throttle body with injectors from a GMC 1500 (60 lb from what I found out).
I have a MS1 and an MS2/extra. I loaded recent firmware into both. I am not using spark or IAC.
The MS1 is running OK (still working on the starting settings though).
The MS2 runs also but I'm getting an RPM range fo from 92 to 30,157, a Batter Voltage from 6.8 to 22.5 and other weird things when viewing with the MegaLogViewer.

The MS2 is MS2/Extra 3.4.2 release 20160421.
The MS1 is s1/Extra rev 029y4.

Because I have 4 files to upload I'll attach the MS weird one to this post and put the MS1 in a reply to this post.

Both done within an hour of each other, same engine, same car. I unplug the DB37 and RS232 adapter and plug in the other ECU. Everything else stays the same.

Any help at all on the weird readings and also what I should change in my tunings. I am running an LC-1 O2 sensor, I have it at default settings hooked to the brown wire.


thanks,
leon ...

First thing to do is to get a stable tach signal (RPM reading). Presumably you are using the opto input connected to the coil negative? Are both PCBs configured exactly the same? Are the basic software tach settings 'rising edge' etc the same?

[leonzak]

I have logs from a few days ago that don't show the problem. I'm going to redo clean the grounding spot and remove as many connectors as possible and then try it again. Just a bit confusing that I can change back and forth and it's only the MS2 with the symptoms. I'll check the board also for a bad solder joint.

[Matt Cramer]

Instead of sanding the connection, try running the ground straight to the battery. In my experience, even most "good" chassis grounds aren't. And a bad chassis ground....

[leonzak]

I removed a bunch of connectors. Cleaned up the ground connection - everything is grounded at the same point. Put the MS1/Extra rev 029y4 in. I've attached the log and MSQ from a run just a bit ago. It's much better I think. I would appreciate a look and any comments.

With the LM-1 & LC-1 set to defaults, the brown wire is the right one to use, correct?

MS2 update - Yesterday the MS2 turned off the high pressure pump about a half block from my driveway - I was able to roll into the garage. It doesn't turn on the High pressure pump. I checked the pump, it's working with a direct hookup, just doesn't trigger with the MS2. I have a JimSTim arriving tomorrow (thursday). I had the MS2 sitting around for a year or so since I played with it last -when I first turned it on the other day it smoked C14 - part of the injector circuit. I replaced that and it worked for a day or so then the fuel pump problem. When I get the JimStim I'll figure that one out.

Facts:
215 Buick V8 in 75 MGB. Fuel only.

[DaveEFI]

MS should supply a priming pulse to the fuel pump at switch on. If that's not happening, chances are the ZTX450 in the pump drive circuit has failed, if MS works otherwise.

[leonzak]

I did some checking and D12 had shorted - it's in the fuel pump circuit. I got a new one and replaced it and the board now works again. In the meantime I cleaned all my battery connections, new battery terminal connectors, ran a separate ground directly from the battery to the grounding point of the Megasquirt. Things are better but still have some strange things going on.

I get spikes on MS2 but not on MS1. I've attached the tunes, logs and a couple pics of oscilloscope shots I took.

Keep in mind that all I do is unplug the ms1 and plug in the ms2 - everything else stays the same. And I did these all with a fully charged battery and the alternator disconnected. Just sitting still, not driving, just started it and revved it a bit for both of them.

MS1 Battery is from 13.5 - 13.9.
Coolant temp from 186 to 197 (sitting in the garage)
AFR swings from 9.8 to 16.4
Do you see anything in the tune/log that I should change or work on? Seems like the afr has a lot of movement to me.

MS2 - Battery (again, same setup as above) goes from 13.1 to 16.1. In the osc pics it drops to 8v and spikes by 2v sometimes.
Coolant temp from 186.6 to 225.8 but that's in spikes, which it seems to have a bunch of, I'm pretty sure my temp isn't really jumping 20 degrees.
AFR is from 9.1 to 22.2

Looking at the scope pics the MS1 shows an almost 1v drop one time while the MS2 shows almost an 8v drop and an over 2v spike plus other noise. So is this normal to see this much difference between the two in the same car, same hookup? Or is there something wrong with my MS2?

I would welcome any comments on my setup please.

thanks,
leon ...

[v8fiero]

I had a similar problem on my project. Had it up and running on the v2.2 board with MS1 processor. Bought the MS2 piggyback upgrade and installed on the v2.2 board I had been using. Only changes made to the board was adding the 12V wire for the IAC stepper chip. After the MS2 upgrade I could not get a stable tach signal no matter what filter circuit I tried - Dave cap, Wing diode, etc, etc.

I recently built a schmitt trigger buffer circuit using a 555 timer chip to filter all the noise off the coil (-) terminal. That seems to have solved all my problems. I am travelling right now. Will post a picture and schematic when I get back home. If you can't wait, just google schmitt trigger 555.

[jsmcortina]

Sounds like you need to enable the noise filtering or tach masking.

James

[leonzak]

I apologize - I didn't say where the scope probe was connected. The scope images are not the tach circuit - the images are the 12v line on the relay board. That is X1, +12V Unswitched, on the relay board schematic.

The noise is being introduced on the 12v line by something in the MS2. Leaving the probe in the same place and putting the MS1 board in is the other pic with almost no noise.