Lost sync all at once on good system

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srb94
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Lost sync all at once on good system

Post by srb94 »

First off, here is what we are talking about
Engine:
Ford Duratec 3.0L v6 from Lincoln LS6
36-1 with OEM VR Crank sensor (3k load resistor across VRIN to ground on main board)
COP ignition
Coil Driver Box (my build using commercially available IGBT ignition drivers)
Dual Turbo installation just completed (running 5psi boost)
Larger injectors (http://www.boschdealer.com/specsheets/0280158117cs.jpg)used
Upgraded to larger fuel pump

Controller:
MS3x
Firmware pre 1.5 beta (prior was 1.4.0)
Tuner Studio v 2.6.19
Zeal board for extra Cam VR sensor input (not used, can’t to VVT with these target wheels)
Zeal now connected to replace MS3 VR conditioner with LM 1815
Knock module installed but turned off in software (Removed currently)
Wasted Spark
Semi Sequential fuel
Recent conversion from two NB O2 sensors to one WB sensor

History:

No issues observed for past couple of years, or while working on new calibration for a couple of weeks and then I started getting lost sync errors. They were not noticeable at first but looking at older logs they were there. Then they got dramatic all at once.
My first drives after adding the turbos was with the original Narrow Band configuration and VE tables with no changes just to see if everything was working and to see what needed to be changed. Car ran like Stink and we were all smiles. I did some tuning to the tables to make sure we weren’t going lean, too much spark advance, etc. with the intent of calibrating toward best torque gradually. Knock module was enabled but the signal did not look correct (didn’t increase with RPM) but hadn’t traced the problem down yet. Eventually turned it off in software and now have the module removed. Car still was great and survived several autocross days and numerous drives around the neighborhood working on other little issues on the calibration and making other changes like adding a Wide Band O2 sensor with no issues. Then two weeks ago problems started. Lost sync reason 2 with the typical RPM immediately goes to zero, cuts out, etc. all at 4000-5000 rpm. Idle and part throttle response is fine and I can rev well past this point in neutral with no issue so I am inclined to believe it is ignition noise coming in somehow but I am at a loss to find it.
Status:
At one point the engine died and would not restart. Power was on to the squirt but engine was off and it wouldn’t restart for 10-15 minutes in spite of many power cycles. I am not so sure that wasn’t a second problem but cannot confirm that point.
I also confirmed later that I could induce the problem in the shop by stabbing the throttle in neutral. However, I must basically let the engine rev to the rev limiter and don’t want to do that anymore. On one of those occasions it lost sync and the engine died with the fuel pump latched on until I turned the key off. This was different that the 15 minute period that I could not start the engine above as the power cycle immediately reset the problem and the engine restarted. At that point we decided to update firmware to the latest Beta but no change in operation was observed.
This problem makes no sense to me and after reading numerous posts on this and other forums I am now reaching out. I have had the system up and running very well for a couple of years before this problem started. There were some issues on the initial install that were traced to my error on wiring the VR sensor shield. Since then the engine has run great, but now that the chassis has been improved I needed a bit more torque (don’t we all like that) so I decided to add turbos over the winter. Let me apologize if my terminology is not quite in sync with the community, but after 30 years in the auto industry some terms are hard to change.
Data:
Sorry I don’t have a better scope with more options to better capture the data, but it serves my purpose in most cases. I used to have access to much better equipment in prior jobs but now this is what I have available. Looking at the scope traces while using the MS3 conditioner the VR signal is clean at about 5 Vp-p with a nice square VROUT signal.
(Images not inserted. i can post the word document with images inserted of scope traces, etc. but not sure if that is considered proper form.)
Sync logger confirms that it is an extra missing tooth signal.

I installed some ferrite beads on the squirt power and ground lines, spark and injector lines, and the 5vdc sensor power to try to filter out any noise I could, and there was no change. Measurements inside the squirt were as follows.
If I look at voltage drop on the ground line between pin 1 and the engine ground I can see some very faint 400-600 mV high frequency spikes lasting about 20 uSec including the ringing and decay that correspond to either ignition timing, along with a very regular 100 mV, ~10 uSec pulse every 0.4 mSec. This is similar to with the beads off but I didn’t capture the data.

I also looked at the 5v supply on the comparator of the VR circuit and found a 10 mVp-p square wave corresponding to VROUT with a 10mVp-p spike corresponding to spark, but these are insignificant in my opinion.


To summarize, here is what I have verified and tried:
1. Squirt is grounded to engine
2. Have also played with other main grounding schemes including a supplemental ground wire from battery to common ground at engine.
3. Verified all connections for VR (ground to squirt only)
4. VR line is shielded.
5. New VR sensor.
6. All sensors ground to squirt only.
7. Independent, new shielded VR cable that exits engine compartment and connects directly to squirt connector.
8. Turned off Knock module in software (car ran fine with it all enabled before but…)
9. Adjust R52 to increase hysteresis (have not adjusted R56 for zero crossing yet)
10. Updated firmware to latest beta release.
11. Removed 3k load resistor across VR sensor.
12. Added capacitance across VR sensor on main board (Didn’t help so removed it).
13. Added ferrite beads around injector and ignition lines (Didn’t help so removed them).
14. Grounded all other unused sensor lines in OE engine harness.
15. Removed a low oil pressure warning light circuit I wired in before the problem started. Not connected to squirt other than key on power.
16. Added ferrite beads to:
a. Power and ground to squirt (later removed)
b. +5VDC sensor power (later removed)
c. Spark outputs
d. Injector outputs
17. Bypassed MS3 VR conditioning in place of LM1815 Zeal board to use true differential inputs for better common mode noise rejection and any other benefits the chip offers.
18. Some other things that I have lost track of.

Thinking about several next steps including:
A. Reflowing all solder joints on all boards (scary proposition on the 3X card due to SMD components. I dont have the proper tools available
B. Power filter (doesn’t seem likely to help based on measurement of Vcc)
I’m sure I am missing something or have left something out or the problem would be solved, but I am just not seeing it. I now have given up on finding what changed, just trying to fix the problem guessing that will lead me to find what has changed and I am looking for some helpful input. I apologize if the solution is already documented, just point me in the right direction and I will look there. Unlike many posts I read, I will make a final entry if this gets resolved to help anyone else with this problem going forward. I hate to assume that the last suggestion was the one that fixed it. Any constructive comments or questions gladly received. I’m way overdue for some progress.
Steve B.
kaeman
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Re: Lost sync all at once on good system

Post by kaeman »

Have you tried using the noise filtering options in the ignition settings to see if that helps or makes the problem worse? I am using a hall sensor and have the noise filter turned off, but when I was using tach signal from the neg side of coil, I had to use the filtering to get rid of sync loss due to coil ringing feeding back and showing up as sync loss and weird rpm spikes in my datalogs.
It might be worth a try, I used the tach period rejection, because the composite log will still show the false signal, the ecu just wont count it as a real tooth.
64 el camino, 383 SBC, 11.7 to1 CR, accufab tb/rhs intake, 44lb injectors, trick flow heads, xr292r solid roller cam, belt drive camshaft, dry sump oil system, 2400 stall, turbo 350, spooled 9 inch, strange axles, 3.89 gears, dual wideband, full sequential fuel/cop, MS3x using 1.4.1 code.
DaveEFI
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Re: Lost sync all at once on good system

Post by DaveEFI »

It looks like you've exhausted all the tests I can think of, but have you had the scope on Tsel when a sync error occurred? If so, did that show a disturbance?
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Peter Florance
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Re: Lost sync all at once on good system

Post by Peter Florance »

I need to look at my Zeal board. There's a place for input resistor to ground, and some folks use 330 ohm. I've found that's too low for many sensors and can cause an extra tooth at the gap.
As can having sensor too close to the wheel.

Sent from my XT1080 using Tapatalk
Peter Florance
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81 BMW Euro 528i ESP Car
60-2 Wheel LS2 Coils, Low Z Inj
Co-Driver 1999 BMW E46 DSP car.
srb94
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Re: Lost sync all at once on good system

Post by srb94 »

All,
I attached a PDF various screens I have.

kaeman,
Thanks for the suggestion. I hadn't really tried changing the filtering at all. From what I read it seemed that it should probably be turned of unless there are known noise issues with the input signal. I could understand this when using the coil as the input but i have a dedicated VR sensor that is what Ford used on this engine. I'll have to look into this but it doesn't seem to fit my case of a tooth missing in the rest of the stream.

DaveEFI,
My scope is rather simple and doesn't have any storage or advanced triggering functions, so no I haven't but really wish i could. Since the results are the same with the board interface and the Zeal i am thinking that the issue is board level closer to the CPU, but just guessing at this point. And don't know how to approach it yet other than swapping out the whole box to confirm if it works then. But thanks,and open to the idea.

Peter,
I don't recall but will look. However, my problem is an extra missing tooth, not an extra tooth, or did i misunderstand your thoughts?
Steve B.
srb94
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Re: Lost sync all at once on good system

Post by srb94 »

Short update, and question.
Tonight, without any changes, I can duplicate the problem in neutral without load on the engine. Wasn't able to see anything on the scope during the event. TSEL looked nice and clean as did Vcc. I may have located a better scope to borrow that can digitally store the data but I need to somehow generate a trigger signal related to the sync loss event. I'm open for suggestions and doing some research between other chores.
Based on everything I have changed that hasn't affected the event I am thinking the problem is after the signal conditioning part of the circuit. The question is, is there anything else that can cause a trigger loss to occur in the microprocessor? This meaning other than the sensor, wiring, it conditioning circuit. Without that trigger I have little chance of seeing anything.
Thanks in advance for your inputs.
Steve
Steve B.
billr
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Re: Lost sync all at once on good system

Post by billr »

See how the left-most peak in the VR signal is slightly higher in amplitude? I have found that there is usually such an anomaly near the missing-tooth spot of the wave, with a VR sensor. Careful adjustment of the scope trigger level may be able to sync on that and show the wave better for a full crank revolution. Try a trigger level both above and below zero, that anomaly may peak in the negative direction, depending on "missing tooth" shape.
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Re: Lost sync all at once on good system

Post by DaveEFI »

srb94 wrote:Short update, and question.
Tonight, without any changes, I can duplicate the problem in neutral without load on the engine. Wasn't able to see anything on the scope during the event. TSEL looked nice and clean as did Vcc. I may have located a better scope to borrow that can digitally store the data but I need to somehow generate a trigger signal related to the sync loss event. I'm open for suggestions and doing some research between other chores.
Based on everything I have changed that hasn't affected the event I am thinking the problem is after the signal conditioning part of the circuit. The question is, is there anything else that can cause a trigger loss to occur in the microprocessor? This meaning other than the sensor, wiring, it conditioning circuit. Without that trigger I have little chance of seeing anything.
Thanks in advance for your inputs.
Steve
I noticed in your earlier post you said you had adjusted R52, but not R56. I've never had to adjust R52 on any of the VR sensor installations I've worked on, so leave it in the default fully anti-clock setting. But don't claim to have knowledge of every one. Or ever had to add a resistor. But it is common to have to adjust R56 - although mostly if there is no tach signal at all with a good one from the VR sensor. If I build an V3 board for use with a VR sensor, I generally send it out with R56 set 6 turns in. But looking at things as installed with a scope and set for best results is the ideal way.
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

I noticed in your earlier post you said you had adjusted R52, but not R56. I've never had to adjust R52 on any of the VR sensor installations I've worked on, so leave it in the default fully anti-clock setting. But don't claim to have knowledge of every one. Or ever had to add a resistor. But it is common to have to adjust R56 - although mostly if there is no tach signal at all with a good one from the VR sensor. If I build an V3 board for use with a VR sensor, I generally send it out with R56 set 6 turns in. But looking at things as installed with a scope and set for best results is the ideal way.[/quote]


Dave,
Not that I really adjusted things with a scope, but used the scope to verify what was there after it ran since it didn't take much. I didn't see anything suspicious early on and confirmed that things were still good after the problem showed up. Eventually not finding things lead to bypassing the whole circuit as a confirmation it wasn't the problem. That's kind of where I am. The VR conditioning looks good with two different circuits and no observable anomalies there while the lost sync event is happening, but I am attempting to gain access to some better equipment since the problem still persists. Also going to try a different Megasquirt in case it is some different area of the board (CPU, Connectors to the MS3X, etc.). That doesn't seem likely but i'm running out of ideas.
On a side note, the LM1815 circuit looks more robust than the built in conditioner. Not that it maybe is needed, but may provide more margin for noise if needed.
Thanks again for your thoughts and feel free to add if you think of something. This is really baffling me.
Steve
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

billr wrote:See how the left-most peak in the VR signal is slightly higher in amplitude? I have found that there is usually such an anomaly near the missing-tooth spot of the wave, with a VR sensor. Careful adjustment of the scope trigger level may be able to sync on that and show the wave better for a full crank revolution. Try a trigger level both above and below zero, that anomaly may peak in the negative direction, depending on "missing tooth" shape.
Bill,
Yeah, that's how I captured the trace. I had looked at it for a full revolution and didn't see anything but didn't see anything. Unfortunately it could have been covered up on the next revolution and just couldn't catch it by eye. I am trying to set up a test like that but need better equipment. Last night I had a helper I used to work with look at the scope while I was managing the engine and he didn't see anything. FWIW, his background is in VR sensor design for the OEM's so I trust his inputs, but he isn't familiar with MS. If i can devise a trigger for the lost sync and get the equipment set up we may find something, but from what he saw he feels the tach signal is good, maybe not perfect, but nothing out of the ordinary.

Also, we tried looking at TSEL and Vcc with various trigger settings, some just above or below the peak on the tach signal looking for noise during the event and didn't see anything happen.
Steve
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

kaeman wrote:Have you tried using the noise filtering options in the ignition settings to see if that helps or makes the problem worse? I am using a hall sensor and have the noise filter turned off, but when I was using tach signal from the neg side of coil, I had to use the filtering to get rid of sync loss due to coil ringing feeding back and showing up as sync loss and weird rpm spikes in my datalogs.
It might be worth a try, I used the tach period rejection, because the composite log will still show the false signal, the ecu just wont count it as a real tooth.
kaeman,
Still want to look into this but haven't gotten to it yet.
Steve
Steve B.
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Re: Lost sync all at once on good system

Post by whittlebeast »

FYI This is one of my long time friends.... like 30 years of racing. He and the wife are several time national champions in autocross so attention to detail is his strong point.

I sent him my spare MS3/MS3x squirt and a spare stim and a flashing light show board. Demon electrical is out of my wheel house so I really appreciate any help you can give him.

I hope I did not miss something stupid for him to test. The car is about 500 miles from here so I am a little handcuffed trying to help.

Andy
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Re: Lost sync all at once on good system

Post by billr »

Can you slow the scope sweep, or "parade" the wave across the screen? I would really like you to see the missing-tooth part of the wave. I have seen the lead or trail peak around the gap morph it's amplitude such that a 36-1 becomes a 36-2 as the rpm rises. I think others have seen it too (a recent thread), but it is an unproven theory...
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Re: Lost sync all at once on good system

Post by robandnoah »

I think your making this way too complicated. I appreciate your intellect but it shouldn't be this complicated. If you haven't tried adjusting both vr pots your chasing your tail... I will actually read and re-read this thread in the morning when I've slept but i can tell you, my install worked perfect for months until either blowing the motor and soaking engine harness with oil or just the ambient temp getting cold (winter). I started to a lose sync on cranking issue that got real frustrating. I ended up with maybe 2.5 turns on one vr pot that fixed everything. I don't remember which one it was, but it was the one that raised the zero crossing point above (or below) 0. Noise on VR circuit will really become problem at or near 0v crossing.
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Re: Lost sync all at once on good system

Post by DaveEFI »

srb94 wrote:I noticed in your earlier post you said you had adjusted R52, but not R56. I've never had to adjust R52 on any of the VR sensor installations I've worked on, so leave it in the default fully anti-clock setting. But don't claim to have knowledge of every one. Or ever had to add a resistor. But it is common to have to adjust R56 - although mostly if there is no tach signal at all with a good one from the VR sensor. If I build an V3 board for use with a VR sensor, I generally send it out with R56 set 6 turns in. But looking at things as installed with a scope and set for best results is the ideal way.

Dave,
Not that I really adjusted things with a scope, but used the scope to verify what was there after it ran since it didn't take much. I didn't see anything suspicious early on and confirmed that things were still good after the problem showed up. Eventually not finding things lead to bypassing the whole circuit as a confirmation it wasn't the problem. That's kind of where I am. The VR conditioning looks good with two different circuits and no observable anomalies there while the lost sync event is happening, but I am attempting to gain access to some better equipment since the problem still persists. Also going to try a different Megasquirt in case it is some different area of the board (CPU, Connectors to the MS3X, etc.). That doesn't seem likely but i'm running out of ideas.
On a side note, the LM1815 circuit looks more robust than the built in conditioner. Not that it maybe is needed, but may provide more margin for noise if needed.
Thanks again for your thoughts and feel free to add if you think of something. This is really baffling me.
Steve[/quote]

I personally know of quite a few installations using the standard V3 on board VR circuit. And there are likely many many thousands in use. Of course there will always be alternative designs to any circuit. Not necessarily better, but smaller and simpler or even cheaper. Or whatever.

Having set up the V3 VR circuit on a variety of sensor types, it's not uncommon to have no output at all until R56 is adjusted. As you turn the pot it suddenly comes good. So if yours was 'on the edge' it could quite easily give a sync loss on occasion as no circuit is 100% stable.

Now I'm not saying this is your problem, but it's the first thing to check before going further.
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

robandnoah and Dave,
Replying to both of you together since they are along the same general thought. I will definitely look at adjustments to R56, but changing the pot adjustments can also be challenging if you are debating if you turned things enough or not, which is why I substituted out an entirely different circuit to do the conditioning. The main reasons were that it eliminated any marginal components (including pot settings) with a different circuit, and the alternate circuit should provide better noise immunity. I say should only because there seems to be some debate and I don't have any prior experience with this exact circuit. The interesting result of the change was no measurable difference at all leading me to conclude that the pot settings and circuit components were not the issue.
I can respect and appreciate why the design on the motherboard is the way it is. It provides suitable input options for multiple crank sensors with simple adjustments, and it does a great job, but does introduce some problems for noise if the installation isn't well done since one of the VR legs is tied to ground, making any common mode noise signal noise that has to be accommodated. In theory the LM1815 should address this but nothing is perfect as you said.
Last night I was able to make a major step forward in ability to isolate the issue. I now have a second Megasquirt available on loan to run the car with but it was to late to do any road testing (no headlights on the car) and my day job was getting in the way. I realize that this also changes the pots. which may be a good thing. We also have changed the firmware back to 1.4.0 to match what I originally had when the problem started. The objective is to identify and isolate which area to work on since all of the obvious simple fixes had been addressed already, at least I believe that to be true, along with some outside the box attempts. Running it in the shop was encouraging in that I wasn't able to induce the problem, but I am not claiming anything until I get to drive it. Could be coincidence. If it is in the MS box I have some planned action items which include R56, If the problem still exists I have a separate list.
Steve
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

billr wrote:Can you slow the scope sweep, or "parade" the wave across the screen? I would really like you to see the missing-tooth part of the wave. I have seen the lead or trail peak around the gap morph it's amplitude such that a 36-1 becomes a 36-2 as the rpm rises. I think others have seen it too (a recent thread), but it is an unproven theory...
Bill,
Not within the capability of my equipment to capture that very well (basically cell phone photo is my storage scope). The signal looks good though. That's why I posted the picture of the sync logger in my PDF. The missing tooth isn't near the problem missing tooth at all. Observed on multiple logs but only posted one since they are essentially the same.

But thanks all of you for your inputs. Reading them all and hope to get this resolved soon. Lots of other responsibilities backing up and i really don't want to let go of this until it gets resolved, but may be forced to take a break.

Steve
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srb94
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Re: Lost sync all at once on good system

Post by srb94 »

Update:
After trying several more attempts to get VR working on the car I decided to throw in the towel and go to a hall sensor. I realize that millions of cars are running on this and my plan was to use parts conveniently available at parts stores and since that is how Ford built this engine that was my planned sensor. Unfortunately, I have one added piece of information that I don’t have documented as I should. Upon reconnecting to MS “S” I received a difference report of some parameter I was not familiar with. A quick search online didn’t help any so I accepted the values in TunerStudio. Please note that the reason I shifted away from this box was that while trying different pot settings as recommended it stopped running the car. I think it got a glitch somewhere and assumed I had done something to cause it but now I am not so sure. Maybe there is some other gremlin out there that transferred with the MSQ file to the new “A” box.
There is no reason why it won’t work, but I needed to get something happening so I decided to adapt a hall senor. Since my primary MS3X is acting strangely the borrowed one is on the car and I will call it “A”. Not finding anything to directly fit I modified a hall crank sensor to go in the same spot that was very similar dimensionally and could be modified to fit I ran out of time before I could get everything sorted out but confirmed that output with a 2k pull-up to 5 VDC gave me a nice square wave signal. My mission tonight is to try to get the engine fired but first attempts were not successful and I need to trace the signal all the way back to the squirt.
Problem needing help with:
The following images were taken with my MS3X (I’ll call it “S”) running off a borrowed JimStim. I also borrowed a light board to plug into the MS3X connector to see all the injector and spark outputs, etc. Both VR pots are adjusted fully counter clockwise. The results shown are from my original MS3X (“S”). The borrowed MS3X (“A) behaves normally throughout the RPM range, and this is a relatively new occurrence in the past few days.
The characteristics observed are that at Zero RPM there is no activity as expected. As the RPM is increased to about 700 RPM things look fine, Then the output to the light board ceases until I reach a higher RPM (1500?) where it picks back up again and looks relatively normal. I didn’t realize until looking at the tooth loggers that it really was still operating at all, but what I are several bizarre things. During this interval the pulse shows a 36-2 pattern on the tooth logger (this is on the stim remember) and there is a red band of signals on the composite logger. I have no idea what this means and am looking for some help in interpreting it and what to do next.

Does anyone have any idea what the bottom row of red inputs means on the composite logger?

I also have attached a log file of a sweep on the stim.

Thanks again for your help and inputs. I know this can be solved eventually.
Steve B.
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Re: Lost sync all at once on good system

Post by srb94 »

Any thoughts from anyone? I hvae been working on this and eventually rebuilt my msq to the same tables but starting with a new base msq and the drop out at 750 RPM is gone, but back to the same situation. I tried going to Hall input and had a nice 5 V square wave going in to the megasquirt, but don't see anything at TSEL. Tried adjusting pots to no benefit. I went back to the VR and it fires right up, but still has the sync losses at 5k rpm.
Thoughts? Suggestions?
Steve B.
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Re: Lost sync all at once on good system

Post by billr »

There have been a lot of words here, so forgive me if I am asking "old" questions.

At this point it has the VR sensor again, and starts/runs OK up to 5000 rpm, then sync-loss; is that correct? Is the sync-loss at 5000 repeatable? If so, post a new tooth-log showing that. Is the input circuit now the standard mainboard one, or the ZEAL add-on?

Since this was previously running OK, I am not suspecting a build problem like swapped or reversed pots, but posting good pictures of both sides of the mainboard may give some clues. Marginal soldering can cause problems after some time in service...
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