MS extra siamese sequential tune (msq) to start with
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battery voltage good ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Just read this. TurboHarry had the same problem.

http://www.msextra.com/forums/viewtopic.php?f=101&t=34206

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

In that TurboHarry thread I found mention of both C31 and the VR pots.....

Both of my favourites !!!!

The standard VR circuitry is not ideal.......

I think now checking the grounding is right to stabilise the 5V supply (as Paul has already suggested) is your best starting point. Otherwise, check the 5V rail is stable inside the MS2.

Edited by Rod S on 3rd Jan, 2010.

Schrödinger's cat - so which one am I ???

Hi, I just did some more tests.
As also the fuel pump cuts out I decided to use that signal at R16 to trigger from.
I added a few plots looking at the fuel pump signal I conclude that the 5V is all right because this signal is very clean at exactly 5V. Also battery voltage is oke its 13.1V.
First plot is the VR signal at the moment the problem occurs which, as can be seen, is exactly at the negative slope of the last tooth before the missing tooth.
Second and third plot are the vr out signal Both plots confirm that the problem occurs exactly at the last tooth before the missing tooth. Last plot is the VR out signal exactly 360 degrees before the problem occurred. (Vrout1 vrout2 and vrout3 are all from one and the same trigger event the vrsignal plot is a different event what confirms that the problem always comes at exactly the same moment in the engine cycle). Could the problem perhaps be that the VRout signal is to low? As can be seen from the plots it is around 3.8V
(Engine RPM was 2000 at the trigger moment)
It could be that I forgot to calibrate the TPS sensor after I switched to the Siamese code just can’t remember so I will redo that tomorrow but I find it hard to believe that that can be the problem. Could it be that the complete system resets itself? I am running release 3.0.3h.
I read the thread of turbo Harry sounds like the same problem only mine is not related to cold weather as I am working in a heated garage and the problem stays also after the engine is heated up. All signals are using the same grounding point and all connections are new as the car is completely rebuild using new components everywhere. Never the less I will do a check on all electrical connections tomorrow just to double check.

Regards Will and many thanks for all suggestions

As the attachments again did not stick I put then on photo bucket also.
http://s758.photobucket.com/albums/xx223/g...asquirt%20Mini/

Attachments:

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Edited by gemertw on 3rd Jan, 2010.

Will,

Don't know if this will help or just confuse matters further....

I initially wondered about the 3.8V you are getting at VROUT - but U7 is an OpAmp, not a logic device so probably unfair to expect near to 5V - so I put the scope on mine...

Just running on the JimStim (fuel pump still not yet in car due to weather....)

a - as soon as I clipped the scope probe on, I got random resets - visible on the JimStim as fuel pump light flashes and IACV LEDs running to reset the idle valve, and visible in TS as RPM dropping to zero for a fraction of a second and ASE switching back on. I'm not sure how you know if it's a CPU reset or just that it's processing bad data....
However, when I connected the scope through a buffered HV probe (10:1 ratio) the resets went away (although I had to increase the scope scale by a factor of 10 to still see the output).

b - my voltage at VROUT was only 3.6V
Actually -1.7 to +1.9
That surprised me, I was expecting a zero to plus something signal (obviously I don't understand how that port works on the CPU !!!!)
But anyway, voltage swing comparable to yours.

So obviously the VR circuit is sensitive enough to be de-stabilised just by a scope probe in my case. I can't find what the input impedance of my USB one is but would assume it is quite high and although the problem went away with the buffered probe (which would be higher still) I would not have expected the plain probe to have that effect.
It was not the probe dragging the voltage down as it was still 3.6V with the buffered probe (once the correction factor of 10 had been applied).

So, having seen how sensitive the VR circuitry is, maybe your problem is something simple like a dry soldered joint or a bit of flux still on the PCB in that area ???

EDIT - as it's still below zero in my garage, I experimented a bit more.....

With the scope probe connected inducing random glitches, I turned the noise filter on on the primary tach signal and everything was perfect again :):):)

"Noise filter enabled - use noise filter curve to tune" did it, the "tach period rejection" made no difference.

I'm not sure what the filter curve is (haven't looked for it) but whatever its default setting is, worked in this experiment.

Note, though, this was purely an experiment, I've never had to turn this filter on on the actual engine but, in fairness, I've not yet had it running with all the other noise making auxiliaries.
Also I have a very high spec screened cable from the VR sensor, much better than the Ford/scrappy item.

Edited by Rod S on 4th Jan, 2010.

Schrödinger's cat - so which one am I ???

Ron,
Connecting the probes did not make my problem worse or less I tried the probes on both 10:1 and 1:1 setting (mine both have a little switch for this) both worked fine.
Did you perhaps have your scope on AC?? While measuring VRout? When I look at the circuit it can not get negative whatever the input is.
But as you said its pp level are comparable so that’s good.

I have gone minutely thru 20 complete engine cycles for both VR and VR out signal and both signals are so clean that these can not be the problem like you I also used high quality shielded cable for the VR sensor (used for measuring EEG signals).
I did not turn noise filtering on yet as I agree with you that this should only be done as a last resort objective should be to solve the problem at its source.
I have checked the following signals and they where all clean:
TPS, VR, cam trig, MAP, MAT, CLT, VCC.
I said earlier that all grounds where at the same point but I just realised that this is not true for the cam trigger. As my previous setup only had two wires connected I grounded the opto circuit to the distributor housing. Although the signal is clean I wil run a separate earth wire to it and connect it to the central earth point. The central ground is connected directly to the battery as I thought that to be the most stable earthing point.

Will

OK Will,

Yes, the scope was on AC........

My fault, wasn't looking properly

It's still 3.6V, maybe 3.65 at the most, although all positive.

I agree entirely the noise reduction feature should be the last resort rather than getting rid of the source of the problem but at least when I induced the problem artificially, the noise reduction software took the problem away.

I'm still surprised the circuit is so sensitive, ie, just clipping on a 1:1 probe in my case (but not the 10:1).

I suggest you try the noise filter just to see if it masks the problem as in my experiment. At least that could confirm if it is noise or something else ???

Rod.

Edited by Rod S on 4th Jan, 2010.

Schrödinger's cat - so which one am I ???

Hi Rod,

I will try the filter settings tomorrow before I change the grounding just to see what it does.
Just found out that tunerstudio has a diagnostic menu with a composite, sync, tooth and trigger logger I do not know what I can do with it but will just see what it does tomorrow do you have ever used this?
Regards Will

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

Dennis of which signal would you like me to post a screenshot?

With noise filtering turned on for the primary tach signal the problem disappears so this does seem to narrow the problem down to noise although all signals look very ‘clean’! Perhaps noise is induced thru the open casing? I have not run with the casing closed yet. Wil do some further testing to see if I can find out where the noise is coming from.

Will

Will,

First thanks to Denis about the tooth logger, I've never even seen it......:):):)

If the noise killer in the software removed the problem, at least we can assume it is noise...

I was really surprised when I created the problem just by attaching a scope probe - never seen it yet in all the testing I've done so far - so if the filtering works, at least you know you are looking for "noise" although the VR circuitry is obviously very sensitive.

Maybe just run with the software filtering enabled for the moment and get the other bits, ie mapping, sorted then come back to the noise problem ???

Schrödinger's cat - so which one am I ???

I wouldn't be surprised if the problem goes away with a closed case. The metal enclosure is an effective electrical shield. In any case, it should be easy to test if you still have the issue with the noise filter off and the case lid on.

Jean

http://www.jbperf.com/

a screenshot of whatever tooth timing looks erratic when the engine runs rough will be ideal, as you have a cam and crank sensor this will allow you to quicly tell which sensor is playing up. if the error is exactly the same for every crank revolution it is a mechanical problem (like warped pully, low compression on a cylinder etc) if you have two 1+1/3 height spikes where you ought to have a single double height spike for your missing tooth then you have the VR polarity incorect. if its random, its a noise, or electrical issue. when i was experimenting with odd toothed wheel patterns, i noticed the V3.0 VR circuit would produce false zero crossing events, i could never get rid of these. I had intended to try the IC based signal conditioning circuit for extra VR inputs, but decided to just get the toothed wheel froma sierra and be done with it. this error was detected by scoping the analogue input and digital output when the issue occurred, as rev's rose the sero crossing on the missing tooth was notably distorted and occationally missing. sorry i cant describe it better :( did have screenshots on msefi.com but this was many years ago, pics were on an old hard drive (now dead) .

incidently i run with my case open too.. no issues . may be worht resoldering the VR conditioner and the power circuits as a precaution. sure you will get to the bottom of it :)

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

It has been a few weeks ago since I last worked on the car.
As for the loss off synch this did not disappear with the lid closed. I just accepted for the time being to run with noise filtering on and will dive into this problem later.
At this moment I managed to get the engine to idle correctly I think due to the very big overlap of my cam, which causes a backflow in the inlet manifold at low RPM, I needed a very early injection point for the outer cylinders to get a reasonably stable and correct AFR. (I could not think of an other reason) when the timing is set between 40 and -20 I experienced a strongly fluctuating AFR from running spot on for few seconds and going very lean for no apparent reason on cylinders one and four without having misfires as far as I could hear. The cylinders two and three remained stable always.
With the 286 camshaft the exhaust valve closes 71 degrees ATDC and the inlet opens 34 degrees before TDC. The timing for the outer cylinders is at idle now 90degrees before TDC!
I think this will change a lot whet the engine gets ‘on cam’ with a carburettor this was around 3000 RPM (The carburetted engine could only take full throttle above 3000 RPM). Coming weeks I will focus on getting the car ready to get in the road to do further setup. (I still have to finish the doors and bonnet).
I added a few pictures of the car and the mounting of the megasquirt unit. I mounted the megasquirt under the dash on the passenger side and the relay board on the driver side. The relay board is mounted with hinges for easy access. The two led’s and push buttons you can see are for the LC-1 controller. From the driver and pasenger positition the units are almost completly out of sight.

Will

hi sorry to interrupt you thread but im new to this ive been trying to tune my 1998 mpi mini and have hit a wall regardless of what i do its all limited buy the ecu which sucks so i looked around and decided on a megasquirt ecu, then i found your work and everything got 100 times more complicated.
ive got an complete working mpi engine and was wondering if you guys could give me some pointers. and there's a couple of questions

1. can you use the rover cam sensor setup or would i need to set up a modified dizzy or a trigger wheel on the cams drive wheel

2. can you run the siamese code with narrow band sensors instead of wide bands i understand that i wont be able to be tell by how much the AFR's are out by but i could tell which way ( sorry project is being steered by my wallet and ingenuity )

i will add ive got buckets of enthusiasm and am good with engines

http://www.jbperf.com/

thank you Jean im gonna fit metro dished pistons to reduce compression and reduce the chances of detonation if that helps ill let you know how it go's might get a chance to test it over easter thanks for the info

I would just add to Jean's point about the Rover MPi part of the code being untested, as well as the rather strange crank signal, the cam signal comes from a VR sensor, not a Hall switch or opto-switch, so you need an additional board added to the Megasquirt to accept the signal. Those of us using a Hall or Opto-switch for the cam (on non-MPI engines) can utilise existing circuitry on the MegaSquirt board, the inbuilt MPI cam sensor needs more.

Schrödinger's cat - so which one am I ???

http://www.jbperf.com/

hummm well i was gonna fit a trigger wheel on the crank pulley because of the strange thing on the flywheel. i have a ms v2.2 board so i take it i would have to use an additional board. or is it possible to set up a trigger wheel on the cam pulley so i can use a hall or opto switch

Before going any further, is yours an MS2 ???
Not the PCB number but the CPU itself (ie, is it the plug in daughterboard with the later CPU and a few other bits on it rather than a single CPU plugging straight onto the mainboard).

The reason I ask is I've only heard of the MS2 CPUs being supplied with the later v3.0 PCB but I'm not familiar with the earlier ones so could well be wrong.

You need the MS2 CPU to run the siamese code.

Before any of us answer the other points, it would be useful to know.....

Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Edited by Rod S on 26th Jan, 2010.

Schrödinger's cat - so which one am I ???

Well, i would have thought you could get one of those hall sensors detailed above, to work with that. However, you would need to build/test it with the block on the bench.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The major differences between the V2.2 board and the V3.0 are the power supply (less rugged on V2.2), the tach input (no VR circuit on V2.2), the injector drivers (no PWM damping circuit for low Z injectors) and there's no ignition driver on the V2.2.

And as far as I know, no one provides the V2.2 with MS2 (anymore?) even though you can retrofit one without problems. However, since there is no proto area and fewer DB37 spare pins on the V2.2, you may need to be more creative on how you implement the extras from the MS2/Extra code.

Jean

http://www.jbperf.com/