Update on my MS3, no TACH signal yet.

[Cannonball89]

I have a 1971 240z with a 1983 L28ET. I am using the stock CAS in the dizzy for my tach input and have it wired up the way the way it says to in Moby's sticky and on the DIY page: http://www.diyautotune.com/tech_articles/how_to_megasquirt_your_280zx_turbo.htm

 

I am using a BIP373 to drive the coil, and have hooked it up following the instructions here: http://www.diyautotune.com/tech_articles/using_bosch_bip373s_with_megasquirt.htm I have the V3.57 board and followed the instruction for single coil installations.

 

I had some issues with fuel leaks and my fuel pressure being way too high, but I have resolved that and am now trying to get it running. I can't seem to get any RPM indication. When I turn the key on the MS3 powers on the fuel pumps for a couple seconds like it should, but when cranking the fuel pumps won't come on, I think that is because it is not seeing an RPM indication. I used the trigger logger feature in tunerstudio and this is what it shows when cranking:

 

 

Here are my settings in tunerstudio for ignition capture:

 

 

My trigger log looks pretty messed up to me. I don't think there is any way the computer could make any sense out of that signal. Does anyone know what the trigger log should look like with the 83 CAS?nI think that is likely the problem. I'm not sure if that is noise, or a defective CAS (the motor was running when pulled on the stock ECU, so I would assume that the CAS is not defective)

 

I checked my voltage at the wires going to the CAS, the Green/White wire has ~12V, the Black/White wire has ~5V, and the Black wire is hooked up to the common grounding point on my engine block that I have all of my sensor wires grounded to.

 

Another thing I'm not sure about is that possibly the MS3 firmware doesn't support this type of CAS yet. I've seen some threads on the MS forums that they are still working on support for Nissan 360 tooth CAS's. These threads seem to be talking about the KA24 CAS's though, I have found anything directly regarding the L28ET CAS.

 

This is an interesting article on the MSextra site: http://www.msextra.com/doc/ms3/nissancas.html but I'm not sure if it really applies to the 1983 turbo CAS. I know it is optical and has a ring of 360 teeth, but I'm just not sure if it applies. I do have the V1.1 firmware.

 

So I am going to do some more research and troubleshooting and keep you updated.

[DCZ]

The 83 CAS produces 2 trigger signals, one for the 360 slot section of the wheel and one from the 6 slot section of the wheel. I am researching this for my own conversion and have not yet found (or missed reading) anything that says which signal MS uses. Could it be that you are supposed to use the 6 slot signal and not the 360?

[Cannonball89]

Using the six teeth larger inner teeth instead of the 360 small outer teeth would make more sense for a basic trigger. I too haven't found any info on which ones MS reads. All of the posts I've read just tell you how to wire it up but don't go into any detail as to exactly how it works. I have no idea how to tell which set of teeth it is reading. My log shows no consistency at all in the signal. Pretty much what I would call a garbage signal.

 

If I had to guess I would say that it reads both when working properly. I would think the log would show the six inner teeth as a taller bar and the 360 smaller teeth as a shorter bar. So basically what I would expect my log to look like would be one tall bar after every 60 short bars. But that is just a guess and it's not what I am seeing at all so far.

Edited April 20, 2011 by Cannonball89

[BLOZ UP]

You should give MS the 6 slot trigger. The CAS should have power (B/W), ground (, and the signal (G/B) connected. MS1 and 2, at least, cannot use the 360 degree part. The signal wire may or may not need to be pulled up to 12v with MS3. I'm not sure where you got your colors from. Are you going off the harness or the sensor?

Edited April 20, 2011 by BLOZ UP

[mobythevan]

The problem is that the 6 tooth wheel works for installs that use the distributor for spark. If you want wasted spark or sequential spark you need an indicator for cylinder 1. You would need a missing tooth or a different kind of trigger wheel like EDIS 36 minus 1. So if you are going to run standard spark using the distributor then the 6 tooth CAS wheel works. If you want anything else you need to tape over one tooth to have 6-1 or some other trigger wheel on the engine. Nothing that I am aware of on the 360 tooth wheel can provide location info so it doesn't help much.

[Cannonball89]

You should give MS the 6 slot trigger. The CAS should have power (B/W), ground (, and the signal (G/B) connected. MS1 and 2, at least, cannot use the 360 degree part. The signal wire may or may not need to be pulled up to 12v with MS3. I'm not sure where you got your colors from. Are you going off the harness or the sensor?

 

This is the diagram I followed when making my harness.

 

 

The wire colors I stated are on the HARNESS side of the CAS.

 

So for clarification, my voltage measurements were:

 

B/W: 12VDC

G/B: 5VDC

G/Y: Not used

Black: Ground

 

If I understand what your saying correctly, then perhaps the G/B wire needs 12Volts instead of 5Volts?

How exactly would I pull that up? With a different resistor?

[Cannonball89]

The problem is that the 6 tooth wheel works for installs that use the distributor for spark. If you want wasted spark or sequential spark you need an indicator for cylinder 1. You would need a missing tooth or a different kind of trigger wheel like EDIS 36 minus 1. So if you are going to run standard spark using the distributor then the 6 tooth CAS wheel works. If you want anything else you need to tape over one tooth to have 6-1 or some other trigger wheel on the engine. Nothing that I am aware of on the 360 tooth wheel can provide location info so it doesn't help much.

 

I am not trying to do EDIS or sequential spark, I'm just doing a basic set-up to get it running. Maybe fool around with the EDIS later. I am just trying to use the BIP373 to control my single coil and send the spark through the distributor.

 

My problem is that I can't seem to get a good TACH signal and have yet to see an RPM indication.

 

Here is a composite log of cranking that I just did, if it helps. Not sure what I'm looking at:

 

 

[mobythevan]

Do you have the v3.0 main board configured for optical trigger input?

[tvgz28]

Have you tried turning the noise filtering on?

[Cannonball89]

Do you have the v3.0 main board configured for optical trigger input?

 

It's a V3.57, and actually, I haven't checked how it is configured. I obviously have a lot to learn still. I will check that tomorrow if I have time or saturday. It looks like the optical trigger setting is essentially the same as the VR input except for a pullup resistor needs to be soldered to the pads marked R57. This actually might be the whole problem.

 

My advice, to anyone wanting to get a megasquirt, is learn to solder before you buy it and then assemble it yourself. It will give you a much deeper knowledge of how the board is configured and will save you the frustration of learning to solder anyway when you realize the preassembled kit that you paid more to get still needs to be soldered to add whatever extra goodies you need for your application. If I had it to do over again, I'd definitely be on a V3.0 board right now and would have assembled it myself.

 

 

Have you tried turning the noise filtering on?

 

Thats a good thought too. None of my other sensors show any appreciable noise, so I would be surprised if that is the problem, but it can't hurt to experiment with that after I check the configuration of my board.

[tvgz28]

Well on my 1jzgte it was doing the same thing until i enabled the noise filtering. On your composite logger the top green line is the cam input, middle red is crank trigger, and bottom is sync error i think. If the pcb was configured wrong i dont believe that you would see any signal at all. On the cas does the 360 tooth wheel and the 6 tooth wheel both output on the same B/W wire? Also im not sure if the 6-1 configuration would support anything other then batch fire due to low resolution. One more thing, when you get your trigger right you can look at the gauge screen in tunerstudios on the lower right you'll see a little indicator that says sync will light up.

[Cannonball89]

Just checked my main board, it was configured for opto-isolated trigger. It needs to be configured for the VR+pullup trigger input.

 

JP1 had a jumper between positions 2+3, I moved the jumper to positions 1+2

 

J1 had a jumper between positions 1+2, I moved the jumper to positions 3+4

 

I need to solder a 1K resistor onto the pads for R57

 

And I need to check the adjustment of the potentiometers on R52 and R56.

 

 

I hope this solves the problem.

Edited April 23, 2011 by Cannonball89

[DCZ]

I'm confused. If you are using the stock crank angle sensor, isn't that an opto-isolated trigger? Why do you have the VR+pullup trigger input setting? I read over the MS manual section for this and it is not very clear on this point.

[Cannonball89]

I'm confused. If you are using the stock crank angle sensor, isn't that an opto-isolated trigger? Why do you have the VR+pullup trigger input setting? I read over the MS manual section for this and it is not very clear on this point.

 

 

This is the page that I read this on: http://www.msextra.com/doc/ms3/ignition.html#vrv357pull

 

I'm happy to say that everything is working fine now, the car started right up after a few seconds of cranking and now I get to start the fun process of tuning!

[DCZ]

This is the page that I read this on: http://www.msextra.c...html#vrv357pull

 

Yup, that's what I read too and I was confused. So I guess the stock zxt optical pickup in the distributor looks like a VR signal to Megasquirt, and the "opto-isolator" they refer to on that page is not the same as the optical pickup. That's great that you got your car started!

 

So to recap: For a V3.57 board, driving a single coil and using the stock zxt optical CAS as input:

 

(from the link in your first post)

 

* Jumper IGBTOUT to IGN to send to IGBT ignition coil driver signal out of pin 36 on the DB37. (not needed on a V3.57)

* Cut out R57 if fitted on a V3.0 (This won't be there on my units, though.).

* Our assembled V3.57 boards, if not fitted for direct coil control, will have a jumper from JS10 to the center hole of Q16. Remove the jumper from the center hole of Q16, and reroute it from JS10 to IGBTIN.

* Solder a BIP373 into the Q16 slot, using a mica insulator.

 

Then:

 

Jumper JP1 on positions 1,2

Jumper J1 on positions 3,4

1K resistor soldered onto R57 pads

Tweak potentiometers on R52 and R56.

 

Megatune (TunerStudio) settings:

* Set Spark Output to "Going High (Inverted)." Setting this wrong can overheat the BIP373s or damage the coils.

* If using MS2/Extra, set Spark A output pin to JS10.

 

That's it for ignition control, right?

 

Keep us posted on your progress, I'm a few steps behind you and anxious to catch up!

[Cannonball89]

Yup, that's what I read too and I was confused. So I guess the stock zxt optical pickup in the distributor looks like a VR signal to Megasquirt, and the "opto-isolator" they refer to on that page is not the same as the optical pickup. That's great that you got your car started!So to recap: For a V3.57 board, driving a single coil and using the stock zxt optical CAS as input:(from the link in your first post) * Jumper IGBTOUT to IGN to send to IGBT ignition coil driver signal out of pin 36 on the DB37. (not needed on a V3.57) * Cut out R57 if fitted on a V3.0 (This won't be there on my units, though.). * Our assembled V3.57 boards, if not fitted for direct coil control, will have a jumper from JS10 to the center hole of Q16. Remove the jumper from the center hole of Q16, and reroute it from JS10 to IGBTIN. * Solder a BIP373 into the Q16 slot, using a mica insulator.Then:Jumper JP1 on positions 1,2Jumper J1 on positions 3,41K resistor soldered onto R57 padsTweak potentiometers on R52 and R56.Megatune (TunerStudio) settings: * Set Spark Output to "Going High (Inverted)." Setting this wrong can overheat the BIP373s or damage the coils. * If using MS2/Extra, set Spark A output pin to JS10.That's it for ignition control, right?Keep us posted on your progress, I'm a few steps behind you and anxious to catch up!

 

 

^^^ Great Recap^^^

 

Just for the record, it probably is possible to use the opto-isolated circuit if you adjust the pots correctly. They seem to be shipped with both pots set at the same level, if you were to turn R56 a few turns clockwise you might see a better signal.

 

Using the VR circuit is working great for me though, so I would definitely recommend it. Here is what my composite log looks like now while idling:

 

 

That looks a lot better lol. I don't know why my earlier log was showing a cam trigger as well... I don't have one. But anyway I'm glad we were able to figure this out. I need to get a driveshaft fabricated then I can move onto some more serious tuning. I will post my MSQ as soon as I feel like it is good.