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baggedgoods

Megasquirt ignition and timing problems

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So I found this on the Megasquirt website for controlling spark advance with an optical sensor distributor(what my car has). http://www.megamanual.com/ms2/Bosch_124.htm

Now, would I hook that up directly to my ignition coil? Or would I hook it up to my power transistor? The power transistor is also known as the ignition module, and I've read that people with Megasquirt for 300zx's have gotten their cars to run fine without the PT.

MS Extra should have it's own built in Coil drivers ( BIPS373 ) . Since the car runs, it obviously has them installed. You don't need an external Coil driver or module.   I think you should be heading over to the Mega Squirt forums and seek more help there. Huge amount of info there.

 

BTW, some advice. You said you haven't tuned your Fuel Map yet. In that case make your Ignition Timing Map VERY conservative. Limit maximum mechanical advance to 28 - 30 BTDC.

 

Idle advance of 10 to 12 degrees maximum ( with stock Camshaft ) . 15 Degrees maximum idle advance with a Stage1 or Stage 2 camshaft . DO NOT ADD ANY EXTRA LIGHT LOAD ( Vacuum Advance ) ADVANCE. The last thing you want is too much Ignition advance and then run into a lean spot on the Fuel Map .

 

Once you have your Fuel Map tuned and AFR's all sorted on (preferably ) a Dyno, then start fine tuning your Ignition Map. Of course you are running a Wide Band AFR meter... correct?

Edited by Chickenman

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Yes I am running a wideband afr gauge. After every adjustment I make, I make sure to press burn every time. That picture was only for the sake of showing my ignition settings. I just don't understand how my timing is not being set by megasquirt. I've tried mechanically setting my timing to 0° and using the fixed advance at 10 or 15°, (clicking burn) and my timing would still be 0° at the crank. Edit: I've adjusted the trigger offset while doing this and I still have no success. I bought a pre built MS2Extra with the 3.3.0 firmware (if that's any help). I've read through a bunch of articles and posts about rotor phasing, and I don't really get the jist of it.

 

I really appreciate the help.

Edited by baggedgoods

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Looking at your screenshot of " Combined Ignition Option " in post #7 I think you have it configured wrong.

 

1: Spark Mode should not be " Basic Dizzy "

 

That affects all other settings and many of them are Greyed out, such as  " Use Cam signal if available ". You need a Trigger ( Crank signal ) and a Cam signal ( Home signal ) to enable using Programmable Ignition Timing.

 

The way you have it setup according to that screenshot on post #7, the ECU thinks you are running a regular Distributor with Mechanical Advance weights and a Vacuum advance Pot.

 

I'll have to check the MS software... But you should have a Pull Down Option to to use Nissan Z31 trigger wheel. But it's 2:00 AM and I'm going back to bed....

Edited by Chickenman

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OK... Go read your Tuner Studio Manual. You have your Ignition Trigger settings wrong and a MS2 ECU needs a special trigger wheel for the Nissan 300ZX Dizzy.  An MS3 apparently can support the stock Nissan Z31 trigger wheel, but the MS2 cannot. 

 

Read the following link and purchase the DIY trigger wheel described . Make sure you read the WHOLE article, as there is very important information contained within, and you may have to make some Hardware changes to your MS2 board ( if they have not already been done )

 

https://www.diyautotune.com/support/tech/hardware/nissan-trigger-disc/

 

 

Without installing Tuner Studio on my PC ( Now 2:35 AM ) I don't have all the options available in front of me.  Edit: But below  is my best reckoning by reading the TS User Manual are the recommended settings by MS when using their special Nissan disc.

 

Note: Many of the below sections are currently " Greyed Out " because you have the Main Spark Mode set wrong.

 

Once you have the new Trigger wheel installed, the following settings should work:

 

TunerStudio settings (Batch fire / wasted spark or single coil)

  • Settings under Basic Setup -> Tach Input / Ignition Settings:
    • Spark mode: Toothed Wheel
    • Ignition input capture: Falling Edge
    • Spark output will depend on what output setup you’re using. BIP373s and QuadSparks both use Going High / Inverted.Getting this setting wrong can damage the ignition module and/or coils. If the ignition module or coils get hot with the key on and the engine off, turn the key off immediately and select the opposite output setting.
  • Settings under Basic Setup -> Trigger Wheel Settings:
    • Trigger wheel arrangement: Single wheel with missing tooth
    • Trigger wheel teeth: 12
    • Missing Teeth: 1
    • Tooth #1 angle: 345 (This varies slightly between individual engines. Check with a timing light and adjust as needed.)
    • Wheel speed: Crank wheel

TunerStudio settings (Sequential coil on plug and / or sequential fuel)

  • Settings under Basic Setup -> Tach Input / Ignition Settings:
    • Spark mode: Toothed Wheel
    • Ignition input capture: Falling Edge
    • Spark output will depend on what output setup you’re using. BIP373s and QuadSparks both use Going High / Inverted.Getting this setting wrong can damage the ignition module and/or coils. If the ignition module or coils get hot with the key on and the engine off, turn the key off immediately and select the opposite output setting.
  • Settings under Basic Setup -> Tach Input / Ignition Settings:
    • Trigger wheel arrangement: Dual wheel with missing tooth
    • Trigger wheel teeth: 12
    • Missing Teeth: 1
    • Tooth #1 angle: 345 (This varies slightly between individual engines. Check with a timing light and adjust as needed.)
    • Wheel speed: Crank wheel
    • Second trigger active on: Rising edge

 

 

Trigger Wheel settings are critical. I would highly suggest that you go to the Mega Squirt Tuner Studio forums to get the EXACT configuration. But give these settings a try first and post back with results. Take a new screen shot of  your re-configured  " Combined Ignition Options " .

 

I think this will get you headed in the right direction..

Edited by Chickenman

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It takes a large amount of research and a steep climb on the learning curve for the MS. Each vehicle having it's own path. It WILL click soon enough if you stay at it. My experience is with MS3 and no dizzy, so it would take me lot's of studying to get where you are.

I would suggest getting on the MS forums, buy someone a starbucks by donating to the forum and  go from there. Make sure you can upload your settings in your thread and then be patient. Don't expect an immediate answer , but sometimes a direction to go. Take your time and write your question in much detail.

I would say that since the car runs, you have a HUGE start on your conquest. There seems to be many issues with losing communication with rpms. I believe it's just a setting-ask me how I know :) 

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Yes, it is a definitely a steep learning curve. I'm glad I setup my HalTech system on a bench tester before installing ( still some time away ). This enabled me to get used to the system, generate some off line Maps and find out some of the " quirks " in the software. 

 

I swear to God they must have had multiple Programmers making the software as some things make perfect sense and are intuitive, and then there are sections that seem to be designed by the " Cookie Monster ".

 

For MS, at least the OP has one of the most knowledgeable and active ECU forums on the planet. Thanks to the DIY philosophy and " Open Source " .And they fully support all of their older products.

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Yes I am running a wideband afr gauge. After every adjustment I make, I make sure to press burn every time. That picture was only for the sake of showing my ignition settings. I just don't understand how my timing is not being set by megasquirt. I've tried mechanically setting my timing to 0° and using the fixed advance at 10 or 15°, (clicking burn) and my timing would still be 0° at the crank. Edit: I've adjusted the trigger offset while doing this and I still have no success. I bought a pre built MS2Extra with the 3.3.0 firmware (if that's any help). I've read through a bunch of articles and posts about rotor phasing, and I don't really get the jist of it.

 

I really appreciate the help.

Sequence of events when setting parameters may matter.  Seems like you're taking all of the right steps.  Here is DIYAutotune's recommended method - https://www.diyautotune.com/support/tech/other/base-timing/

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Wow, I really appreciate all this advice. I had planned on dropping a thread at the msextra forums but I haven't had my tuning laptop lately with my logs and tunes. Once I get it, I'll be posting there. As for now, I'm going to wait till it's a bit nicer out. I will be trying your guy's recommendations and I will post whether I have any progress or setbacks. Thanks a bunch guys, I want to hit the streets soon with the beast!

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So I have ordered the new trigger wheel and will update further on it. I have a quick question, would I need to phase my rotors before I install the new wheel? If yes, what's the simplest way to accomplish that? I'm still a little lost on that whole thing. If no, then we're all good.

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What I have done is ordered an extra distributor cap. You drill a hole on top of the cap at #1 Terminal so you can shine the timing light through and see where the rotor is firing in relation to the terminal.

 

You should then be able to adjust the distributor body and adjust the trigger angle to keep the spark aligned with the tip at minimum advance and maximum advance. I don't think you can change the position of the actual rotor on the Z31 dizzy. Our setup is not the same as what MSD shows in their video's of phasing with a two piece adjustable rotor on Chevy's and Ford's. You'll have to play with things a bit.

 

You may not even have to phase things at all, as Nissan has probably already designed the correct phasing in the Optical Dizzy. The Chevy and Ford dizzy's shown in Rotor phasing articles and video's were not originally designed to be used with an ECU controlling the timing curve. The Nissan Optical dizzy's are. I'd recommend setting the Dizzy up initially with it bolted down in the center of the slotted mount holes on the Dizzy base. Then you can adjust either way...if needed.

 

The spare Dizzy cap with the hole drilled at #1 terminal just makes it easier to check when running.

Edited by Chickenman

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Moby implies that the 83 wheel will work.  He did his writeup before the DIY wheel was available.   http://forums.hybridz.org/topic/23244-megasquirtnspark-mssmsns-installation-guide/

 

You have spark so Megasquirt is seeing a crank signal and using it.  I wouldn't make it more complicated than it is.  Seems more like you have a software problem, Megasquirt is not doing what it's supposed to do.  Megasquirt uses "prediction algorithms" to move the timing.  Don't know how knowledgeable these guys are though. It's surprising how little information is out there about this.  Some programs use a retard method, where you set the base trigger way advanced, like 60 degrees, others use the next cycle.  Here's an interesting thread about it. 

 

http://74.124.198.224/~micro/viewtopic.php?t=17518

 

Here's a Hybriz response but moby doesn't really seem interested - http://forums.hybridz.org/topic/44373-predictor-algorithms/

 

Of course, it's not uncommon to go off on a tangent and find a problem solved without really understanding how it happened.  

 

 

Here's another thread showing how confusing it can get, and probably why nobody publishes anything about how the various algortihms work.  Best to leave a mystery.  Still might give you a new direction.

 

http://www.msextra.com/forums/viewtopic.php?f=131&t=39578&start=0

 

 

Here's another comment (picture included, but you have six slots, not four) about using the basic evenly spaced trigger wheel, which is what you have and which seems to be working.  Using a different trigger wheel should leave you with the same problem, if it's the only thing you change.  In principle  https://www.diyautotune.com/support/tech/other/megasquirt-ignition-control/

 

 

Anyway, the suggestions to try something else don't seem to be using the fact that your trigger wheel is triggering and the engine is running.  The suggestions don't follow the facts.

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post-8864-0-71963000-1458320852_thumb.png

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Just had a thought about your jumpy timing at idle.  Are you triggering on the proper edge of the holes?  Maybe Megasquirt can handle the wrong edge at idle but can't use the advance curve properly.  Depends on who write the code, someone might have added a feature to protect the engine if parameters aren't coming in correctly.  A first-derivative algorithm might fail if the points don't fit the curve.

 

Another odd possibility is that the knock sensor protection is kicking in and stopping advance.  Still spitballing.

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What I have done is ordered an extra distributor cap. You drill a hole on top of the cap at #1 Terminal so you can shine the timing light through and see where the rotor is firing in relation to the terminal.

 

You should then be able to adjust the distributor body and adjust the trigger angle to keep the spark aligned with the tip at minimum advance and maximum advance. I don't think you can change the position of the actual rotor on the Z31 dizzy. Our setup is not the same as what MSD shows in their video's of phasing with a two piece adjustable rotor on Chevy's and Ford's. You'll have to play with things a bit.

 

You may not even have to phase things at all, as Nissan has probably already designed the correct phasing in the Optical Dizzy. The Chevy and Ford dizzy's shown in Rotor phasing articles and video's were not originally designed to be used with an ECU controlling the timing curve. The Nissan Optical dizzy's are. I'd recommend setting the Dizzy up initially with it bolted down in the center of the slotted mount holes on the Dizzy base. Then you can adjust either way...if needed.

 

The spare Dizzy cap with the hole drilled at #1 terminal just makes it easier to check when running.

Wouldn't I be using a different spark mode? Where I wouldn't need the trigger offset to be set. Unless that is needed before I switch to toothed wheel. How would I be able to set it at both minimum advance and maximum advance at the distributor? That would have two different numbers would it not?

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Wouldn't I be using a different spark mode? Where I wouldn't need the trigger offset to be set. Unless that is needed before I switch to toothed wheel. How would I be able to set it at both minimum advance and maximum advance at the distributor? That would have two different numbers would it not?

 

Yes and it's all done by the software. Don't try and over think things. Get the correct Trigger wheel and follow the instructions  provided from MegaSquirt for that wheel. You ALWAYS need to set the trigger offset. That is a fundamental method of how Electronic ignition timing tables work.

 

You don't really have to know how  " Predictive Algorithms " and all the engineering details work. That is just going to hurt your brain and make you more confused. ( The following book explains things in Layman's terms that the common person can readily understand ).

 

I would really recommend getting a book called: " Performance Fuel Injection Systems " By Matt Cramer & Jerry Hoffman. ISBN 978-1-55788-557-9  Both Matt and Jerry are key members of the MS design team. This is a MUST HAVE book for MS owners.

 

Here is the simple version to understanding how ECU's control ignition timing and what Crank and Cam triggers do.

1: You have to understand that Mechanical Dizzy's ( with weights, cams and springs and vacuum pots ) physically moves the Distributor Plate ( Points, Optical or Magnetic pickup ) in relation to the TDC point.  So you can advance the ignition timing by physically moving the sensor point. This adds mechanical or vacuum advance. The Cam lobe or Reluctor wheel tells how many cylinders the engine has. This equates to the Trigger ( Crank signal ) on an ECU controlled system

 

2: With an ECU controlling the Ignition timing table the Crank signal ( Trigger ) and Cam signal ( Home ) things are totally different The sensors are in a  fixed position and do not  do not move. So how the heck can we  adjust the timing back and forth in Real time electronically? Simple:  By using a " Home " signal that tells the ECU that #! cylinder is approaching  TDC.

 

This " Home " signal is usually positioned at least 60 - 70  degrees before TDC. Why? Because total ignition timing is an additive of Static timing + Mechanical advance + Load ( vacuum advance ). This figure can easily total 45 to 50 degrees under cruise conditions. IE 15 static + 20 Mechanical + 15 vacuum/load advance = 50 degrees. The ECU needs some time to perform these calculations ( At 7,000 rpm it's all in micoseconds ) so we add a " Buffer " of   10 to 20 degree for it to have time to make it's calculations.

 

Scenario A: So the ECU now gets a signal that #1 piston is now at 70 degrees BTDC. It looks at the Timing table  and sees that at this particular RPM ( 800 rpm )  and particular Load  we want an ignition timing of 10 BTDC. So it calculates all the numbers in microseconds and sends a signal that fires the coil 60 crankshaft degrees later ( 70 degrees BTDC - 60 degrees  = 10 BTDC ) .

 

Scenario B: Now lets see what happens at 7,000 RPM at WOT. ECU now gets a signal that #1 piston is now at 70 degrees BTDC . It looks up the Timing table and sees at 7,000 RPM and a HIGH Engine load ( 0"  vacuum ) we want an ignition timing of 35 BTDC. So it calculates and sends a signal that fires the coil 35 crankshaft degrees later.  ( 70 degrees BTDC - 35 degrees  = 35 BDTC )

 

So by knowing the engine RPM and number of cylinders from the Crank ( Trigger ) signal  and the position of the #1 piston by the Cam ( Home ) signal we can now have full control over BOTH the ignition timing table and fuel timing table. You can run Sequential Fuel injection and  Coil on Plug tuning just by knowing the 3 variables. RPM, Number of Cylimders and #1 piston position.

 

In the simplest setup ( Basic or Distributor setup ) , you can have multi point Fuel injection with just a Crank sensor giving RPM and number of cylinders. That will give you Multi point or Batch Fire Fuel control ( but not sequential ) and you could run it with a standard weights and springs style distributor. The light should be going on right now... because that is essentially how you are running your setup right now.... but you do NOT have a regular weights and spring style distributor. You have a LOCKED distributor with no mechanical advance or vacuum advance ( Essentially you have a fixed Crank sensor and Cam sensor ) and that is why your Ignition timing is locked.

 

Once you get the correct Trigger wheel, and apply the correct Trigger settings, your MS2 ECU will be able to apply the proper algorithms for the new 24-1 Trigger wheel and make full use of the Timing Tables.

Edited by Chickenman

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Just had a thought about your jumpy timing at idle.  Are you triggering on the proper edge of the holes?  Maybe Megasquirt can handle the wrong edge at idle but can't use the advance curve properly.  Depends on who write the code, someone might have added a feature to protect the engine if parameters aren't coming in correctly.  A first-derivative algorithm might fail if the points don't fit the curve.

 

Another odd possibility is that the knock sensor protection is kicking in and stopping advance.  Still spitballing.

The jumping is likely because the MS2 processor cannot  properly decode the Nissan trigger wheel. The Nissan trigger wheel has 360 slits on the Crank Trigger Ring. 360 timing slits is a LOT of reference points. That takes a very fast processor to handle the calculations at higher RPM's.

 

The MS1/MS2 hardware and  it's firmware are not designed to work with the Standard Nissan wheel.  ( The MS 3 can handle the stock Nissan V31 trigger wheel, as it does have a faster processor and the necessary firmware to decode and calculate the Nissan Trigger wheel properly ). It's all documented in the MS Tech forums when you dig deep enough.

 

The MS2 can likely " stumble " by on basic settings ( at lower RPM's )  acting as Basic Distributor setup. But it can not work properly in full ignition Table mode.  It's just not possible. That is why the OP has to change Trigger wheels to one compatible with his MS2.

 

Edit: There are other things that can make the Timing jump as well, most dealing with EMI. But that is not the main issue right now. First the OP has to get the proper Trigger wheel that is compatible with his ECU and setup the proper parameters in the Software.

Edited by Chickenman

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Just to cover EMI:

 

1: Always use resistor plugs.

 

2: Always use Top Quality spiral core wire ( MSD, Magnacore, NGK are all good. Taylor & Nology are not recommended ) . Never EVER use Solid core ( or even ) Carbon core wires with any stand alone ECU. It's good quality spiral core wires or nothing... unless you like hunting down mysterious Trigger errors and such. 

 

3: Always keep the Ignition trigger wires routed well away from any HT leads but also the 12 volt power leads. The Ignition Trigger wires are very susceptible to EMI and should always be shielded wire or " Twisted Pair " wire.

 

4: If you are using an MSD or Crane style Ignition box, it must be mounted at least 3 Feet from the ECU. Aftermarket CDI or high power Inductive boxes produce massive EMI and must be well separated from the engine management ECU . Have a look at the factory ECU system on 280Z's. There is a reason why the Engine ECU is on the driver kick panel and the Trignition box is on the passenger kick panel. EMI isolation.

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^ What are referring to ZH with your attachment?  What are you trying to say?

 

In my Post #24 I included a link to a MS article that fully covers the Nissan Optical Trigger wheel issues when running the MS2 .  They developed that wheel to address specific issues without having to resort to " Band-Aid " fixes. I also Copied and Pasted the settings necessary for the MS2 and that particular Trigger wheel, just to make it easier for OP.

Edited by Chickenman

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Well right now, I have my dizzy wired up only to the crank signal and the ground. Edit: and the power which is pulled up with a resistor. Would I need to hook into the cam wire somehow? Because I don't have a "home" pin anywhere. Again. I bought the megasquirt prebuilt. I'm not sure where I would hook the cam wire into my megasquirt. Unless it involves me rewiring a few things on the mainboard..

Edited by baggedgoods

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