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baggedgoods

Megasquirt ignition and timing problems

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The car runs and drives okay. Still haven't gone through much of the fuel tables.

 

Can't seem to get the timing to adjust electronically through the megasquirt. I can set the timing mechanically but I can't get it to advance or regard through the megasquirt. I've adjusted the trigger angle and that doesn't seem to sway it either way.

 

I have an 85 300zx turbo with a completely stock ignition system. MS2/Extra firmware: 3.3.0

 

I've read all over about controlling spark with distributors and an ignition coil /power transistor, but I can't seem to get it to do what I want.

 

Any advice would be amazing.

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I have an 85 300zx turbo with a completely stock ignition system. MS2/Extra firmware: 3.3.0

 

I've read all over about controlling spark with distributors and an ignition coil /power transistor, but I can't seem to get it to do what I want.

Add more detail.  Like what's connected to the power transistor,  MS settings, etc.  Stuff that describes what you have, beyond "stock ignition system".  I can say that there's not much to work with in your post, and I don't even have Megasquirt.

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Sorry, first time posting onto a forum.

 

I have my spark A output wire connected to the 12V of my power transistor which I have pulled down to 5V through a 1k ohm resistor. My CAS is wired correctly because my car starts and runs and I have an rpm signal. So I don't generally think that's the problem.

 

To my understanding, the spark a wire should be wired into the ground of the coil. I have tried running it to the ground of the coil and the ground of the power transistor. But that doesn't seem to work. Wiring it to the power allows it to work but I'm unable to adjust any timing with megasquirt. I could post my settings in megasquirt. I'm not at my computer atm.

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I've read through it a couple times. The problem I'm having is when I try adjusting the timing through Megasquirt, the timing doesn't move on the crank. I set my fixed advance to 15 degrees, then spun the distributor until the timing light read 15 degrees at the crank pulley. When I change it back to "use table", Megasquirt will show my timing is at whatever my cells are set to, but on the crank pulley, it stays at 15. I've played with the throttle while checking the timing to see if it will move according to map pressure. But it stays fixed to around 15 and kind of bounces between 14-16 degrees.

 

I can't post my msq file for some reason, but I can post some screenshots of my ignition settings and spark table. I'd prefer to use the spark table to tune ignition, but if theres another way, I'm all ears haha.

post-52146-0-45241500-1457837645_thumb.png

post-52146-0-69082800-1457837652_thumb.png

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Follow-up: Megasquirt is seeing your crank signal,and controlling the coil.  The engine runs, but it's just not advancing timing.  You're driving around with no timing advance at all.  

Yes, Megasquirt is seeing my crank signal because I am using it for my tach, and my tach is working properly. When i rev the engine with a timing light on it, the timing does not move. It's possible this could be an issue with the distributor, but it doesn't make much sense to me.

 

Setting your base timing in Tuner Studio. How did you come up with your trigger offset of 60 degrees?

Well I've researched a lot about my distributor wheel and they say for Nissans on the DIY site that they have 360 teeth with 6 slots for each cylinder, and each slot is 60 degrees apart. https://www.diyautotune.com/support/tech/other/megasquirt-ignition-control/

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The 1k ohm resistor should be wired into #24 megasquirt wire and a 12 volt source. Have you gone over your install wiring ??..

 

Once you get the timing control figured out. Just looking and the spark table doesn't show Map on the left column, its ignition based. Just looks odd to me. Is that the only way the spark table is set up with the extra code ??.. If so your timing is waay to high on the upper half of that spark table.

Edited by dexter72

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Yes, Megasquirt is seeing my crank signal because I am using it for my tach, and my tach is working properly. When i rev the engine with a timing light on it, the timing does not move. It's possible this could be an issue with the distributor, but it doesn't make much sense to me.

 

Well I've researched a lot about my distributor wheel and they say for Nissans on the DIY site that they have 360 teeth with 6 slots for each cylinder, and each slot is 60 degrees apart. https://www.diyautotune.com/support/tech/other/megasquirt-ignition-control/

Another wild guess, or a clue for someone else - in Tunerstudio do you see the tach signal?  Does it read the RPM?  You said "tach" but I assume that means your in-car dash tach.  I think that MS can use different sources for the tach signal.  The software isn't perfected so it's highly likely that it's possible to set conflicting variables, that give results that don't make sense.
 
Copied a paragraph from the manual as example.  Maybe there's a way to set crank angle control, but still using coil output as trigger?  Edit - and you're missing the crank angle signal.
 
Only here for the puzzle.  Anyone who knows the answer, feel free to crush my views.

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Edited by NewZed

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The 1k ohm resistor should be wired into #24 megasquirt wire and a 12 volt source. Have you gone over your install wiring ??..

 

Once you get the timing control figured out. Just looking and the spark table doesn't show Map on the left column, its ignition based. Just looks odd to me. Is that the only way the spark table is set up with the extra code ??.. If so your timing is waay to high on the upper half of that spark table.

Yeah, I already have pin 24 pulled up to 12V with a 1k ohm resistor. Then for pin 36 I have it pulled down to 5V through a 1k resistor.

 

I haven't even messed with my higher end timing because I can't even adjust my timing through TunerStudio.

 

My bad, I meant I could read the RPMs not tach in TunerStudio through my cas signal. I'm not sure how to change the source that TunerStudio reads the rpms from. I will look up some stuff about it later. I will post pictures of my setup in more detail later. Thanks guys. I've had such a headache with this thing.

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Yes, Megasquirt is seeing my crank signal because I am using it for my tach, and my tach is working properly. When i rev the engine with a timing light on it, the timing does not move. It's possible this could be an issue with the distributor, but it doesn't make much sense to me.

 

Seems like there's a setting somewhere that isn't right.  The ECU and software adjust timing by changing the coil grounding moment in relation to the base timing.  So, the program just isn't controlling the coil ground like it should.  The distributor is distributing and the CAS inside it must be communicating with the ECU to generate the base timing signal to create a spark.  The engine runs.

 

Could be that there's an input variable that is so far out of range that the software defaults to no advance.  Maybe the MAP variable is set wrong.  Maybe temperature reading?  http://www.megamanual.com/ms2/ign_timing.htm

 

Just offering ideas, and picking up some knowledge myself.

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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.

Edited by baggedgoods

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Have you gone to the Megasquirt Forum and checked there? That would be the best place to start.

 

That being said I think you have a Software setting wrong. To me it looks like you have " Fixed Advance " still activated. You are supposed to lock the Timing ( Fixed Advance ) to adjust your Tooth/Ignition Offset in the program. BTW, you should not be turning the dizzy to do this. ( Read up on rotor phasing ).

 

Once you have verified with a timing light that your have your Ignition offset  correct, then you have to Apply or " Burn " the settings. That locks in your Ignition offset. ( Which, by your screen shot, is 15 BTDC. That " coincidence " is a big Red Flag that your Ignition Timing is still in " Fixed Mode ").

 

Next you have to go back into " Fixed Advance " and change it to " Use Table ". Then you have to " Burn " it again. Think of the burn button as an Apply button. After you have made changes you have to remember to " Burn " them. Otherwise as soon as you turn the ignition off, any changes you make will not be retained and it will revert back to previous settings.

 

After " Burning " the settings, turn the ignition off, wait 10 seconds and then turn back on. New setting should be applied. ( Not sure if MS requires the ignition to be turned off then on again,  but it doesn't hurt. MS Forums can answer that ).

 

Read the following link and make sure you understand it.

 

https://www.diyautotune.com/support/tech/other/base-timing/

Edited by Chickenman

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