Megasquirt ignition and timing problems

[Matt Cramer]

 

 

Ok, I'm a bit confused by the above statement.  If the Factory trigger disc is supported by MS2, then why did DIY bring out the new designed trigger disc and mention on their sites that the MS2 combined with the factory Nissan disc has synch issues? If there are no issues then this is a bit misleading to customers. Something missing here...

 

Can you send me a link to what documentation you're referring to? I checked our documentation and I do not see any point where we state there are sync issues with the stock CAS. The new trigger disc's benefits are (1) improved spark accuracy when using MS2 and (2) cylinder identification.

 

 

 

Is it only when the MS2 uses the outer ring ( 360 slits ) for the Crank signal  that this occurs. As you mentioned using the inner ring with only 6 slits has limitations with resolution. Doesn't seem right to me??? Can the MS2 properly use the outer 360 slit ring as it was intended for the Crank signal. MS and DIY seem to indicate that it has synch problems when the 360 slits are used. The fact that you mentioned that you have to use the " Basic Trigger " setup with the inner 6 lit ring on the Stock Nissan wheel ( As The Crank signal ) seems to support this. Is this correct?

 

MS1 and MS2 do not use the outer ring of 360 slits, and never supported this. Both of these only used the inner six slots, from the first "Mobythevan" install to the current code. There were a few experimental attempts to use the 360 slot ring on MS1 and MS2, but they didn't pan out - Nissan used purpose built hardware to handle the high resolution ring, but all the attempts I've seen were code-only and did not attempt to address this.

 

 

 

Which Trigger wheel has superior performance and capabilities with an MS2. The factory Nissan ring or the DIY 24 + 1 ring? If the new DIY ring has no advantages, then why was it brought out? Please clarify.

 

The DIY ring adds cylinder identification and improves spark accuracy over the factory ring.

 

 

 

What are the capabilities with the MS3?  Can it read the outer 360 slit properly with no synch errors and can it decode the stock Nissan VG31 ring properly to run full sequential Fuel and Direct Fire ignition? Please clarify..

 

MS3 can read the high res wheel but needs to be coded for the specific inner pattern. Currently we have the RWD SR20DET, VG30DE / RB, and GM Optispark patterns coded; the "One long and the others short" is not coded. The 360 slits are used during cranking and at 1000 RPM or below, and then it uses only the inner slots - we did this based on information about how many of the factory ECUs handled the 360 slits.

 

Early implementations of this code had a bug - the thread you linked to is one such example. The issue was corrected in MS3 V1.3.3 firmware and we have not seen any indication of it re-surfacing in subsequent releases.

[skirkland1980]

Ive skimmed through and haven't read every post but i had the same problem about two years ago. I had to turn off ms every time i adjusted trigger angle. There's also certain trigger angles that will not work. Like 20-40 or something like that. Setting up ignition is really the only hard part to getting the car running correctly.

[BLOZ UP]

There was a trigger angle bug, that I tried to get more information on but was rebuffed. I had an issue where my trigger angle was different all of the sudden (between starts). After updating to the firmware that had that bug fixed, it jumped back. Whether it was the cause or I was on crack has yet to be determined.

[baggedgoods]

A long awaited update. So Chickenman has helped me deduct that when I thought I was powering down my megasquirt, I wasn't actually powering it down. I was only restarting the sync with the laptop. (Completely blew my mind lol). Now I have my MS hooked up to a switched power and I have yet to start digging into it again. I haven't had much time since the last time I've been here to try any of your suggestions. I've been researching as much as I can and I'm going to get dirty with the Z again. I hope this thread isn't dead, but I have a few questions.

 

I've looked all over for wiring the dizzy to control ignition timing. I have my tach wired up and it works on Tuner Studios. I only have pin 24 hooked up to 3 out of the 4 dizzy wires. I know one wire is for a 360 degree(crank) signal and one is for a 60 degree(cam) signal. I've had the car started with the old trigger wheel but I couldn't control timing.(I believe it might have been the power cycling issue) I haven't gotten it started with the 12-1 DIY trigger wheel. Would the one signal wire read RPM and control timing, or would I need to hookup a wire for a HOME signal also? Or does the megasquirt control the timing through the ignition coil?

Edited August 30, 2016 by baggedgoods

[BLOZ UP]

You want to "lock" your distributor to a known angle, and match that setting on the megasquirt, and then adjust your timing from megasquirt only. Megasquirt can be directly connected to the coil to trigger it, and thus control the timing. As long as your dwell is sane it won't blow up. 2ms dwell is a good start.

 

For the DIY trigger wheel, you use the same wire for the cylinder TDC on the OE wheel (the 6 slot one). You just need the signal and ground, it's an optical sensor.

[baggedgoods]

You want to "lock" your distributor to a known angle, and match that setting on the megasquirt, and then adjust your timing from megasquirt only. Megasquirt can be directly connected to the coil to trigger it, and thus control the timing. As long as your dwell is sane it won't blow up. 2ms dwell is a good start.

 

For the DIY trigger wheel, you use the same wire for the cylinder TDC on the OE wheel (the 6 slot one). You just need the signal and ground, it's an optical sensor.

So I have to match the timing that I have locked my distributor to on the megasquirt. I'd do that by adjusting the trigger angle? Because my dizzy would be locked out at say "15" but megasquirt would read Something like "17.9". Adjusting the trigger angle would change the megasquirt reading and not the actual dizzy reading. Until I change my table to "use table" correct?

 

And also. The same wire that runs the tach in megasquirt pin 24 is the same wire that reads the 6 slot part? Or 12 slot in my case. Thanks!

[Chickenman]

For the DIY trigger wheel, you use the same wire for the cylinder TDC on the OE wheel (the 6 slot one). You just need the signal and ground, it's an optical sensor.

1985 300ZX Optical Dizzy has four connections. You also have to connect the +12v feed or no worky. For Batch Fire Fuel injection and a single Coil you need Crank signal, +12v and sensor ground hooked up. For vsequential Fuel Injection and/or Coil On Plug ignition you also need the Cam sensor connection.

 

Baggedgods: I sent you a PM with pictures of my 280ZX Turbo Dizzy wiring. 300ZX Dizzy wiring is the same ( Optical modules are interchangeable between L28 Turbo Dizzy and VG30E dizzy ) . Did you get it?

 

Also check Post # 50 for setup for Sequential Injection. Click on Thumbnail. PM me if you want to do some Online tuning and setup like we did before.

[Chickenman]

So I have to match the timing that I have locked my distributor to on the megasquirt. I'd do that by adjusting the trigger angle? Because my dizzy would be locked out at say "15" but megasquirt would read Something like "17.9". Adjusting the trigger angle would change the megasquirt reading and not the actual dizzy reading. Until I change my table to "use table" correct?

 

 

 

Correct... Because the Crank sensor can usually be physically adjusted ( IE: as in a 36 - 1 wheel ) there has to be some way to let the ECU know where the Crank sensor is in relation to TDC. Being that the MS is a Universal ECU  and used on hundreds of different engines.

 

Once you have the Trigger angle setup and matching, remember to " Unlock" the  Trigger Angle check box and cycle the Ignition switch. Then MS will be able to use the programmable timing table.

[BLOZ UP]

1985 300ZX Optical Dizzy has four connections. You also have to connect the +12v feed or no worky. For Batch Fire Fuel injection and a single Coil you need Crank signal, +12v and sensor ground hooked up. For vsequential Fuel Injection and/or Coil On Plug ignition you also need the Cam sensor connection.

 

Baggedgods: I sent you a PM with pictures of my 280ZX Turbo Dizzy wiring. 300ZX Dizzy wiring is the same ( Optical modules are interchangeable between L28 Turbo Dizzy and VG30E dizzy ) . Did you get it?

 

Also check Post # 50 for setup for Sequential Injection. Click on Thumbnail. PM me if you want to do some Online tuning and setup like we did before.

 

Yeah, you're right. You need power, signal and ground. Last time I checked the code (MS, MSExtra 1/2) did not support the 360 degree wheel. It's either the 6 slot wheel (cylinder) for batch, or the DIY wheel if you want sequential.

 

 

So I have to match the timing that I have locked my distributor to on the megasquirt. I'd do that by adjusting the trigger angle? Because my dizzy would be locked out at say "15" but megasquirt would read Something like "17.9". Adjusting the trigger angle would change the megasquirt reading and not the actual dizzy reading. Until I change my table to "use table" correct?

 

Yep. Sounds like you got it, but again: Lock megasquirt to 10 degrees or whatever it will idle at. Then, with a timing light, see what the actual timing is. It could be higher or lower than the timing megasquirt thinks it's using. Say it is 15 degrees, you then adjust your trigger angle (either more or less, depends on which direction you are trying to go) until the timing light matches what megasquirt is commanding (the fixed 10 degrees). Use small trigger angle steps at first to find out which way the timing light will go so you don't stall. You can move in larger steps once you know you're headed in the right direction.

 

Now, I have heard if you want to run extreme timing (For cruising MPG or whatever), you need to have the distributor set all the way unwound (or is it wound?). This allows you to run ~50 degrees maximum advance without jumping to the wrong plug. I just got the distributor more or less in the middle and worked my trigger angle from there. This was best for clearing my Maxima intake.

[rick88ss]

Good read. Lots of good info on here. 

Any updates though?? LOL

Did the OP finally get his Z running?