Making MS1 pcb 3.0 work with 4age stock distributor/ignition

FoundSoul · Post by **FoundSoul** » Wed Mar 29, 2006 7:19 am

superchargingmachine wrote:The guy I know worked the kinks out of the system you are trying to set up is James Laughlin jdlaugh@cox.net

Put a post out for JamesL and see if he is still watching MSEFI. If not try emailing him. If my memory serves me he spent a ton of time working out the system you are trying to set up. You might also search for posts by him.

James did pioneer the control of the stock VAST system, using the ignitor and all stock components and a v2.2 MS_I with MSnS-E. He did a heck of a job and is the reason so many people are running this setup today.

The problem here is.... te51levin has a toasted ignitor, a PCBv3 ECU, and is no longer using the stock ignition system of the car due to the toasted ignitor. I'm sure James could help figure it out as well as anyone-- but it's not anything like his setup at this point. Let me see what I can dig up though....

FoundSoul · Post by **FoundSoul** » Wed Mar 29, 2006 7:38 am

te51levin wrote:OK, now I really need some help. I really messed up. I wanted my thermo sensors to be accurate, so I used EasyTherm to set them up (turns out they are apparently the same as Bosch sensors, which makes sense since it's really licensed L-Jetronic anyway). What I failed to notice is that after doing that, EVERYTHING went back to base maps. The car ran horribly, so I started setting it back up the way it was. Unfortunately I didn't remember about the dwell settings, so I roached the igniter. Not cool!

Now, I think I have the board set up to work the coil directly. I have the VR921 installed at Q16 and the whole VR circuit is in place. Jumpers are as follows:

IGN to IGBTOUT; IGN is pin 36 going to coil (-)
TSEL to VROUT
TACHSELECT to VRIN
IGBTIN to 330-ohm resitor to top of R26

I also have the following left over from the VAST setup:
D1 (jumper, not diode) to 1K resistor to D9 (non-banded end)
D2 is still a jumper, not a diode

I have yet to run this. I think it'll run the coil OK, but I want to be able to run the tach as well. What exactly powers the tach? And can someone with experience/wisdom/courage comment on my progress so far so I don't fry something else, like a tach or the MS or...?

Can I mix and match jumpers to get a signal that the tach likes while still using the VR921 and VR circuit to drive the coil?

Should I install a diode on D2?

I too have fried my ignitor after updating my firmware and not checking the dwell settings once (defaulted to 75%=cooked ignitor)... I hit up the guys on MR2OC.com and found another one cheap. You could do the same or....

With the fried ignitor and still using the hall/opto input-- when you turned the engine over were you still getting a TACH signal? If so the ignitor is still doing part of it's job and shaping the VR sensors output into a square wave. You could then leave it in place conditioning the VR sensor signal into a square wave and continue to use the Hall/Opto input-- that's up to you. Or you could probably ditch the ignitor altogether and use the VR input on the MS to condition the signal for you if you wanted to, which looking at the jumpers you've set looks like the path you've chosen, and should work fine.

You VR input jumpers look fine. You don't need to mess with D2 as you're not even using the hall/opto input anymore.

You're output to directly fire the coil looks fine too, assuming the (+) terminal of the coil is getting 12v+ power in the CRANK and RUN positions.

You need to make sure SPARK OUTPUT INVERTED is set to YES. You need to use Dwell Control. This two settings will prevent VB921 and/or coil damage.

As for triggering your tach-- the negative terminal of the coil will usually work though you might trace it back in the factory schematics and see where they triggered it from.

te51levin · Post by **te51levin** » Wed Mar 29, 2006 7:41 am

Speaking of james, this indicates that the tach does indeed run off of a square wave:
http://members.cox.net/jdlaugh/index_fi ... nector.jpg

I'll be studying the assembly manual and other things more tonight to see whether anything must be, or can be, done to make this situation workable.

Jamesl · Post by **Jamesl** » Wed Mar 29, 2006 6:55 pm

Speaking of James.... I haven't been visiting the board much lately. The Mr2 had been running great until recently, when I fried U7, the injector driver. Not sure what happened, but I did have some bad/loose solder joints in my harness connector, which may have contributed to the problem.

I've pretty much lost track of the MS world. It moves so fast, I've been left behind. Heck, I'm still using Megatune 2.25 beta from back in Nov. 2004. Who knows what changes have been made since then!!!!

Maybe I should read up on the changing world of MS and see what's new and interesting..

Oh, and I'm not sure what kind of signal is used by the tachometer. In my connector jpg, referenced above, I was referring to the square wave signal that goes from the ignitor to MS -- "Tach" in this case is just a generic term. Toyota refers to it as the NE signal.

Looking at the diagrams for my '87 Mr2, the "IGF" signal goes to both the ECU and to the Tachometer. According to the www.autoshop101.com site, the IGF is merely a confirmation signal that a spark event has occurred. It doesn't describe what type of signal is used.

superchargingmachine · Thu Mar 30, 2006 7:14 am

I'm using wasted spark and the circuit below.

Based on this I think(THIS IS NOT TESTED)that you can hook the tach to the negative coil lead on single coil system. I'm not an electronics guru tho so I think I would put the 15-18V Zener between the coil and tach. If someone wants to take a chance and test this post the results.

te51levin · Post by **te51levin** » Thu Mar 30, 2006 12:46 pm

Thanks - I think I'll be trying that diode if the tach doesn't work right off the -VE terminal of the coil.

I have eliminated the ignitor and almost been able to start the car. I ran the VR sensor directly to the MS via the DB37 connector, and ran coil trigger from DB37 through the ECU connector (I'm writing from work and don't remember exactly which pin I used), using a wire that had continuity to a terminal on the big ignitor connector, and from that wire to the -VE coil terminal. The coil +VE power wire is intact, as it bypasses the igniter in stock configuration. Dwell is set to 3.0 for both cranking and running and spark output inverted is set to YES. I have not yet tried to connect the tach.

Result: it showed RPM during cranking, and sort of tried to fire, but also tried to keep the starter engaged when it caught. I wonder if that is a totally seperate problem (low batery voltage, for example). Regardless, the next step is to run a dedicated coil trigger wire directly from the DB37 to the coil, bypassing the stock harness entirely. superchargingmachine has also come through with an igniter on the way, in case I just can't get the thing to work.

Fingers are crossed that this will be an improvement (by way of eliminating a failure-prone component) and not just a massive waste of time and effort!

te51levin · Post by **te51levin** » Fri Mar 31, 2006 7:44 am

This is frustrating. It's not sparking. I ran a dedicated wire from pin 36 to the -VE coil terminal. The +VE terminal is getting 12V with the switch at START and RUN. AFAIK there aren't any other wires that must be run to the coil (except the tach signal which I'm not worried about right now). More diagnosis will be performed on the board itself, but everything worked great on the stimulator.

FoundSoul · Post by **FoundSoul** » Fri Mar 31, 2006 8:00 am

And you have LED17 configured as the spark output in MegaTune?

I often use a PC's soundcard with a oscilloscope probe and the Windows Oscilloscope software to test ignition signals, it's super cheap and works great. Here's the software: http://polly.phys.msu.ru/~zeld/oscill.html

You can solder a wire to pin 36 on the bottom of the stimulator and scope this wire to test the ignition output on stim.

te51levin · Post by **te51levin** » Fri Mar 31, 2006 10:53 am

Thanks, that's a good idea. I bet I can do the same thing with Audacity (link: http://audacity.sourceforge.net/ ), a free audio editing program I already have. In fact it sounds like that's exactly what I've been doing to get a signal to Streetdyno (recording ignition events from the -VE side of the coil via the diagnostic connector). I can use it to view impulses in a visible wave format much like an oscilloscope. I'll see if it produces anything on the stim. If that comes up OK, I'll look at the VR pickup in the distributor and make sure it's doing its job (got a spare for that at home too). I really hope it can be made to work without the ignitor...

te51levin · Post by **te51levin** » Sat Apr 01, 2006 11:05 am

I tried Windows Oscilloscope running on the stim and got some very sharp waves off pin 36 (coil trigger). Running it into Audacity, which I'm more familiar with, produced a faint wavy line. While going over the msns-extra page I also found this:

I hadn't even populated the PWM flyback damping circuit that Q9 uses, so I went ahead and added it. After populating that circuit, Audacity shows a very nearly square wave at pin 36.

I am confused by that drawing, though. Is that for a v2.2 board or v3? If that's something I need to add, I need help identifying exactly what I'm doing. I can find all the numbered components (Q9, D17, R23, etc). Specifically, I am not sure about X11 and VCC.

Is the drawing above even relevant, since I am using the circuit below to control the coil?

At any rate, I have washed the board just in case flux was an issue, and am baking it at 180 for ten minutes to dry it out before I try it again.

te51levin · Post by **te51levin** » Sat Apr 01, 2006 11:57 am

I don't know if this is useful or not, but here is a screen capture of the signal at pin 36. This represents 600, 3000, 6000, and 9000 rpm on the stim. As soon as I am done with some domestic chores I'm going to plug it in again and see what happens.

te51levin · Post by **te51levin** » Sat Apr 01, 2006 6:23 pm

Well, it's better, but still not running. I do get sparks at the correct times, but they are weak and orange. Trying a different coil had no effect. I believe the VR pickup is still good (as evidenced by the sparks occuring when they should). I've tried messing with the cranking dwell as high as 6 ms but I'm not eager to go any higher and fry a coil as well.

Here are my jumpers and additional circuit. The red wire goes from the top of R26, to a 1K resistor on the proto board, to IGBTIN.

For sale, one 1985 MR2, no rust, great 7AGE engine, needs igniter and patient owner/mechanic. Will consider partial trade for running flathead Ford and substantial quantities of adult beverages.

EDIT: Just found this - looks like I missed it during setup (musta thought it didn't apply to my system): http://megasquirt.sourceforge.net/extra ... wheel.html Apparently TSEL should have a jumper to VROUTINV, not VROUT. Comments? I'll try it in the morning and hopefully have fat blue sparks to get all excited about.

FoundSoul · Post by **FoundSoul** » Sun Apr 02, 2006 11:09 am

te51levin wrote:I tried Windows Oscilloscope running on the stim and got some very sharp waves off pin 36 (coil trigger). Running it into Audacity, which I'm more familiar with, produced a faint wavy line. While going over the msns-extra page I also found this:

I hadn't even populated the PWM flyback damping circuit that Q9 uses, so I went ahead and added it. After populating that circuit, Audacity shows a very nearly square wave at pin 36.

I am confused by that drawing, though. Is that for a v2.2 board or v3? If that's something I need to add, I need help identifying exactly what I'm doing. I can find all the numbered components (Q9, D17, R23, etc). Specifically, I am not sure about X11 and VCC.

That drawing above is from the PCB2.2 schematic so you can't base anything off of the reference #'s there. The same circuit is on the V3, just with different reference #'s.

te51levin wrote: Is the drawing above even relevant, since I am using the circuit below to control the coil?

At any rate, I have washed the board just in case flux was an issue, and am baking it at 180 for ten minutes to dry it out before I try it again.

And no-- that top drawing isn't really relevant to you here since you're driving the coil directly as per the second drawing-- that's the right way to do things here...

FoundSoul · Post by **FoundSoul** » Sun Apr 02, 2006 11:15 am

te51levin wrote:Well, it's better, but still not running. I do get sparks at the correct times, but they are weak and orange. Trying a different coil had no effect. I believe the VR pickup is still good (as evidenced by the sparks occuring when they should). I've tried messing with the cranking dwell as high as 6 ms but I'm not eager to go any higher and fry a coil as well.

Here are my jumpers and additional circuit. The red wire goes from the top of R26, to a 1K resistor on the proto board, to IGBTIN.

Why a 1k resistor and not a 330 ohm as per the schematic above? I haven't tried this with a 1k but I've had got luck with the 330ohm and would recommend trying that.

te51levin wrote:

For sale, one 1985 MR2, no rust, great 7AGE engine, needs igniter and patient owner/mechanic. Will consider partial trade for running flathead Ford and substantial quantities of adult beverages.

EDIT: Just found this - looks like I missed it during setup (musta thought it didn't apply to my system): http://megasquirt.sourceforge.net/extra ... wheel.html Apparently TSEL should have a jumper to VROUTINV, not VROUT. Comments? I'll try it in the morning and hopefully have fat blue sparks to get all excited about.

I'm not 100% sure on the VROUT vs VROUTINV jumper in your situation, I'd start with the 330ohm resistor instead of the 1k though, and then you can easily change that jumper if needed.

Keep us posted man... You're too close to trade it for a Ford and beer now ;)

te51levin · Post by **te51levin** » Sun Apr 02, 2006 1:41 pm

FoundSoul wrote:I'm not 100% sure on the VROUT vs VROUTINV jumper in your situation, I'd start with the 330ohm resistor instead of the 1k though, and then you can easily change that jumper if needed.

Keep us posted man... You're too close to trade it for a Ford and beer now ;)

That was a misprint on my part. The resistor is indeed 330 ohm as called for.

Jumpering to VROUTINV did not improve the situation. This is really starting to bother me. Somebody somewhere has an answer, but I haven't found it yet.

FoundSoul · Post by **FoundSoul** » Mon Apr 03, 2006 6:02 am

So you're getting weak sparks during cranking.... weak battery maybe?

Have you actually tried to fire it up? There's no reason I can think of that the spark should be weak if the primary winding of the coil is getting ample voltage/current. If it's triggering at the correct timing as you suspect and the VB921 is firing the coil properly as it seems to be then maybe the battery is just a bit low and it will fire great once it pops off?

te51levin · Post by **te51levin** » Mon Apr 03, 2006 6:58 am

The battery is strong enough - in fact I've been boosting it with jumper cables to the wife's Camry. I'll double-check power to the coil and any relevant fuses and relays.

FoundSoul · Post by **FoundSoul** » Mon Apr 03, 2006 7:14 am

Aside from how the spark looks... does the car start? I did a little searching around for VB921 dwell settings and it looks like 3ms running dwell is recommended, though 5-6 should be fine at cranking. The VB921 should be maybe a bit warm when running but not hot. The coil should be warm, but easily cool enough to lay your hand on...

te51levin · Post by **te51levin** » Mon Apr 03, 2006 8:32 am

Nope, it's not even starting. Every so often it will make a weak effort and sputter, but will absolutely not start.

I don't remember reading anywhere that the MS case must be grounded to chassis. I'm ass-u-ming that's not a factor...?

FoundSoul · Post by **FoundSoul** » Mon Apr 03, 2006 9:10 am

MS Case doesn't need to be grounded. I'm starting to run short on ideas for you here without being able to put my hands on it. I'd suggest a thread dedicated to your 'weak spark using VB921 and stock coil' issue in the MSnS-E forums here, detailing your setup and let's see if anyone new chimes in with a good idea that I'm missing here. You're not going to get alot of guys looking in this thread as this is really off topic for this thread beings this is the 'how to use your stock ignition system' thread for the 4AG. So the people that aren't interested in that won't jump in and see that you're now using this thread to troubleshoot your issue, you'll need a new thread to draw some attention.