Matt Cramer

The MSnS-E setup for a seven or eight pin HEI module is a little different. You'll have it controlling both the E and B pins: http://www.msextra.com/manuals/MS_Extra_Ignition_Hardware_Manual.htm#gm7hei I have an HEI ignition working with a Mopar Lean Burn distributor on my Dodge Dart. Just have a seven pin module bolted to my inner fenderwell. The HEI system works with a lot of different VR sensor based distributors.

The later Stims with the IGN LED light provide some measure of testing a VB921. However, trying to track down intermittant operation in one is a real nightmare. I can't think of any trick that does not involve an oscillascope at the very least.

The resistor was there to protect the circuits on the older ones - if you have a new LC-1 (the one with the "dark thunderstorm" box), you won't need it.

I wouldn't recommend trying to build an ECU that works like that. Most PC operating systems are not designed to run devices that need real-time control - Windows certainly isn't. The trouble with running a laptop based ECU is making sure your operating system won't try to distribute processing time in a way that might, for example, cause your ignition pulses to be delayed by a couple hundred miliseconds since it absolutely HAS to get your copy of Winamp open quickly.

The way that is set up, you will see 12 volts on the G pin when Megasquirt is not sending a signal, and Megasquirt needs to actively turn on a transistor to bring the voltage down to zero. The first thing to look at is whether you're getting any RPM while cranking. If you do not see any RPM, the problem is on the input side - there is no signal from the distributor, or it isn't reaching the Megasquirt CPU. If you do get an RPM reading, but no spark, the issue is with the output side. To see if the problem is inside or outside Megasquirt, try plugging it into a Stimulator. On the Stim, you should get an RPM reading if the input is working, and have the FIDLE LED blink if the output is working.

Only the earliest Megasquirts came with the MPX4115 standard, back in the days of group buys. It's possible, but unlikely, that some distributor out there is selling Megasquirts with this sensor. I don't know where you got that Megasquirt, and some of the installs out there do use GM MAP sensors, but all of our V2.2 and V3.0 Megasquirts use the MPX4250 sensors except for ones special ordered with 4 bar sensors. The 2.5 bar sensor works pretty well on both NA and turbo motors - and we have had some people use the 4 bar on NA motors without any trouble. If your Megasquirt does in fact have a 2.5 bar MAP sensor and telling it you had a 2 bar got it running better, I suspect it was running too lean.

For that matter, you can replace two four-pin HEI modules with a single seven pin unit. My Dodge Dart has a Mopar VR distributor hooked up to a GM HEI seven pin module (I'm using a V2.2 board, so I don't have a VR conditioner).

The thing is that diesel engines running multi-stage turbos typically use them to make boost levels that would be completely insane on gasoline - some of these run well in excess of 100 psi. It seems like a single turbo would be more efficient until you get to around 40 psi of boost. Multi-stage turbo systems are mostly for reaching insane pressure levels rather than decreasing spool-up time.

Yes, just run the jumper like in the photo.

260zturbo, That black box is a relay - basically, a mechanical switch driven by electrical power. It can't act fast enough to control your ignition. With an MSD, you will just run that black wire you see in the photo - no resistor should be necessary.

All right, take a look at your relay board. There should be three sockets in there. Is there a relay in each socket? Or is the relay nearest the connector from the Megaquirt gone, and a length of wire in its place? If there's a relay in there, that would mean you're trying to use the relay to drive the spark output, and relays don't work very well for that.

Also, since you're using a relay board - did you pull the fast idle relay and run a jumper instead?

Looks like I don't have much to add here, but there is one thing I'd like to comment on. For installing an injected engine in a car that previously had a carburetor, a relay board will make things a lot easier. I've done a carb to EFI swap without it, and found it would have been easier to get a board with all the relays and fuses on it. If you decide you want to go with the relay board, instead of the harness, you will want to go with a relay cable to connect the Megasquirt to the relay board, and a wire bundle to connect the relay board to the engine.

You do need a couple of jumpers for ignition control, but nothing major with a V3.0 board. On a Ford 5.0, either one of these will need mods for fast idle control, as the Ford uses a pulse width modulated idle. The only real advantage the MS-II will have in this particular situation is that it has the higher processor speed and more precise injector control.

24OZ, Some downloads of MegaTune do not have the latest INI files. The 029C will be the wrong one for yours if it was a recent order. You'll need the 029q INI file, available from the MSnS-E manual: http://www.msextra.com/manuals/MS_Extra_Manual_Index.htm The download link is at the bottom of the page.

If you're using a Megasquirt in fuel only mode, you can simplify the tach output a bit. I don't think a H-6 lets you trigger off the negative terminal of the coil, but it probably has a tach output wire that will serve as a perfectly good tach input for Megasquirt. Usually that will work with a standard trigger-off-the-coil or Hall/Opto circuit with no pull-up resistor or anything.

It sounds like you have MegaTune configured for the standard Megasquirt code instead of MSnS-E. You'll need to change which code version you are using in the Megatune Configurator.

From that picture, it looks like you already have the jumpers needed for using the VB921 coil driver with MSnS-E already set up. Although that sensor is an optical rather than Hall effect, the wiring is the same. The biggest difference is that the description on our site shows an external pull-up resistor, while the drawings Trwebb posted show an internal pull-up. They look a little different, but function the same way.

The input mods will be already done. Our off the shelf unit will not have the jumpers for the direct coil control output mod, although we have built some special order units set up that way. If you did not special order it with the mod in place, here's how to add it: http://www.msextra.com/manuals/MS_Extra_Ignition_Hardware_Manual.htm#singlecoil

I'd say yes to all of the above. I'm running an LC-1 with no gauge (well, actually, there's a cheapo ten-bar gauge in there that burned out) and I watch my AFR readings with MegaTune while tuning. The LC-1 works with a couple different gauges - the XD-16 works with a couple other Innovate products, but you can use a variety of digital or analog gauges with it depending on the look you want.

If the ECU is getting an RPM, that should mean it's seeing the PIP signal perfectly. That also suggests that your input circuit is wired correctly. So it's time to test the output circuit and the configuration. You can find the definitive EDIS wiring guide here: http://www.msextra.com/manuals/MS_Extra_Ignition_Hardware_Manual.htm#edis Make sure you are using the V2.2 output wiring and sending the spark out the right connection on the DB37. Here are some things to check: Which one is set to Spark A in MegaTune: FIdle or LED17? Which pin on the DB37 connector goes to pin 3 on the EDIS module? What is connected to jumpers X11, X12, X13, and X14? (You probably won't have all these connected).

While there's a Hall sensor in the Pertronix, you won't actually get to access it unless you cut the casing open. It's better to set this up to behave like you are using points; see this link for the details: http://www.msextra.com/manuals/MS_Extra_Ignition_Hardware_Manual.htm#points

This sounds like one of two things. One, check your configuration. Under Spark Settings, do you have Fixed Angle set to -10? If it's set anywhere else, Megasquirt will hold the timing steady. The other possibility is that the SAW output isn't reaching the EDIS module, or is faulty.

Are you running a PWM idle valve? Some of the things this could be are rather bad. If it does this at idle, I would check the voltage on the fuel pump output to be sure it's not turning the fuel pump on and off. It wouldn't be so worrisome if this is the fast idle valve it's turning on and off.

If you have no pulsewidth showing in Megatune, but it is showing RPM, it sounds like you've got something strange in your configuration. Is it showing that it's in flood clear mode? If not, could you post your MSQ file here? I could take a look at it if you'd like.