First off, big thanks to boost for helping me figure out my tach signal problems. I'm working with an MSD 6A and I just couldn't find some of these simple modifications on the internet anywhere. If anyone is running a MS with a MSD you'll want to terminate the tach signal by using the default method of XG1 and XG2, but in place of the D8 diode you'll want to put a 1k resistor and grab signal directly from tach out on the MSD(duh).

I got the car idling last night and took it around the block without any driveability problems. Just ran it VERY slowly because we forgot to put trans fluid back in. What an awesome feeling having the car run...

http://b18c5.org/mustang/ecu/
http://b18c5.org/mustang/journal.txt

 

Congrats!!

I liked your log book there.

Are you using the TFI for signal still? What is your set-up with the MS? I know there are a lot of different ways to use it. Also, what MS are you using? or, is the new one even out yet?

 

I see you actually desoldered a 60 pin female from an EEC... how hard is it to work with in that form?

Oh and by the way, good job documenting the process. The more things like this people see, the warmer they will become to the idea of running one.

 

There isn't a TFI in this car. I think this year didn't have one from the factory.

The eec-iv connector did not want to be desoldered from the board so I ended up clipping the leads. I removed all of the pins that were unused to keep from crossing connections because the pins can be a little loose now that they aren't soldered to a board. I'll have to get pics of how I currently have it set up now that it's re-inforced a bit. I'll probably use some hot glue around the solder points now that I know I'm not going to re-wire. Changing to the original ECU takes a minute since I didn't change anything on the car. I'd recommend using the connector if you can get one.

Thanks to Zoah for giving me the fried eec to collect the parts from! Now I need to borrow your wideband o2.

 

Maybe a little OT but how much do you have into the entire system?

 

I bought the megasquirt($140.00) and megastim($40.00) from http://www.glensgarage.com/ . Then comes the misc parts like wires and a fried EEC (from ebay?) would cost no less than $5, I'm guessing. Most of the cost could be considered in the form of time because you'll be in the garage nights after work for weeks. Although we had a lot of pre-existing problems with the car that needed to be worked out. It's cheap to build, but takes time.

 

I believe the TFI is remote mounted somewhere. But as you say its for a friend, they probably already did away with it.

 

Yes the SN95 cars had the TFI on the passanger fender I think.


Its been awhile.

 

I don't quite understand where you are you getting the tach signal (for the megasquirt) from. Could you elaborate a little more on that? You have to be picking it up from either the distributor or the TFI module.... unless I'm missing something.


Yes, the tfi module is in passenger side inner fender (round hole) on a 94-95.

 

The car has a MSD 6A installed and I'm getting the tach signal directly from its tach out. The same place a rev limiter would get signal from.

 

Are you using Megasquirt to control spark?

 

No, I'm using the basic megasquirt and the MSD is on its own. I never made a megasquirt that does ignition control, yet.

 

I guess what I am missing here is how your telling either the MS or MSD where your engine is? I.E. what kind of trigger? Crank trigger, Hall effect in the dizzy?And how do you plan on controlling the curve?

 

Neither of us really know for sure. It just works. Are you suggesting that it isn't going to be able to advance the ignition?

 

Well, that's just it. I'm not really sure how the heck it working either, that's why I'm asking, cause it shouldn't be! If you are using just the basic MS code (not MS n Spark ) there is no provisions for any type of spark control. The MSD 6A is just an ignition box, i.e. it just shoots a spark whenever you (ecu, eec, MS, whatever) tells it too. So, the normal chain of events is: Ignition trigger (ie, hall effect in the dizzy) sends out a signal to the ecu (eec, MS, or whatever) that the engine is in "X" position, so then the ECU knows where exactly the engine is it's cycle (i.e. 20 degrees BTDC) and then the ECU tells the MSD to fire the coil. (the tach out on the MSD is just a regurgitated output of the ecu telling the MSD to fire.)

This is where I am getting confused with your setup... it's in this fooked up closed loop with nothing is telling anything where in the stroke the engine is. How it's working, I have no idea... How do you have the MSD hooked up more specifically?

"Are you suggesting that it isn't going to be able to advance the ignition?"

I don't see how it can.... there is nothing there to control it... That's why we use the MSnS-Extra code, because we can use that to control the spark curve.

 

I'm definitely going to figure this out now. Whatever existed in the car before I began it didn't use the EEC to control it. Maybe the car has the TFI in use. I've never worked on a Mustang before.

 

Jaeger, I have a question, I am ordering all my tuning and MS stuff today, I ordered my MS, flyback, DB7, and my LC-1 wideband. Well my question is should I still use my MSD Digi 6 or just use what I can from the MS in the TFI mode of the MS?

 

What do I need to do in order to get my MS to spark? Is it a firmware update and solder some more wiring in or do I need a different megasquirt?

 

This is what I have found to be the most rocksolid ignition setup:

Use your TFI PIP signal for the Megasquirts Tach input. It's a very clean signal.

Have your megasquirt trigger your MSD. (I personal have only seen and done this with MSD 6A's and 6AL's but a Digital 6 should work the same.)

That's it, that's all you need.. very simple, very clean and very reliable.


I have found that using the TFI module to trigger the coil has been slightly buggy for me personally. Also, with boosted aplications, it's a really good idea to use a ignition amplifier anyway... and this is definitely the way to do it.

Boost has all all of this stuff outlined on his website as to how to wire it up and everything. Check it out.

 

Awesome. Thanks for the help!