Escort GT and Protege distributor WILL work in an MX3 RS

[lazzer408]

I just got finished wiring up a Escort GT distributor into my RS. The original all-in-one distributor was misfiring bad under heavy load at low rpm. Now she runs like a top. The GT's distributor is optical it looks like. The RS's was magnetic. Either way I bet the output is a square wave for either. The stock RS ECU seems to deal with the signals fine. The finished install is clean. The GT's coil/ignitor/fuse-panel bracket fits. From the distributor plug to the RS harness looks like oem. The only thing different is the harness I made to go from there to the coil/ignitor/capacitor. I believe it was 4 wires in it. It's all taped up now.

Has anyone made a write-up on this? If not I'll see if I can find some time to do one.

[npspears]

The disty for the 4 cyl mx-3 is different between the SOHC and the DOHC. I believe there are also two different types of BP distys (maybe more). You have to find the right BP disty to work in your mx-3. In other words not all BP distys will work in your mx-3. I know from experience.

[lazzer408]

I have a dohc '94 1.6 and the distributor I used is from a '92 escort 1.8. It took rewiring to make it work. Every BP I saw in the yard had the same distributor I used.

[Savin]

95 protege and sephia disties (1.8L of course) will work with the DOHC B6. 94 and ealier protege and escort GT (not sure on years for escort) disties will work with the SOHC B6.

From what I have read, the only disties from the sephia and protege that will work on the DOHC is from 95. After 95 I believe it switched over to OBDII and the disties changed dramatically.

These will match up directly to the B6's. The protege and sephia's of 95 have the exact same disty as the DOHC B6.

[4gotn]

im up to the wiring part
what exactly did you do to wire the ignition module and did you use the stock module or did you find another type....i was looking at an external module off a miata but it may not work being as it was cop...????

[lazzer408]

I printed the escort's and mx3s wiring diagrams and just matched signal for signal. I used the escort ignitor and coil as well as the small filter capacitor mounted under one of the coil bracket bolts. What I did was wire up the escort side of things first. This will have 4 wires total that run from the coil/cap/ignitor on the fender over to the harness that ran to the stock distributor. It is power, ground, trigger, and tach. The 4 wires from the escort distributor are the 2 cas signals, power, and ground. Using the wiring diagrams from both cars I was able to splice it all up. I should mention I cut the escort's harness about a foot back so I'd have enough lenght to the wire.

I'll draw up the diagram when I get a chance but it's easy. The only thing that was hit or miss was the 2 cas signals. The diagrams didn't explain which is which. I tried them one way and when that didnt work I swapped them and it fired right up.

[4gotn]

please make some pics or something

[lazzer408]

I hope this pic turns out. I have both schematics in my hands and drew this up for you guys the same way it is in my car. I'm sorry I don't have the info on which BP cas wires goes to which B6 cas wires. I already taped up my harness. If it doesn't work, swap them as noted. Some colors match up. Some don't. I drew the coil/cap/ignitor on the right side as if you were looking into the engine bay. You can wire that up on it's own and run the 4 wire harness you just made over to the MX3's harness at the back of the head. Cut the 2 distributor plugs off and wire away. The 1k resistor can be found at Radioshack. #271-1321 $0.99. It may look complicated at first. Just print it and connect each wire one-by-one and cross them off as you go. In no time you'll be done and have a much more reliable and stronger ignition system and get rid of that pos all-in-one distributor.

When you go to the junkyard for the parts don't forget the connectors and leave some wire to work with.

P.S. This was for my '94. I don't know if all 4cyl MX-3s are the same. All parts used were from a 92 Escort GT.

[lazzer408]

If you find this usefull and it saved you $100s on a distributer, pm me for my paypal address.

I was the one who came up with the coil-over-plug conversion for the Miata using Toyota coils. Unfortunatly I don't have an easy solution to do COP on the MX-3. There is only one trigger signal from the ECU. A Miata ECU swap could do it though. Good for the BP guys.

[4gotn]

forgive me if i sound ignorant but i dont really have much time to indulge myself
i think i see where your going with this as far as the coil and module go but where are a b c d running on the disty?????
that and is there a capacitor already on the mx3 or is this the resistor?

[4gotn]

nm about the abcd im looking at a pic of the disty and i see how that gos into the module but where do these three wires labeled ignitor go.. i work in a parts store and ive heard the coil be called coil and ignitor but i dont understand why im running two??????

[lazzer408]

4gotn - The wires from the distributor do not go into any module. Of the 4, 2 are power and ground and the other 2 are the 2 cas signals to the ECU. The coil is the transformer that steps 12v to 25-50kv. The ignitor is the low side switch (transistor) that charges the primary side winding. It conducts when a trigger pulse is recieved from the ECU. The ignitor has 3 wires. Ground, Coil, and the Trigger signal that causes the ignitor to connect the other two.

The B6s original capacitor was mounted to the distributor. It was removed. The resistor for the tach was internal to the original distributor as well.

The wiring shown is installed in my car and working great. I think I paid $25 for the coil/ignitor/cap on the bracket from the junkyard. I already had the distributor from the BP engine. When I first fired up the BP in the car, I was using the B6's all-in-one distributor and it had the same mis-firing problem the original B6 had. Once I switched to this ignition system all my ignition related problems went away.

[4gotn]

ok im following you so far
i got rid of my sohc so im trying to get this straight in my head
i see how you ran the disty/module in the disty but im not sure what you meen with this ignitor business
as far as i know from exp the module tells the coil when to fire, the module is in the disty (the 4 wire) so where is this ignitor (3wire)???

[lazzer408]

There is no module in the distributer I have. Mine looks like the one in your picture. They have 2 position sensors but that's it. One is 4 pulses per rev of the cam and the other is a single homing pulse for tdc. Both signals go to the ECU and the ECU sends a signal to the ignitor bassed off it's timing map. The ignitor then fires the ignition coil.

[lazzer408]

Looks like this. It is mounted below the ignition coil on the same bracket. Drivers side inner fender on Escort GT and Protege.