Update - Thanks for Help with HEI mod wiring on 94 MX-3

[neumann]

Sorry to be an idiot but I am putting my MX-3 back on the road for the Winter. In april the disty gave out. I am following the HEI mod instructions that Gro Harlem did at Clubprotege.

Car is a 1994 MX-3 GS.

The issue is getting the internal coil out of the equation. I am okay with either removing or disconnecting the stock coil but can't figure out exactly what I need to do. The pics in the mod faq don't exactly what I see, and I am hesitant to just guess. I neither see what screws I would have to disconnect to remove the entire coil, nor do i see the "strap" leading to the 3 pin connector as depicted here:



I do see an exposed bayonet connector in essentially the same place as the screw in the above image, but there is not an obvious connection back to the 3 pin connector. It would make sense. Do I just cover that hole where the connector is with ATV sealant?

Any guidance , pointers, pictures, reassurance, slap upside the head, HEI for dummies excerpts etc would be appreciated.

Peter

[solo_ryder]

That is because you have a 94, the disty is different. I tried a HEI on the 94 and it did not work. Are you sure your disty is shot? You can measure resistance in the primary and secondary coil and see what you get..

[neumann]

Hmm, have never heard of it note being supported on the 1994 GS the instructions specifically say 94 GS is included. I don't doubt that there are different distys potentially on these machines but it wn't work at all.

What I have appears to be a slight variation on the disty as pictured. The difference is I don't have that strap clearly leading to a screw.

And I don't see any addition fasterners that are holding the coil in. If I can find a camera and get a chance I will grab pics

Edit

Okay. I had a look and my disty looks more like the pics in the 1995 shop manual than the 1992 shop manual. The area where I am expecting to see the "strap" and Screw is underneath the ignitor as pictured in the 95 shop manual
http://www.mx-3.com/manuals/showimg.php ... /G-030.gif" onclick="window.open(this.href);return false;

but all i see is this bayonet type connector and there is a flat metal plate underneath the ignitor with no obvious screws to undo to remove the internal coil

[Flyer]

Hold on, so you are telling me that anyone with a 94+ GS is SOL when it comes to this?

[wytbishop]

no...the basic operation of the ignition is the same. Some wires are different and the cap is cofigured differently, but anyone can do the HEI mod. I will have to look through the diagrams again to sort it out.

[solo_ryder]

No, what I am saying is that the 94 uses a SPECIFIC disty SPECIFIC only to the 94 mx3 only. probes, mx6 and what not do not use the 94 disty which is labeled as a TOT51717. Apparently the coil in these distys are very strong and do not fail, hence why we never see any issues with 94 distys or posts on how to do a HEI on them. 95 and 96's may use different distys (i know that OBDII users have a different setup).

There is no strap in the 94 disty. If you take it all apart you will see a "chip" looking connector with 3 small metal straps extending to the coil, this is where cutting something off may work. That is as far as I got with my attempt. Wyt, if you can make this work then that is great but its not the same as what is in Gro's writeup. Even the 3 pin connector is wired differently, the IGN + and IGN- are in different locations on the pinout.

[wytbishop]

I never did the mod on my 94', but I was about to when I got the 93' and I had it all worked out. I am not a believer in removing the coil and igniter from the stock disty. It isn't necessary. Once you know which wire does what, you're golden.

[neumann]

Further on my attempt to do the HEI and external coil on my 1994 MX-3 GS 1.8L K8. Everything was going swimmingly following wil's instructions until I was getting to the point of disconnecting the old coil. The problem is that my disty does not look like the one in his how to.

It does look like the 1995 Probe v6 one in 96prizobe's post in a thread over at probetalk:
http://forums.probetalk.com/showthread.php?t=1701217992" onclick="window.open(this.href);return false;

and the pics Omaha95PGT posted in:
http://forums.probetalk.com/showthread.php?t=1701081990" onclick="window.open(this.href);return false;

so it would appear that at least some canadian 94 MX-3 GS have 95+ style distys. Not sure how exactly the matrix of MX-3, Probe, Model Year, Geo sold etc works out but I think I am down to two issues.

1. Trying to confirm the wiring, particularly on the 3 pin connector which may be different from the 92-94 MX-3 or the later K series on 96-97 probes.
2. Identifying what exactly i have to do to disconnect the old coil. eg am I actually supposed to take a dremel tool and saw off a portion of the spark tower as shown in this pic with the brass tip:

which in my disty fits into the hole in the bottom of the cap which I have already gummed up with silicon as per the example in this pic

at the bottom where you see the blue goo in the hole.

Any pointers?

I am at the point of no return if i start cutting of pieces.

Many thanks for your help and the fine work in posting your expertise

[neumann]

Aieeeeeeeeeeeeee,

I am sooooo confused, apart from the "what disty is in the 1994 MX-3 GS?" I get to massive confusion about the wiring and pin arrangement of the 3 pin connector.

Not sure if this means anything to anyone but my Disty cap inside is marked as Part 411 1 423.

Looking at the 1995 Probe reference (since this appears to be similar to the disty in the 95 probe or the 95 MX-3 and not like the 92-93 MX-3)



Apologize for the formatting but Summarizing the description as
1995 Probe
Pin
1 Color: Black/Pink, Function: Power (Hot in Start or run)
2 Color: Yellow/Green, Function: Tachometer Signal (Ignition ground)
3 Color: Yellow/Blue, Function: Tachometer Output

Compared to instructions from the HEI reference docs at Clubprotege (section 6) http://www.clubprotege.com/wil/howto/hei/index.htm" onclick="window.open(this.href);return false;
HEI mod ref erence how to
Pin
1 Color: Red, Function: Ignition coil Negative
2 Color: Yellow/Blue , Function: Tachometer signal from ignition coil
3 Color: Blue, Function: Ignition coil Positive
Note: The reference at clubprotege appears to describe the pin layout for both 3 pin and 6 pin connectors in reverse, so i have realigned to fit the same foramt as used above – or am i nuts? eg look at the description of the positioning of the Orange wire on the 6 pin connector. I am not sure how much of this is orientation vs. actual wiring changes. My initial reaction was to take position over wire color. It was only recently that it occurred to me that the above docs may have inverted position or color description.

So where I was with this,based on the wiring I see on my car:

My 1994 MX-3 status and assumptions
Pin
1 Color: Blue, Function: Ignition coil Positive Connect to Coil + and HEI Module PIN B
2 Color: Red, Function: Tachometer signal from ignition coil Insert 1kOhm resistor and connect to wire running to Coil Negative
3 Color: Yellow/Blue, Function: Ignition coil Negative Connect to Coil - and HEI Module PIN C


I have seen other references to changes in pin outs on 95+ distys (which again resemble my 1994 more than the 92-93 depicted) and don't know what to believe now. I don't want to hack in and out of wires over again.

Help, anyone?

[solo_ryder]

Aieeeeeeeeeeeeee,

I am sooooo confused, apart from the "what disty is in the 1994 MX-3 GS?" I get to massive confusion about the wiring and pin arrangement of the 3 pin connector.

My 1994 MX-3 status and assumptions
Pin
1 Color: Blue, Function: Ignition coil Positive Connect to Coil + and HEI Module PIN B
2 Color: Red, Function: Tachometer signal from ignition coil Insert 1kOhm resistor and connect to wire running to Coil Negative
3 Color: Yellow/Blue, Function: Ignition coil Negative Connect to Coil - and HEI Module PIN C

I have said this before but noone seems to listen (not referring to you) the 94 MX3 has a disty that is SPECIFIC to that year and ONLY to the mx3. It is a TOT51717 serial disty.

Blue = IG+ (as tested with a test light by me)
Red = IG-
Yellow/Blue = Tach signal

The only difference is the location of the wires on the 94 disty, they are all switched around.

[neumann]

I have said this before but noone seems to listen (not referring to you) the 94 MX3 has a disty that is SPECIFIC to that year and ONLY to the mx3. It is a TOT51717 serial disty.

Blue = IG+ (as tested with a test light by me)
Red = IG-
Yellow/Blue = Tach signal

The only difference is the location of the wires on the 94 disty, they are all switched around.

Solo

Thanks. I will try this pattern. As you note the distributor on this car seems to be not quite the same but very close to the 95+ disty (I would not likely distinguish it until getting inside and taking off the rotor).

I was surprised that despite the commonality of the 94 and all the posts on HEI mods that this was only noted by a couple of people. Also was just getting increasingly confused by different orientations of pin layout descriptions, differences between model years etc.

Any advice on the disconnect of the internal coil? The Probe guys appear to be saying take a dremel tool and hack off the end of the spark tower (want to be more sure before i leap) and fill in the spark tower hole in the cap with silicon (done).

Thanks

[solo_ryder]

Not sure about that, but the 94 probe disty is different. Apparently the internal ignitor/coil is never really supposed to break down on that disty

[shameem]

Go with the wire colors in the 3 pin plug - blue is switched +ve, Yel/Blu goes to the tach and the red is coil -ve (not same as ground). In 94 distys the wire colors are similar but the wire positions are different.

To "isolate" the stock coil - hack off the tower thing and dont plug the 3pin plug into the disty.
To "isolate" the stock ignitor - cut the orange wire and the wire next to it (black/green i think) in the other (6pin) connector.

[neumann]

Had a brief delay as the battery would not take a charge (5.5 years old, sitting for the last couple of months) anyhow now that it is tatally freezing in my garage i tossed in a battery and wired it up as per Shameem's advice:

Go with the wire colors in the 3 pin plug - blue is switched +ve, Yel/Blu goes to the tach and the red is coil -ve (not same as ground). In 94 distys the wire colors are similar but the wire positions are different.

To "isolate" the stock coil - hack off the tower thing and dont plug the 3pin plug into the disty.

and I have connected the 6 plug to the disty. I have not taken this final leap:

To "isolate" the stock ignitor - cut the orange wire and the wire next to it (black/green i think) in the other (6pin) connector.

since I have seen so much conflicting information. I have tapped into the orange wire and run a connection off to the HEI pin G, but I have not cut the wire at the 6 pin plug. Also it was my understanding that the black green wire next to it was not used.

Before I cut anything I was looking for reassurance.

Due to my delays I forgot where i was and tried starting. Not much the first couple of tries, then it strated turning over and sounded as thought it was about to catch. I think I am getting spark but still not there yet.

[neumann]

Thanks to all for the help. I have everything wired up and warmed the engine up and then drove it about a mile. Parking brake was stuck so I had to get it loose. It ran fine but then started running a bit rough, dropped to extremely low speed at idle. Eventually stalled. CEL light came on. It started again but stalled more.

Anyhow, reallly reeally dumb question - where does the orange wire need to be cut? eg I have splice in with an IDC terminal, so do i cut the orange wire:
between the IDC tap and the 6 pin connector to the disty (effectively so that nothing is donnected to the orange wire going into the 6 pin connector)
or
on the other side of the IDC tap so that the wire leading from pin G of the HEI connects into the orange wire of the 6 pin connector but the orange wire on the other side is going nowhere