I was going to visit a friend on a mid 60's degree blue afternoon. And car was running great. At the light where the car had been running perfectly, it just turned off. I mean just stopped cold. Would not crank to save my life.

I pushed her off, and noticed I still had 3 psi of fuel pressure and the car cranked well. Oil pressure and temp were spot on.

So this leave ONE thing. Electrical. I am betting my bottom dollar the ignition module in my Mallory just up and died for some unforseen and unpredictable reason. That is my first guess and where I will start the investigation.

However if you guys can come up with anything else, ANYTHING, let me know.

45 minutes later my baby was home off the flatbed. How humiliating. THe tow truck guy was extremely compassionate about the car and did not harm it thankfully, so kudos to him.

Pull a plug wire or coil wire and check for spark. Sounds like electrical to me.

Chuck

I suspect you're correct. Got a set of points to replace the optical module with?

it just turned off. I mean just stopped cold. Would not crank to save my life.

When you say it would not crank, do you mean that the starter will not engage? If that is the case I would look towards the fusible link or the ignition switch.

Yeah electrical.... I hope to be down in Houston for a few weeks in May...maybe we can rebuild a zx distributor some evening

Edited April 21, 201311 yr by Blue

Zedyone, coincidentally was just reading your old rebuild thread. Not the first time you had issues with that dizzy.

Why not just try going back to your original Pertronix for now?

Well I am going to run set of diagnostics on the module today. It is fairly straight forward. I have two other OEM dizzies with a pertronix in them that work fine. But I am almost positive it is the module... I will let you guys know when I start the diagnostics.

I plan to hook up a timing light and turn the car over just to see if I get a spark through. Then I will do a voltage trace to see what is getting what voltage. After that if all is normal, I will the ignition module test.

One thing I encountered is that there are two ignition modules that say they are direct drop in replacements for my 45 series mechancial advance Mallory. One is 90 bucks one is 45 bucks. They both say they are for replacement of your burnt out factory It is very strange.. One is model 905 one is model 6100M I may need to call Mallory for this.

Before you dump money and time into random problems, make certain you have power. Turn your key to IGN, and run a volt meter through all your fuses on both sides. They should all have 12V. If a lot of them DON'T have 12V, then it could indeed be either your ignition switch or a fusible link, as Gary suggested. I remember once having a fusible link go out on my '75 Z, and the car suddenly went stone dead as I coasted to the side of the road. It wouldn't crank or anything. I had to have it towed.

Copy that fastwoman.

I my trouble shooting plan will use extensive use of the voltmeter.

Okay, quick update

I checked the battery, it had 12.6 volts while the car was totally off.

With the ignition on, the fuel pump running I get 11.66 volts to the + side of the coil and the negative side of the coil.

My coil is still 1.5 Ohms across.

I hooked up the timing light to number one and cranked it with ZERO blinks.

I ran the check out for the Mallory called out in some instructions for trouble shooting Mallory Ignition Coils.. here

1. Remove Cap & Rotor

2. Turn Ignition Key ON

3. Is there Battery Voltage (+/- 14v) on the POSITIVE side of the coil? YES = GOOD!

4. Is there Battery Voltage (+/- 14v) on the NEGATIVE side of the coil? YES = GOOD! NO or Much Less Than Positive Side of Coil = BAD!

5. Voltage Drop Test - Voltmeter still on Negative side of coil. Voltage Drops BELOW 2.0v when the optic is blocked= GOOD! NO Drop = BAD!

6. Voltage RECOVERS to BATTERY VOLTAGE after unblocking the optic? YES = GOOD NO = BAD

I failed number 5.

When blocking my optic, nothing changed at all. So poof there went the Ignition module. Now the question is why

Steve,

As you know I run a similar setup in my car and have always been concerned about the reputation that the ignition modules have for blowing out due to voltage spikes. Based on that I installed a Mallory surge supressor / power filter quite some time ago and have never had an issue. It is a direct connect to the mallory distributor circuit and comes with all of the right connectors to install it inline with the Mallory Unilite. Part number is Mallory 29371.

Also I had a similar incident as you about 9 months ago (actuall shortly before the rally). I was headed to downtown Austin for a photo shoot that I had been invited to by Hagerty Insurance and my car just died on Mopac / Loop 1. Not a great place to be on a Monday Am at about 9:30.

In any case it was definitely something electrical and once it was towed home I zeroed in on the Mallory module as well as the Mallory MSD ignition system. Long story short, I went to a local speed shop and picked up a real MSD ignition as well as a new Mallory module (which they surprisingly had on the shelf). It turned out to be the 6100M. The store owner told me that the actual replacement part for my dizzy was something different (I believe it may have been the 905) but that this module was identical and 1/2 the price. So if you need to get one the 6100M will probably do the trick. I carry with me at all times for a spare but have never had to use it.

As it turns out, it was not the module that was may issue (a fuse if you can believe that) and so I never had a chance to try it, but it looks identical to the original one in the Unlite.

I'm very happy with my Unilite and have never had any problems, but perhaps the inclusion of the power surge module has saved the day for me.

Hope this helps you out.

Mike.

It always amazes me why Z owners try to change things that work so well.....the stock point distributers work so well.....why futz with them! The only two times I can remember losing everything in a Z was when number 1, I lost a fusible link....number 2, I had a loose wire on the distributor. Zedy .....Check the crimp on your distributor connections and your fusible link...if that isn't the problem, bolt on one of those old fashioned stock distributors and see if that fixes the problem......IMO