pics of the 72 as promised but I have questions Options

[superdad88]

Ok here are the pics of the car that I am going to buy. I worked on getting it running and I believe I think I know what's wrong with it.

I wasnt getting any spark to the spark plugs. So I traced it all the way back to the MSD. I believe the MSD is bad but wanted to ask you guys for sure before I go and spend 300 bucks.

There is a gold box to the right of the MSD, not sure what this is. I did check the transformer and I am getting voltage from there. I checked the MSD as per their website and from what I can tell its not providing spark.

But what is the gold box? Wanted to make sure it might be something simple and I am missing it before I spent the 300 bucks.

[Mike Bellis]

You should be able to bypass the MSD and get it to run. You don;t need it in the system.

[TheCabinetmaker]

I'm a fuel injection guy, so don't know much about the msd boxes. That junction block does not look right to me. Where do all those wires go? Can you stand back and get some overall shots. Wide angle? How bout some shots of the deep hole below the battery. Also a good shot of the relay board without the cover.

Nice looking car. Pedrini's are my favorite stock wheels. Everyone has Fuchs.

[Cairo94507]

None of those three boxes look original to me. But that is a nice looking car and I like the wheels too. Good luck.

[superdad88]

You should be able to bypass the MSD and get it to run. You don;t need it in the system.

How do I by pass the MSD? As for the wires and where they go.

Out of the MSD 2 of the wires go to the coil.

One red wire goes to the starter, one is grounded.

A couple go up to the junction box and goes into the transformer and to that gold looking box.

This is from memory. Which kinda sucks lol

I cant get any more pics until Monday. Its over in my uncles wearhouse for his pawnshop and he is closed on Sundays. (IMG:style_emoticons/default/sad.gif)

[ArtechnikA]

The gold box looks like yet another CDI box, but it may be the power supply for some kind of points-conversion thing.

I don't like MSD's - had too many of them fail.
However - they're only about $175 at Summit and FLAPS everywhere so don't ahop anywhere they want you to spend $300 for one.

All you 'need' for a Kettering ignition system is points, condenser, and coil.

The hookup on the MSD looks about right. the 'transformer' is actually a loading coil (half a transformer) that's used to trigger the tach. There are other, better ways to trigger the tach.

Have a look inside the distributor and see of you've got actual points in there or something else - maybe an optical pickup and shutter wheel, maybe some kind of magnetic trigger. Where you go next depends on what we're working with. See if you still have a condenser attached to the dizzy. It might not be connected (not used with CDI) but we need a better idea of what pieces you have to work with.

We'll get you spark, and then you can decide what 'modern upgrades' you want to progress to.

[superdad88]

Can you point me in a direction to where some pics of the different types of points your talking about?

I remember what it looks like under the cap but dont know where to start explaining what it looks like. Because I dont know the jargon.

[SLITS]

The gold boxlooks like a Crane XR700 or XR3000 optical trigger box (points replacement mechanism). You will find a trigger wheel and optical pickup inside the distributor.

Gold acts as a trigger mechanism to fire the msd unit.

The gold unit can be used alone with a standard blue bosch coil instead of the msd unit.

[superdad88]

Ok so your saying disconnect the MSD unit and install a bosch coil? but wouldnt I also have to replace the distributor and points?

[ArtechnikA]

what coil do you have now? might be OK.
The points-replacement unit (gold box) is now youy points.
Verify it's working, then go with it...

[superdad88]

not sure what points i have now and dang i wish i could get a pic. But when i took the cap off there was the rotor and on the side there was something that looks like it has a wire attached to it. At first glace it looked like it was melted but when I looked closer it's supose to look like that.

[Mike Bellis]

Here is the basic MSD wiring. If you take the trigger input and put it to the output and remove the MSD you will prove or disprove the MSD working.

[Prospectfarms]

Kg6dxn wrote:
"Here is the basic MSD wiring. If you take the trigger input and put it to the output and remove the MSD you will prove or disprove the MSD working."

Would you mind restating that?:

Is the "trigger input" the + or - wire described as the "original coil wire" on the diagram?

What/where is the trigger "output" you've referenced?

I think you're suggesting he disconnect the four main wires coming from the MSD, then reconnect the "original coil wires" to the coil? Would that be sufficient to get a spark at a plug assuming the remaining components are operating?

Could someone tell Superdad88 (and me) what they think the after marked parts in his ignition system consists of? For example, it sounds to me like there is an optical trigger in the distributor that is controlled by electronic timing which fires some sort of CDI (gold box?) That's just a shot in the dark since I've never used any of those. Thanks.

BTW, superdad, nice looking car!

[ArtechnikA]

Would you mind restating that?:

It's stated pretty plainly on the MSD diagram, but to 'revert', you'd take the wires from the MSD attached the coil and remove them. Then take the 'original coil wires' and reattach them to the coil. Switched +12 from the ignition to Terminal 15 (+). Wire from the points to Terminal 1 (-).

I think you're suggesting he disconnect the four main wires coming from the MSD, then reconnect the "original coil wires" to the coil?

yes.

Could someone tell Superdad88 (and me) what they think the after marked parts in his ignition system consists of? For example, it sounds to me like there is an optical trigger in the distributor that is controlled by electronic timing which fires some sort of CDI (gold box?)

The parts of the puzzle are in the thread but not all the dots are connected...

The gold box is a points replacement. It, too, could be defective - or the actual optical trigger in the distributor. Or any of the connections could be bad...

Basically - two wires from the gold box talk to the optical trigger unit in the dizzy. It'll also have power and ground. And an output wire that acts just like the wire from the points. This is now "original points wire" if you're an MSD.

For all those connections, the MSD hookup is simple, like it shows. High-current power and good ground. Two wires to coil to make spark. One wire from the points. And what used to be switched +12 basically becomes a 'power switch' for the MSD. Complicated only slightly by the fact that it's also the +12 for the points replacement module (gold box).

The MSD can be tested independently. Power on, intermittently ground the 'points wire.' You should make sparks.

The points replacement can also be tested separately with a meter.

[SLITS]

With a points / coil system, the points open to collapse the field in the coil to produce a spark to the plug. Points wear, corrode, pit, closing the gap set and decreasing the time for saturation of the secondary winding in the coil .... known as dwell. Decreased dwell time ... decreased spark energy. This wear also changes the timing of the engine.

Points replacement ... cheap so to speak:

Two types ... magnetic (Hall effect) and optical triggers .... The magnetic ones have magnets embedded in a device that goes over the point cam of the dizzy with a module that "senses" the passing of the magnets and causes collapse of the secondary coil windings, producing a spark.

Optical is a light beam between two LEDs. Slots in the trigger wheel allow the light to pass, producing a trigger to collapse the secondary windings in the coil.

Both systems produce maximum dwell time for saturation of the coil = best spark energy.

The optical systems generally have a trigger box, which is nothing more than a capacitor that charges rapidly. When triggered, it shoots more stable voltage to the coil than a conventional system, supposedly insuring a maximum spark energy to the plugs.

The MSD, Crane Hy-Fire, and I don't remember the rest of them are basically the same .... They trigger a coil or a transformer (Porsche CDI is a transformer ... the CDI unit shoots 400 Volts to the "coil" which is why they won't work with a standard coil). High energy coils are used with these systems for hotter spark. A conventional coil can overheat and explode if fed to much voltage.

So, in this case, the PO was using an optical trigger to trigger the MSD which fires the coil ... coil is probably matched to the MSD for higher spark energy ... actually just redundancy as the MSD could have been triggered with points (and all the associated problems with points ... variable dwell, incorrect timing due to wear).

If the Gold box were hooked directly to a "standard" coil or a "hot" coil, the system would produce spark, reliably without varying dwell or timing as there is nothing to wear.

Oh well .... more coffee. Google Crane XR700 and you will find installation instructions for it. Pretty simple.

[superdad88]

Acording to some pics i have seen it looks like it has an optical trigger under the cap.

[superdad88]

Would you mind restating that?:

The MSD can be tested independently. Power on, intermittently ground the 'points wire.' You should make sparks.

The points replacement can also be tested separately with a meter.

That's how I checked to see if the MSD was bad. I didnt get any spark.

[SLITS]

Either box or both could be no good. If you aren't getting spark at the plugs when cranking the engine, one or both could be bad (Yes, the Crane Trigger Boxes fail too!).

Regardless, buy the car ... it looks really good. You can always go back to a points setup fairly cheaply to get it running.

Unless someone does it before tonight, I will try to image the Crane system and post the images.

[superdad88]

I paid him for it yesterday. (IMG:style_emoticons/default/smile.gif) with the understanding that what ever it takes to get it running we split the bill down the middle.

Wish you guys were closer. Beer and pizza would be on me.

[ArtechnikA]

That's how I checked to see if the MSD was bad. I didnt get any spark.

That's how Autotronic suggests it be tested.
Of course, that test is only valid if there is +12 at both the places it's supposed to be. It's really important that the 'heavy' wires go directly to a high-current source, like the battery. All multi-spark systems generate a lot of energy - much more than can be delivered through the switched ignition lead.

But - could also be that the 'coil' - which has not been seen or described - is bad.

Be advised that anything on the output side of the MSD is potentially lethal voltage - test with care !

If you wanted to continue with the MSD, the Summit MSD clone, the Crane HyFire, or some other CDI box, I'd recommend getting either a Crane high output pulse transformer, or an MSD 'High Vibration' Blaster-2. (The 'High Vibration' Blaster is the only MSD-brand 'coil' that can be mounted in any orientation...)

If you want to just get it running, and deal with CDI later, a Bosch Blue will do nicely for now. You'll also need a condenser, which may or may not still be attached to your dizzy. (Actually - if you keep the Crane points replacement module, you may not need the condenser either...)

You might also not get a spark if the rotor isn't pointing 'close' to a spark plug tower. with 6's and 8's there's usually one 'close enough' all the time, but /4's towers are pretty far apart...

The advantage to keeping points with CDI is that they draw so little current that they don't arc and burn. They are still subject to rubbing-block wear tho. If the Crane is working, I'd keep it.