I installed a used digital 6 box with my current msd distributor. The wire connector for dizzy to box was cut off so I had to connect the wires on my own and I figured purple matches purple but was wrong. With the wires connected incorrectly the car would start but wouldn't idle. I swapped the wires and now it won't even start. I checked the timing while cranking the motor and got 5*, 28*, 12*, and -2*.

The box doesn't blink any codes. The light comes on solid when ignition is turned on, then blinks when cranking, indicating each break in the pickup, then the light is out after cranking which the msd rep says is normal. He said having the wires backwards would not hurt the box.

I can't use the distributor alone, it has to be hooked up to a box, so I don't know how I can tell if its a problem with the box or the dizzy.

The wires are hooked up correctly and the green wire is cut per directions for use with an msd distributor.

Suggestions?

 

Remember that "MSD" is the acronym for multiple spark discharge. If there are multiple sparks to every plug on every cycle, timing is inherently difficult. You really need to look at the trigger pulse of the distributor instead of the resultant secondary spark output. Just connect your oscilloscope to the MDS primary and rig a timed trigger to a 741 op amp, then use it to drive your timing lamp and call it good.

Another method would be to build a high-pass filter for your timing light to only recognize the leading edge of the first input at about a 4 Hz rate so that it ignores the trailing pulses. That should allow your timing light to work effectively up to about 1,800 RPM.

Piece of cake.

 

Visit the MSD tech forum, I learned allot in there.

#1 is to use a cheap reg timing light, new fancy digital lights or dialback timing lights can't deal with the dual spark right.

Lucky me, I had the cheap-o kind.

2nd is did you route all the wires together?

Wires come out of each end of the box on purpose, as to close they can have RF cross talk. [they said 6-8 in apart min]

Which lucky me I did, ran them all together.

Once I ran the coil wires the long way around to the coil, instead of across the motor with the trigger wires, Walla, all was well again.

And lucky again me mine was also used, $15

 

An no offence to Vader but you want to be able to check timing above 1800, unless your all in at 1800 or less. You want to set your total at the RPM where your all in. Less playing around to get the most timing without ping. Though all in around 1800 wouldn't be bad if that were so.


Now to use a regular timing light you need a timing tape or need to know your balancer size.

Mine is a 6 3/4" in diameter one, so I use this below.

"To do this with a conventional timing light, you need to make a 30* mark on your balancer. With a 6 3/4" in diameter balancer. Circumference (360*) of a circle is pi(3.14) X diameter. 6.75 X 3.14 = 21.195"/12 = 1.76" (30*). Looking at the engine from the front, measure exactly 1 3/4" clockwise around the balancer, and make a second mark. This is your 30* mark. Connect up your timing light, and watch your 30* mark as you increase the RPM's. At some point, your 30* mark will stop rising, and move no higher. This is the RPM, where all of your mechanical advance is in. AKA all in"

Always remember to subtract the initial timing from total.

If your going for a total of 32-36 and have an initial of 12.......
Setting it at the 30* mark you made will be 42 total.

Useing a regular old timing light.

 

If you make a mark every 1/4" start with 0 [6 3/4" in diameter balancer]

8 marks
[rounded up to nearest dec.]

1- 0*
2-4.29*
3-8.58*
4-12.86*
5-17.15*
6-21.43*
7-25.12*
8-30*

If your going for a total of 32 and have an initial of 12, you go for the 20 range at the RPM you were all in at.

Then raise n lower as needed to get the most with out ping.

 

I did have the wires routed together, but it seems the real problem was the coil was leaking oil out the top around the terminal screw. It had soaked up into the wire. I made a new coil wire and tightened the screw, and all was good. It isn't leaking anymore.

I also did have the pickup and coil wires running close. Fixed that. Took me a long time to figure this problem out. Coil had maybe running 20 hours on it.

 

Here are the only 4 oil filled coils to use.

NAPA IC12
MSD 8200
Summit G5215
Carquest 26189

How could that be, only 4. I know the ex GM tech engineere who designed the Ign system for GM cars, he still builds for race teams, and only those 4 coils pass his spin test for Ign parts for a reliable spark across the whole RPM band.

 

good to know

 

The MSD n Summit are the same part, made in Andover IN.
both chrome & Summit is cheaper

Other two have the same spec's and are black.
Not sure if they are made in Andover or Mexico.

I believe he test spins all parts to 12-14,000rpm
Which may be over kill for some engines and many will chime in and say I used this n that coil n it worked fine. But ill only use one of them 4 on my stuff.

Its like having Bill Gates or Steve Jobs tweaking your computer.
You don't question it, just listen and do it