At worlds end with no spark

[734406pk]

                                                12 plus volts while cranking.  ??

Good point! Low voltage while cranking can cause no spark output also. I would want to see no less than 10.0 volts at the coil positive terminal. Less then 9.6v can really be a problem with electronic ignition (no output). See if you have healthy spark output at the coil wire when cranking... its a simple test. Have someone turn the key so you can see clearly. Don't get zapped!

[DocMel]

Thanks 

 Ill give the coil lead a check while actually cranking when I get off work today.   Ill also try the another spark plug wire and plug off a known running vehicle 

By the way, MSD just emailed me back: Confirmed that 3 wire, ready to run distros, are wired using the white wire

[HP_Cuda]

If you are using a mag pickup distrib make sure the white wire IS NOT GROUNDED. This is for theft deterrent and will not spark at all.

As for the wiring of the rest you can check my thread:

http://www.cuda-challenger.com/cc/index.php?topic=98345.msg968702#msg968702

[734406pk]

If you are using a mag pickup distrib make sure the white wire IS NOT GROUNDED. This is for theft deterrent and will not spark at all.

As for the wiring of the rest you can check my thread:

http://www.cuda-challenger.com/cc/index.php?topic=98345.msg968702#msg968702

  There was a bit of confusion earlier, but this Summit distributor is a "Ready to Run" type with it's own internal ignition amplifier inside, not a magnetic pick up type. The white wire would be connected to the coil output wire (just like a breaker point type) to trigger the MSD 6A box, if possible.  Its unclear if there is spark output at the coil while cranking the engine. 

[Strawdawg]

There was a bit of confusion earlier, but this Summit distributor is a "Ready to Run" type with it's own internal ignition amplifier inside, not a magnetic pick up type. The white wire would be connected to the coil output wire (just like a breaker point type) to trigger the MSD 6A box, if possible.  Its unclear if there is spark output at the coil while cranking the engine.

There is little that is clear   Problem of trying to sort things out long distance.

I think we both suggested earlier to omit the box and run it off the distributor.  It has been suggested, but, I will echo it-check the voltage going to to the + terminal of the the coil/red wire of the distributor while cranking the engine to make sure it is getting near 12 volts while the engine is turning over.

[DocMel]

Fellas   Thanks for sticking w/me:   

MSD tech says white wire hook up

I have today off/  So........

I will check with a known good spark plug and spark plug wire to see if I have spark while cranking

Will check spark at coil lead while cranking

Will install an additional ground strap, engine to frame

WIll post results 

[Strawdawg]

check the voltage at the coil plus terminal while cranking to see if it is adequate

[67vertman]

Sorry, that late to the party.......if I am correct Doc, you said this issue started with your original set-up, correct?

So your MSD must be wired correctly (as it ran before).  White wire to distro, blue and purple to an Ignition start and run 12 volt source, I run mine to the Brown wire on the ballast resistor.  Therefore if it is still wired the same you should have spark from the MSD, which you do, as well as spark to the coil and distributor cap.

You also replaced the Distro, which should have included a new cap and rotor correct? so that should eliminate those as potential trouble spots. However, don't count them out totally until you check them thoroughly for faults. 

As suggested, check the spark wires for electrical continuity. Daughtfull that they all failed at once but I would eliminate them as issues .

If you are still not getting spark to the plugs, I would find a distributor that you know works and swap it out.

[DocMel]

I'm not (and haven't been) running any of my old ignition (OEM) stuff, to include ballast resistor, so I am not sure where the blue and purple wire just mentioned would come into play

I just placed another ground strap on:  Still no spark at plugs

I also just tried a known constant hot to the little red wire off the MSD to ensure I has voltage while cranking:  Still no spark

I cant believe its this hard to narrow down so far 

Ill try a known good spark plug and wire next

I dont have an other known good distributor, so I cant try that option

[Strawdawg]

Use a meter and read the voltage to see what it reads while cranking

Sent from my LG-H810 using Tapatalk

[734406pk]

We are getting closer!
Some important info copied from an earlier post:::

::"I just tried wiring just using the distro with the MSD coil  (and no MSD box) by that diagram and still no spark at plugs"::

We know that the MSD 6A box triggers manually by grounding the white wire and there is spark output at the coil. The Summit RTR distributor should be able to do the same thing (while cranking). Wiring the coil direct to the Summit RTR distributor uses the internal amplifier. Many here agree: Checking spark output at the coil and supply voltage while cranking at the same time will test the distributor amplifier. 

[734406pk]

You want to leave the Summit RTR distributor connected directly to the coil. Check voltage at the coil positive terminal and spark output from the coil wire while cranking, using the distributor amp only. You may simply have a low voltage condition or a bad distributor amplifier.

[cudabob496]

some good electrical tips


http://www.moparaction.com/Tech/archive/roadside.html

[734406pk]

some good electrical tips


http://www.moparaction.com/Tech/archive/roadside.html

That's some good info for all Mopar owners!! I've had to do every one of those things over the years, and a few more under the worst possible conditions. Thank You!