Cant start new motor!

[Darrman]

I have been stumped by this one, I had a Duraspark setup in my truck for my 390, I replaced everything with brand new parts and couldnt get it to start. I finally gave up and went back to a points distributor and matching coil, and of course am having the same problem.
Ok, so here are the symptoms, the coil is getting 12.60 volts as long as the distributon neg wire is NOT plugged in, as soon as I plug it in, the voltage drops to 6.40 and I cant see this being right. There IS spark, but its pretty weak looking, whitish yellow. Everything under the hood is new, except for the voltage regulator, could this have something to do with it?
Hopefully someone can help me out with this, I need to get this motor started!
Thanks for any help!

[basketcase0302]

Darrman,

6.4 sounds a little low to me, I believe it should be more around 9 volts or so.
Maybe someone else can pipe in soon on that reading.

Is the coil new? Do you have another coil you could replace it with?

Basketcase

[Darrman]

The coil is new, and its the third one I have tried with the same result.

[Thunderfoot]

With the points closed it will read 6-9 volts...

Some of this you may have done but I will go over it again as a check.

If you put a test light on the Positive of the coil and turn the motor over you should see it pulsate or flash for each spark of the motor, if it doesn't then you have a problem with the points or the (-) wire from the coil going to them, or the condenser... (however you said you had spark so I think this is ok..)

After that, I would go back to the start and double check that the distributor is in correctly and the plug wires are correct. Be sure that you pull the #1 plug and turn the motor over by hand as you hold your finger over the hole and the compression starts to push your finger off the hole. Then keep turning the motor over until it stops blowing and you should be at TDC on your timing marks. If you back this up 6-10 degrees from TDC and put your distributor in with the rotor pointing at #1 plug wire it should be good to get it started.

Then be sure you have gas in the carb and that you can see it coming out of the accelerator when you move the throttle.

If you have any questions let us know.

Others may have some tips for you as well...

[Jake11]

Weak spark = bad coil, or coil wire.
Try using a jumper to the + side of the coil to take the rest of the wiring out of the picture.

[Darrman]

Thanks for the help fellas, got er started finally today. I guess I had the timing way off, did the whole procedure for installing the dizzy and she fired right up.
BTW, a 390 is amazingly loud in a garage with open headers, , damn near was deaf afterward.
Thanks again!

[DGrant09]

Isn't it a Sweeeet sound!!

Congrats!