Technical Baby hemi starting problem

Looking for some guidance. I've got an old 55' 270 hemi that I'm trying to start outside of the vehicle. I'm not getting proper voltage to the - terminal on the coil. On the positive side I get 6 volts (it's a 6 volt system), but less than a volt on the + coil terminal. When I crank the motor, the voltage doesn't change on the + terminal. Long story short, I'm not getting any spark anywhere. Any ideas?

For wiring, I've got a wire straight from the + on the battery to the + on the coil. I've got the distributor wire to the - on the coil. Then I just jump the battery to the starter. Any other ignition relays, solenoids, etc. are not wired up as it would be in the car.

 

Try a new positive wire from battery to coil.

 

I don't think you are supposed to get full voltage on the negative coil terminal. Check that your points are opening and set at the proper gap. Oh and I think you have a typo in your question.

 

It's a brand new wire. So are all the wires on the top of the distributor.

 

I set the dual points at 0.017. But even when cranking, there's no change in voltage on the - coil terminal. To my knowledge that will pulse as the points open and close.

 

You do have a 6 volt coil, right?

 

Yes it is, unless they sold me the wrong one. I've also been trying the original coil too, but it acts exactly the same as the new one.

 

Check the wire from the points to the outside of the dist case. Often get broken from the constant vacuum cannister movement. Also the insulating bushing around that stud.

 

Well, if your sure you have at least one good 6 volt coil, maybe a bad condenser? Turn the cap over and check the carbon button in the center of the cap where the rotor makes contact. Also verify you have the correct rotor.

 

Yeah I've replaced all of those wires. And the bushing looked perfect.

 

It's a new condenser. Also new cap and rotor, including the center carbon button.

 

Your checking for spark directly out of the coil? Coil wire pushed all the way in?

 

Maybe the condenser wire is contacting ground? Got to be something simple.

 

A simple test is to remove the wire to the dist and ground it in pulses and check for sparks from the coil.

 

Remove the wire from the distributor side of the coil turn the distributer so that the points are open and continuity of the wire to ground. and check voltage of the distributor side of the coil with the wire off it also should be 6V

 

Not sure I follow.

 

So when I removed the distributor wire from the coil, both terminals now read 6v. So does this mean something is grounding out in the distributor?

 

6v at the coil distributor side is good means the coil is not shorted inside. With the points open touch the distributor wire the coil there should not be a spark. If there is something is grounding out in the distributor.

 

Yes it does.

 

Remove the distributer cap and turn on the ignition and open and close the points manually and see if you get a spark between the points... That should let you know if the coil is okay...

 

"I don't think your (you're) supposed to get full voltage on the negative coil terminal. Check that your points are opening and set at the proper gap. Oh and I think you have a typo in your question."

 

Do you have a ground strap from battery- to the block?

 

Is the distributor turned 180 out? Have you had it out?
You can buy a spark tester which is a bulb that goes between a plug wire and a plug. It will flash if the plug fires. About $5 on eBay.
If you have fuel, fire, and compression, the only thing left is timing.
You might try starting it with a battery charger hooked up. You may have a weak battery. The starter may pull so much current the coil will not fire.
If have jumped 6V systems with 12v for a long time with no troubles. My 241 is 12v with the stock starter.

 

I had that thought, too. But apparently, the engine cranks.

 

I'm sure he has something or it would not turn over. Could try another condenser checking for spark directly out of the coil. Just because parts are new doesn't mean they are good.

 

YES, you have a short somewhere beyond the - (distributor) side of the coil. Could be a shorted condenser, both sets of points not opening concurrently, short where the wire from the coil goes through the side of the distributor, or the wire between the points plate and the terminal on the side of the distributor shorting to the distributor body. Since you said you have " less than a volt on the + coil terminal" (I'm pretty sure you meant to say the - coil terminal) it would confirm that the coil is OK, as if it were open there would be no voltage at all on the - side. I assume your coil is getting warm if you leave the battery hooked up for any length of time.

Please ignore any posts regarding the rotor, cap, plug wires, coil wires, etc. Until you get a pulsing voltage on the - side of the distributor when cranking you will not have any spark anywhere.

 

Are the points opening and closing? meaning simply Do you have the gap set correctly? Single point distributor or dual point?
The points are the switch that causes the primary winding in the coil to build up a magnetic field when they are closed and the circuit is grounded, When they open that magnetic field collapses causing the secondary winding to provide the high voltage that sends the spark to the plug.

The condenser is the shock absorber for the points to keep a spark from jumping the points when they open. Meaning with the cap off and cranking the engine over you should not get a spark across the points. That would mean the condenser was bad.

One thing I have seen in won't start things too many times is that the person who put the point in adjusted them with the rubbing block on the point arm on the flat of the distributor cam rather than the tip of one of the lobes and the points never close but the gap gets wider when the distributor turns.

Red arrow pointing at the rubbing block on the tip of the lobe, blue arrow almost on the gapped points.

Note this is an old six cylinder distributor photo that I took several years ago to use for show and tell for the same thing.

 

I would start by taking the condenser out of the system then each sets of points checking continuity to ground between each part removed

 

Earlier in the thread he said they were opening and gapped at .017". Said it was dual point. Thought we covered the shorted condenser too but there's something he's not seeing. Could it be both point sets are not phased properly effectively making a short? Seems impossible I know. My typing not so good today.

 

Connect a test light to the distributor side of the coil and ground. Crank engine. Does light flash? Points open is it on? Closed, On?