HELP Ignition igniting frustration

[pontiacgp]

do you still have points and a condenser?

 

[Dayzedandkonfuzed]

Are you using resistor spark plugs? What type of plug wire?

Resistor spark plugs, car came with old accel 8mm that tested ok for resistance, but I had a set of new Belden 8mm wires that fit, less a coil wire so still using the accel coil wire.

Bad coil out of box?

Maybe.

Voltages, what are your voltages? Battery voltage at coil + during cranking. Voltage at coil - should be battery voltage with points open and 0 with points closed.

Voltage at coil + is between 9.5 and 10.3 when cranking, coil - 12.4 points open and 0.6 when closed

do you still have points and a condenser?

Yes, and they're also new.

Obviously not enough voltage while cranking, thought I had this ruled out by running a wire direct from the battery but no difference. Should have just used my voltmeter to begin with, dummy...

I'm gonna add another big ground somewhere and see what happens.

 

[oldsmobile joe]

Voltage at coil + is between 9.5 and 10.3 when cranking, coil - 12.4 points open and 0.6 when closed

I see two problems. Cranking voltage is low. weak battery, poor connections, etc.
and you have too much voltage on the coil - circuit. Coil - circuit should not exceed .2 volts with points closed. Your wasting .4 volts. This can caused by dirty connections, dirty points ( yes, i know they're new, just saying), bad wire, bad coil, etc. Something has too much resistance causing the high voltage. You understand what your doing. Resistance tests are useless at this stage. Try diagnosing using voltage drop tests at places in the circuit.

 

[Dayzedandkonfuzed]

Coil - circuit should not exceed .2 volts with points closed. Your wasting .4 volts. This can caused by dirty connections, dirty points ( yes, i know they're new, just saying), bad wire, bad coil, etc. Something has too much resistance causing the high voltage. You understand what your doing. Resistance tests are useless at this stage. Try diagnosing using voltage drop tests at places in the circuit.

Well I kinda understand what I'm doing lol. I didnt know that .6 was too much on the negative side, and now that you mention it, I do have about a .2 drop across the coil which I thought was odd.

 

[83MonteCarloSS]

Do you know if the stock replacement plugs are supposed to be resistor plugs? High impedance wires and resistor plugs will have a huge affect in your spark energy delivered. Solid core plugs and wires would make a big difference. You can't use solid core with some ignition systems but I would double check what the stock config is supposed to be.

 

[airboatgreg]

Run a temporary 12 volt wire to the coil and see what happens

 

[Dayzedandkonfuzed]

Okay, back on this buggy. I may have found the issue. I also have an intermittent problem with the starter, it sometimes continues to crank when I turn the key back. I believe this will fix both problems, but I can't try til I'm back from work in 2 weeks.

I stumbled across this picture while trying to I.D. the distributor that's in it now. As you can not-so-plainly see, I am missing a ground strap. I've never seen this in a distributor before, but if it's factory, it's probably there for a reason! Will install something when I get home and cross my fingers.