Ok my 75 highboy has a points eliminator in it Pertronix or something similar

It almost starts just about every time by that I mean it starts trying to run the second you let off the key

my thought is it's not getting enough power while cranking so either the starter has excessive amp draw or a bad battery probably battery I'm getting a new one

Any ideas on how to start it in the mean time

 

99.9% of the time, this is caused by a faulty magnetic pick-up coil inside your distributor. So you probably need to replace the "pertronix part".

 

Agreed-whatever replaced the points is bad. If it has a pickup coil, that'd be where I'd start

 

Mine recently did this, I too suspected the pick up coil. when I ohmed it out against another (old one laying around) the were identical. My ignition box is a new one (less than a year old from ford), while testing intermittently voltage at + side of the coil was erratic. So on a whim I changed my ignition switch...hasn't acted up since.......

 

Maybe one of the screws securing Pertronix piece came loose inside the dizzy, and increased the gap between the pickup and whatever it senses, but only by enough to cause the intermittent symptoms?

 

It is literally the moment you quit trying to start it when it attempts to crank finally

 

Does a booster change it any? Sounds like an old 6 volt, not enough juice to crank the starter and feed the coil at the same time.

 

Ohm or Continuity check that pickup, think of it as a coil of wire that picks up on magnetic fields, kinda like a microphone or speaker. Ohms should be really low, and no continuity at all to ground. Might also use the AC Volts measure and see if you can generate a voltage by spinning the distributor.

I doubt it's the pickup or distributor or ignition module.

If it turns over but stops as soon as key is let off, I would say there is something up with the RUN circuit to the ignition module and maybe ignition coil (through the Resistor Wire).

Put a volt meter on the Ignition terminal "+" Pos lead (can check "-" neg too for a sanity check). Voltage at RUN should be around 8 bolts, while at START it should be at battery voltage (pulled downward due to starter motor drain). The Starter Relay/Solenoid "I" terminal supplies full voltage during START. It might be wise to disconnect the starter motor during these tests to prevent being dragged into the machine.

The Ignition Module gets separate power feeds for START and RUN circuits. Both are in that one plug to the main cab harness. Unplug the module to get these voltage readings at START and RUN. This is assuming that an Ignition module came stock with the truck. Since you've mentioned a retro fit, I'm going to assume that the Ignition coil feed is the same operation as above and that it's your ignition module power feeds are the problem. This is where I would concentrate on.

Posting photos would help a bunch also. Hope this helps!

 

I had the exact same thing happen, changed out the ignition module and all was well.

 

I did have an old module that would run until you quit starting it fried the red (or white) wire so it only had power while cranking

 

i have had a simmiler issue with a delco product. Check inside the distributer to see that the fly weights are clean and lubed up. If not you are tring to start with timeing advanced.

 

I'm with captianwoot I have seen a ignition switch fix that symptom a few times, it's a easy diagnosis, with the key on, jump the starter solenoid, if it fires right up it's not a problem in the distributor, or just check the voltage at the coil while cranking with the key.

 

I'm with jackburtonme.... pickup coil! Good luck with it and let us know what you find.

 

OK so it didn't start but it finally tried to run after I switched it to points and got more power to the coil straight off the battery

 

Be careful with that. The coil should only have full 12v while cranking. The rest of the time it should have 7-9ish. Also, the hot to the coil is run thru the ignition module and modulates (on off on off). Always-on can burn the coil up