Starting issues with pertronix

[bruceb58]

again...read their instructions, maybe search this forum for past experiences and draw your own conclusion.

Did you happen to read the instructions in the link? It shows how to wire it in with the ballast resistor.

So...did you increase the gap on your plugs or switch to a different style of plug with a bigger gap?

 

[bruceb58]

I do have an accel part # 8140 super stock coil on it

That is a 1.4 ohm coil. You have to use a resistor wire with it. If you had a 3 ohm coil, you could remove the resistor.

If you were measuring 4V at the coil without a resistor wire, you have a resistive connection somewhere causing a massive voltage drop.

 

[VCarris]

Ok no arguing please! You both are giving good info and I will be the ultimate decision maker.... I do not remember seeing anything about the plugs or running different plugs... I have stock wires and checked with pertronix and they said stock are fine as long as they are not solid core...

 

[bruceb58]

Ok no arguing please! You both are giving good info and I will be the ultimate decision maker.... I do not remember seeing anything about the plugs or running different plugs... I have stock wires and checked with pertronix and they said stock are fine as long as they are not solid core...

The reason I mentioned the plugs is that with a higher voltage output coil, you could increase the gap of the plug to take advantage of the higher voltage output of a coil. If you don't change the plug gap, you gain no benefit from a higher voltage output coil.

Call up Pertronix and tell them you have a 1.4 ohm coil and see what they suggest. The stock resistor wire should be 2 ohm.

 

[Benny67]

http://forums.iboats.com/forum/engin...ion-on-m-c-470


Different engine but still same principal...

Bottom line, you need the correct Voltage, Resistance, ect in order for this system to work properly and last long term...you screw around and lower the voltage that's being fed to the circuit, you increase the current and when you increase the current you create heat and heat will shorten the life of that module.

If you read around the internet about the Pertronix setup, you will understand that they recommend installing a 3 ohm coil.

One thing I read I disagree with is the pertronix tech says anything over 9 volts is acceptable...He's a tech on the phone, I am sure if you spoke with an Engineer they would disagree and say it requires 12Vdc and that is what it should be run as because it was designed for a 12Vdc circuit.

For the most part, if you look at that diagram on that older post it's essentially a series circuit that has a fixed resistance value component and coil...they are recommending running this with a 12Vdc input with a 3 ohm coil.

If you vary from this by dropping the voltage via the resistance wire and leave the 1.8 ohm coil in the circuit you will be altering the current in the circuit

If it was my boat...and I just wired both my engines to run on the pertronix (yes, coils as well) I would wire the circuit just the way it is with a new 3 ohm coil in that drawing and confirm the coil feed is 12Vdc when the key is in the on position...in reference to ground...meaning red wire from meter on the + of the coil and the black on common ground. If you can reach it,the negative battery.

Try not to go too far into this problem...meaning,keep it simple and stay within the lines of that circuit, confirm it either works or doesn’t and move on accordingly.

Also,

You might want to call them and see if there is a way to confirm that you didn't fry the module already...see if there's a way to bench test it...it might have been fried in your proccess of hooking it up or hell, it could have been a bad module from the get go..

good luck

 

[Benny67]

Essentially this should have been said at the beginning of this post.

If you want to keep the old coil you would need to pick the 12Vdc up from the feed of that resistance wire.

What bruceb is getting at is with the 2 ohm wire and the 1.8 ohm coil would essentially bring you close to the 3 ohms required for the circuit...that is as long as you tie the red wire into the feed of the resistance wire...that would complete the required resistance for the circuit. In this case, according to the drawing you supplied it would mean that you connect the red to the source of the voltage of wire #20 if that is in fact the resistance wire.

 

[bruceb58]

What bruceb is getting at is with the 2 ohm wire and the 1.8 ohm coil

The Accel coil is 1.4 ohms. That is also what a stock coil is.

 

[Benny67]

Technically any 12Vdc source would do seeing it's all being fed by one single wet cell battery....but to keep it true with the diagram that's where you would go to get your power input to the pertronix module.

 

[southkogs]

Ok no arguing please!

Second that ...

easy does it y'all.

 

[Benny67]

FYI,

You MIGHT be able to wire it up on the bench with a high value (1k5 or so) resistor in series with 12Vdc applied and see if it conducts when the sensor ring passed in front of it.

I would be fearful to use any lower value resistor for fear of causing any damage to the module due to the fact I have no idea what's inside

The value resistance is something I picked out of thin air, based on a current value I would think would be safe to allow to pass through it seeing the conditions it's applied in.

It's basically a "hall effect sensor" it conducts (or not,depending on the sensor) when a magnetic field passes by it's sensor.

 

[Benny67]

https://en.wikipedia.org/wiki/Hall_effect_sensor

 

[bruceb58]

It's only going to conduct for a very short period of time so you wouldn't see it without a scope. The Hall Effect pick up is only used as a trigger to a timing circuit to simulate dwell.

The Pertronix is working fine based on post#19. He just needs to decide if the resistor stays or goes.

 

[Benny67]

It's only going to conduct for a very short period of time so you wouldn't see it without a scope. The Hall Effect pick up is only used as a trigger to a timing circuit to simulate dwell. .

Probably true....your basic meter would not react quickly enough to see.. a scope would be the proper tool to view it with.

 

[bruceb58]

It also looks at pulse to pulse timing to adjust the time it conducts as well since it needs to make the conduction time smaller as RPM goes up.

 

[Benny67]

But it will conduct...just like points closing to complete the circuit via the 12Vdc through the device and coil to create the spark..

 

[Benny67]

It also looks at pulse to pulse timing to adjust the time it conducts as well since it needs to make the conduction time smaller as RPM goes up.

I would think it would need some sort of feedback from the distributor to "look at the time to conduct"

I would think it's just a plain jane circuit that has a built in rpm curve that just has its time to conduct time based on rpm...meaning at XXX rpm I will conduct for xxx secons/milliseconds ect..

 

[Benny67]

Does anybody have an Engineering datasheet for this device? I'd be curious to see it if one exists.

 

[bruceb58]

I would think it's just a plain jane circuit that has a built in rpm curve that just has its time to conduct time based on rpm...meaning at XXX rpm I will conduct for xxx secons/milliseconds ect..

Yep..and it determines the dwell time based on RPM which it calculates by measuring time between pulses. It likely has a small micro-controller inside of it.

 

[bruceb58]

Does anybody have an Engineering datasheet for this device? I'd be curious to see it if one exists.

Pertronix designed it so doubtful.

 

[Benny67]

oh man...integrated circuits have come a long way...it's almost mind blowing in a way.

Does anyone remember in that movie back to the future part 2 when Doc had to create the equivalent circuit for an IC that blew on the time machine out of tubes and an old box that he mounted on the hood?

if you were to do that for this application it would probably be a bigger box...a much bigger box.

okay...enough...now i'm sounding like an idiot.