Trouble on ignition street

Check the grounding of the EI inside the dizzy. If that is good then the EI isn't. Time for a mallory E spark kit, or new dizzy, I think.

FYI, that is a Prestolite EI kit. PCM branded it as their own for a while. I believe it requires that you bypass the ballast resistor... but that may already be the case if youre getting +12v at the + side of the coil.

Gary S wrote: I know on a points distributor that it needs to be grounded,not sure about those. But you did paint that engine all pretty,maybe you need to clean those grounds up.

Is there a wire on the points that goes to a ground? I only have 2 wires coming from the distributor and they both go to the coil (Purple to the + side and black to the - side). There are no wire connections inside the distributor that is what lead me to believe it grounds through the mount.

I did sand the block to bare metal when I connected my battery ground. I did the same to the engine harness where it connects to the intake at the back of the engine. I will double check those tonight and put a little dielectric grease on them. I don't think I did that when I connected them before.

Big Pappa wrote: Gary S wrote: I know on a points distributor that it needs to be grounded,not sure about those. But you did paint that engine all pretty,maybe you need to clean those grounds up. Is there a wire on the points that goes to a ground? I only have 2 wires coming from the distributor and they both go to the coil (Purple to the + side and black to the - side). There are no wire connections inside the coil that is what lead me to believe it grounds through the mount.

Nope. The module needs 12v to operate (purple wire), and its easiest to steal it from the + side of the coil. The black wire is the same as a points dizzy- its the trigger that tells the coil when to fire its primary voltage (through the cap/rotor and to the plugs). Youre hooked up correctly.

Weak/intermittent spark makes sense if youre currently running the module through the ballast resistor (assuming its not supposed to). Might want to call SkiDIM to see if they recommend bypassing it (connecting all wires to a single post). My bet is that they will. Thats how my Prestolite EI kit was set up for the short time I ran it.

Then its already bypassed.

mark c wrote: Electronic ignitions do not require a ballast resistor

You'll want to be careful with a blanket statement like that. Certain EI conversions (or full up distributors) still require the use of the ballast. I believe the Mallory optically triggered modules (Unilite) fall into this category.

Its best to follow the instructions that come with your individual kit.

When the contact points are closed the primary winding of the ignition is connected in series with the battery and carries an electrical current of about 4 amps. Since the points are shorting across the capacitor, the capacitor does nothing at that time. The core of the transformer is an electromagnet with magnetic field induced by the current flowing in the primary winding.

When the points open to break the ground contact the primary current must stop flowing, and the magnetic field in the transformer will collapse. The collapsing magnetic field forces current to continue flowing in the same direction momentarily, and that current will charge up the capacitor. Forward inertia of this forced current raises voltage at the capacitor momentarily to about 300 volts, at which time this high voltage stops the current. The current then reverses direction, being driven backward by the high voltage at the capacitor. After the charge in the capacitor is depleted, inertia of the current in the transformer continues to drive the current in that direction to charge the capacitor in opposite polarity. The cycle then reverses. The result is an electrical ringing like a bell which reduces rapidly with time.

The initial 300 volt spike in the primary winding will drive an output in the secondary winding up to 30,000 volts. The output current going to the spark plug will likewise ring in harmony with the input current, for as long as the output voltage is high enough for current to jump the spark gap under compression. Assuming the initial spark ignites the fuel air mixture, combustion pressure will rise rapidly, and the spark will stop almost immediately as voltage falls.

But none of this deals directly with the electronics that control the "contacts" in a magnetic point set. This part of the system either needs 12 Volts to operate, or like was said before will operate under the same 9 or 10V circuit that ulimately powers the coil. The older cars that used resistor wires had a bypass wire connected to the starter coil that provided full battery voltage to the coil during cranking to ensure there was sufficient voltage (an current) to the coil to fire the engine during starting. Also the original coils that used external ballast resistors had a lower primary coil resistance down in th 2 ohm range. Depending on what coil you had, and what was replaced you may now have a higher internal resistance coil, further limiting your primary circuit current flow, and hence your spark energy. Make sure the coil you just installed is the correct one, if you have a meter, measure the resistance from + to - on each of them and make sure they are not radically different.

How does you capacitor look, is it bulging anywhere, and does it have a good ground connection, because thats a good place to start looking when you have a weak or inconsistant spark. I had a condenser break off (rotor wire sawed right thru the lead wire) and the engine would start fine because the circuit was getting the higher voltage thru the bypass circuit but would not run once the key was released. Took a while to find that problem.

The magnetic pickup is now your points, the contacts are just being opened, closed and timed electronically instead of mechanically. The system still works the same way, theres just less wear induced failures.

You have to have a condesnor somewhere. It may be built into your electronic module (I don't know yours specifically) but the system won't work without one.

Gary S wrote: Kris the distributor just grounds thru the clamp. My Dad had a PCM powered center console that started going thru condencers. Being a center console you could not see in very good so finally he pulled the distributor and found the clamp and block rusting.Cleaned it up and did not have any trouble again. Just a thought.

Good to know and it is very possible that that could be rusty. I will give that a good cleaning and see what happens.

Not all but some do, all older cars do. Like my 69 Camaro. Probably started to go away when GM introduced the HEI, 1974 or 75 maybe. Its not a bad thing to have if you've got an engine that is hard to start. you just run a 12 or 14 gauge wire from the starter relay straight to the + side of the coil, then whenever the boat is being cranked you get full voltage to the coil, and a more powerfull spark. GM engines can get the 12v from the aux contact on the starter solenoid, fords and chryslers are going to have to pull it off the starter relay since they don't have an integral starter solenoid with the extra contacts on them specifically for this purpose.

I have been in and around boats since 1958, made my first trip in my grandfathers pacemaker when I was two weeks old. From then until I joined the navy he (USCGA Commander) went thru another half dozen Pacemakers, and Chris Crafts, in the 32 to 36' range. My own boats were almost entirely outboards, from 8 footers with a 3HP Johnson, up to my last boat a 93 mph 17' Hydrostream Viking with a 235HP Johnson, and everything in between, wood, fiberglass aluminum, if it could float we would figure a way to put to big an engine on it. Now I'm working on bringing that nasty 87 BFN I bought a couple of weeks ago back to life.

see my edited reply above

mark c wrote: see my edited reply above

Mark,
Sorry but I didn't remember! Plus, I should have gone back and checked your previous posts.

Yes, how are you doing on the BFN? The only picture I could find was in this thread where you were asking about the colors.

Kris - You can get a replacement module if you want to stay with this dizzy:

Module

PS here is a tip from that site-
Most non-spark issues are a result of improper air gap between trigger wheel "teeth" (high point of trigger wheel) and the face of the sensor (pick up), gap must be between .008" to .010", use a non-magnetic feeler gauge. Tighten the sensor retaining screw to 3 to 5 inch pounds of torque.

Big Pappa wrote: So is it sounding like mallory E spark time or is there anything else to try?

Your module is toast, if you replace with a Mallory E Spark , the ballast and solenoid will be used. Normal run voltage at coil is 9/10 volts, while crank voltage , thru the solenoid will increase to a full 12 volts at the coil for crank only.

CorrectCraftParts{ 318-299-8547} has a Mallory conversion for you Prestolite.