Electronic Ignition Coil voltage

I have a #609 Mallory electronic ignition conversion. Mallory paperwork shows that the voltage to the coil with key on should be 6V. I have two .8ohm resistors installed but am still showing 11.5V at the coil. Boat get hot after running 15 min. and then starts to miss fire and dies. Then will not start. I have a new Mallory blaster Coil PN 8222. I do not see how 6V at the coil can be right?? Any thoughts.

The distributor is SAE J1171 (this is what is on the label), marine distributor which was installed by the Nautique dealer. The magnetic module is the P/N 609. I am not sure what the original coil was, it was replaced by a mechanic I had work on it last fall. I have replaced the coil with Blaster 8333, the the non-oil type designed to sit horizontal which was recommended by Mallory tech. My boat is a 1989 Nautique with 351Ford engine. My problem is that as soon as the engine warms up it begins to misfire and dies, then will not even try to start (Fire). It will turn over strong. Originally the boat had one resistor in line, Mallory tech said I should add a resistor (Making two total) which I did and it made no difference. I have a new Holley carburetor as well. I replaced it thinking I might had a fuel issue. When it is not starting I do have gas going into the carb, and if I pull a plug I can see I am getting some fire to the plug, but I really do not know if the spark if strong enough, no way to tell that. As soon as the engine cools down it will start right up and sound great. When it is not starting I can jumper across the resistor and it will start right away. I tried leaving the jumper on the resistor but after it ran a few minutes it started to misfire again and died and then would not start.
I have a new 609 module but am afraid to replace the old one till I know more about it. If I am getting too much voltage to the coil I do not want to damage the new expensive module.

I purchased the resistor form Mallory, which was the same as the one that was already on the boat. Both are .8ohm. 12V going into the first resistor from the ignition relay, then out to the 2nd relay, then out to the coil. Coil then to the module.
voltage at the ignition relay is 12.5V.

If your coil needs a resistor, you should have the resistor between the ignition switch and the coil. Some Ford designs also use the "I" terminal on the starter solenoid switch. The "I" terminal wire goes directly to the coil and bypasses the resistor. This is because the starter takes up so much "juice" that the resistor would drop the voltage too low. The "I" terminal is only energized during engine cranking, giving 12V to the coil. After the engine starts and the ignition switch is in the "run" position, the "I" terminal is not energized and the coil is fed from the ballast resistor.

Put a volt-meter on the before and after side of the resistor. You should be getting 12+ volts coming in and 8 to 9 volts coming out.

I may be totally screwed up...KENO will help tweak any bad information.

JQ

If I was me, I'd wire it like the diagram in the link at the bottom

It looks like you have the same distributor (Mallory MBI) as the retro fit kit for the Protech system.

Wired like that you'll have alternator voltage to the Module. About 13.5 to 14 volts and reduced voltage to the coil (about 2.5 to 3 volts less).

I'd use a 1.5 ohm coil run of the mill coil that says "external resistor required"and a 1.3 ohm resistor.

A couple of part numbers would be coil BWD E70 and resistor Echlin ICR23 or stuff that cross references with them.

You really don't need that extra relay that you mentioned either.

And make sure the ground wire is cleanly and tightly grounded to the block

No guarantees but I've got a friend whose boat is wired like this with the same Mallory MBI distributor and it's had no issues with cooked modules or fried coils etc with lots of hours on the setup.

It's also got the wire that JQ mentioned running from the "I" terminal on the solenoid to the coil positive to provide maximum unresisted voltage when starting the engine and as soon as you go back to RUN on the key that power is removed and power is from the resistor output since the "I" terminal only has power in the START position of the key.

It's hard to say if your module may be the issue, but I'd wire it as described and if the issue is still there, you may have to get brave and put in the new module "for testing"


link