351 W stops after being shut off wont start

The base in the distributor is gone. So the chance of a retro fit would cost me a whole new distributor.

Thanks

Commodore Bob

Thanks,

Did the new Distributor just drop in or would you suggest professional install. Do you have the part #. The ones I see on the net have a vacuum advance?

Commodore Bob

The distributor I dropped in had Vacuum advance but we did not hook it up. It has no advantage in a boat because the engines are under load all the time. In a car it really helps but not in a boat.. Before ordering any distributor make sure you check your clearances.
The one we installed barely had room. The Ford is pretty tight for space.

In my old boat i converted to pertronix ignitors. worked beautifully.   Because it was an offshore boat and we typically traveled over 35miles out i carried 2 spares but never had an issue during the 6 years we ran it.   only thing that happened was the coil on starboard engine came apart, end shot out, screw was loose and oil leaked out.   That was a pertronix flame thrower coil. after that i pulled coil on other engine and tightened up the screw before it became an issue.   

shierh wrote: In my old boat i converted to pertronix ignitors.

I'm always curious about why? Dwell a problem?

Did you confirm loss of spark when this happens? I did not see that.

phillipsrj wrote: Confirmed. I pulled a plug and no spark. Commodore Bob

No spark but why?
You didn't follow my instructions did you!!!

8122pbrainard wrote: Pull the main center wire off the distributor. Put a spark plug in the end keeping the other end in the coil. Ground the plug to the block. Remove the negative wire from the distributor off the coil. Turn on the ignition. Using a jumper wire from a block ground, ground the negative side of the coil briefly. When the ground is removed from the coil, you should get a spark. . If so, it's the junk EI conversion.

phillipsrj wrote: I think I have it narrowed down. It is ignition. The Coil gets very hot and shuts down until it cools off. I do not know what is causing it? I am replacing the ballast resistor today thinking it may be the problem? Commodore Bob

Bob, you are just throwing parts at it without doing any testing!! As HW and I suggested, FIND HELP!!!

Now you are telling me that after it starts and runs perfectly that the plug gap is the problem?

Commodore Bob

I just went through all of this so I thought I would chime in with some info that I learned.

Go to the manufacturer of the electronic ignition and read the specs on their module.

These units are made for cars and you have to get a couple of things right for them to work on a boat. I had the same problem. After running the boat for a short time the coil would be stupid hot, start to miss and then fail. Burned through 2 coils. This is what fixed my problem.

I am running a 302 with converted distro.

I have a pertronix 1581 kit on my Prestolite distro so I will be referencing that. Most kits say to remove the ballast resistor to the coil.   What a ballast resistor does is drop the standard 12 volts in a car down to about 9 volts that coils and points like to run at. The new style coils for electronic modules all run at 12 volts. No problem in a car where it is easy to find a regulated 12 volt line.

On my boat the alternator puts out a solid 14.4 volts when running. This put my amp draw at 9.8 way too high. So I needed a ballast resistor to bring this down to 12 volts. Pertronix says the module can pull no more than 8 amps, so Ohms Law. 14.4/8=1.8 I needed a 1.8 ohm ballast resistor to be within spec.

So alright you want to buy a ballast resistor, but they don't sell them by ohms they sell them by car model. I found a 1.4 online. And used a coil with internal restance to get what I needed.

Pertronix says the coil and module circuit must have a minimum of 1.5 ohms of resistance to function properly so I used a 1.5 ohm internal resistance oil filled flamethrower coil and all should have been good. Running at about 8 amp draw.

It burned up.

On my engine the coil is mounted on its side. You can't mount the new oil filled coils on their side they don't like it. As soon as I started talking to the hot rod guys they all told me this.

So I bought an epoxy coil with a higher internal resistance, 3 ohms. 12 volts / 3 ohms =4 amps of current that the igniton module draws. I have run the HELL out of this set up and it has been rock solid,

If I want a little hotter spark, I could remove the ballast resistor. 14.4 volts / 3 ohms=4.8 amp draw and a hotter spark.

Worked for me, YMMV.

I have exactly the same problem. Mid 80's 351 W transplant in a '72 Martinique. Holley carb. Starts fine cold with one pump of the throttle and runs great. It also needs to idle a bit high. Initially replaced a non- functioning choke thermostat and replaced solenoid. Still have the no re start issue when hot.

Yes, epoxy doesn't matter how it's mounted.. But then again neither does the OEM oil filled coil, when came sideways on the engine. I think the aftermarket coils are orientation sensitive.

Is your coil hot when the problem appears? Could just be a ballast resister issue.

I would test the coil when you see the symptom before spending money.      You could use an ohmmeter or just manually trigger a spark (described above) to see if coil is the cause.

The coil works when it is cold but when it is hot it does not. I found that one of the poles of the ballast resistor was broken ( when installed it was turned too far and broke the connection to the resistor, not very noticeable unless you removed it) and I am in the process of replacing it. This could be the Hot coil problem?

Thanks much for all the help!

Commodore Bob

Because I was told about the Ballast resistor that I would have never known about. The OLM load of the coil that I had was too high 6 instead of 3 and the oil filled coil instead of an epoxy filled coil.
Thank you all

Commodore Bob

Thank you for the welcome. And the thoughts. Diagnostic time is slim with the weather turning. She is close to going into winter storage. I've been attempting to post pics. Will get some up soon.

Here are a couple of pics of my '72 Martinique. She's new to me this summer and I haven't had time to get to know her.   Two days ago, with my hot start issue, I immediately raised the engine cover and removed the flame arrester for cooling. In 5 minutes, 10 tops, she fired with one throttle pump on the Holley. Now thinking that heat needs to be removed from the engine compartment. Realized that the blower should be doing this but found no intake hose connected to the blower. Put one on today and took it straight to the engine compartment. Unfortunately she is out of the water now but I'm anxious to see if this helps/ cures the no hot start.