Dreaded 2 Engine failure

[Svend]

I was out boating yesterday in my 1977 F30 Express, dual 318 chyrslers with chrysler electronic ignition when both engine suddenly died! (an of course, I was in a small, very narrow channel with lots of boat traffic!! lol)

The engines would turn over and act like they wanted to start, but no go.
A tech looked at it and thought it was an ignition issue... a kill switch (there is not one), etc...
It turned out, we got them stated again after hitting the RED reset button on the electronic ignition (or I think that is what did it...)

the tech tried running a wire from positive on battery to ignition coil... this did not seem to work as he thought it would.
the tech was able to short a couple leads on ignition switch at helm, and this started it, but could not be kept like that...
then he pushed on electronic ignition reset real hard, and that seemed to fix it?!
in all the rush and madness of the moment, can't be sure...

one question to you all, is why did BOTH engines quit at the same time?
why did reset on one electronic ignition fix both motors, since there are 2 electronic ignition system, 1 on each motor
I would like to think each motor is totally separate and one issue with one motor will not bring down the other

any and all thoughts would be most welcome. The motors have worked every day for 30 days since i bought this old classic without a hickup

thanks!

Svend

[P-Dogg]

A friends boat died under similar circumstances once. Months later he figured out that the automatic CO2 fire extinguishing had failed, starving the engine of O2......

[Svend]

That is a most interesting idea... but my issue was related to ignition issues, and the 318 Electronic ignition.

Can you explain how the fire extinguisher supplies O2 to the engine...
My fire extinguisher is from 1977... not sure it could supply that much O2...

thanks

any others have experience with the 318 Electronic ignition, and how it can cause 2 engines to fail at the very same instant...

Svend

[prowlersfish]

That is a circuit breaker that "popped" . Since both engines died I would think someone has rewired it so both ignition switches are pulling power thought the one side . If this is the case it needs rewired

[Svend]

that is a great idea...
I think you are right... and will have wing checked out...

whoever owned my boat before did a pretty crazy setup with the starter batteries and house batteries...

on my boat, I need to have boat battery switch in BOTH position for engines to start. I cannot think how this would be normal?! any thoughts.

Svend

[captainmaniac]

In theory both electrical systems should be isolated, but having said that -- who knows what previous owners might have changed in the wiring over the past almost 40 years! If you have a wiring diagram (you might also have one stuck to the inside of the big plastic cover over the electronic ignition components), see if you can do a quick compare between what it says and if you can spot any cross-engine or cross-battery cabling that shouldn't be there.

I did find one 'crossover' point a few years ago, but unlikely it is contributing to your problem... the engine synch gauge (assuming you have one of the originals) takes signals from both distributors, hence is a 'bridge' between both electrical systems. Original wiring of it also did not include any in line fusing, so there is potential for a voltage or current spike to move from engine to the other through it. That would tend to fry the synchronizer though.

EDIT : OOPS - looks like Paul posted while I was thinking / typing. Same idea though.

[Svend]

Interesting about ENGINE SYNC GUAGE.
I find the way i use boat... it is not required... 99% of the time, engines are running at same RPM...
so i think they could be removed?! Any thoughts on that?

I do like the idea of keeping both engines totally apart from each other... so if one fails, there is NO tie or connection to the other...
any thoughts on that?!

thanks!! great ideas here...

Svend

[g36]

If your sync gauge is working why remove it? They are nice to have but most everyone can learn to hear when the engines are out of aync. I wouldn't make the assumption that because your analog tach reads the same that they are sync up they may be close but you could then see with your guage or hear it to correct them

[Scorpion07]

Remove the synchronizer!
It may not be the issue, but it can contribute.
I chased a stalling engine for four long years. If it wasn't one it was the other. Sometimes both. Sometimes no issues. But both motors were always linked.
Replaced ignitions, coils, wiring, alternators, charger. Even carbs thinking I was misdiagnosing electrical. Rewired my battery system. Removed emergency start switch. On and on.
One day when in the helm I decided to remove the synchronizer from the circuit and.....just like that, problem solved!!
She runs perfect now. And should....all new stuff!

[Scorpion07]

Oh yeah.....the synchronizer worked before I removed it.
It was the hooded strobe light type.
Both engines are completely independent now as well.

[Svend]

that is great info!! my local boat guy said it was not needed...
use RPM and ears he said and get rid of a potential problem!

thanks!!!

btw... how do you remove synchronizer?

Svend