team Tickfaw

I ned some help here guys. Took the boat out and ran several hours without a problem. Upon the return trip to marina ran it up on the stops (4700/4800 rpm) for about 5 minutes everything looking good as far as temps, oil pressure etc. Then the port engine just quit's, like you just shut the key off.
I go to recrank and the starter (I think) making a loud grinding noise. So I don't try anymore. Limp on in on one engine. Think that the starter was going south the last few times I ran boat because it sounded a little noisy and maybe by co-incidence it went for good this last outing. It is a small high tourqe gear reduction type. Starter does turn engine over but noise is loud and sounds like its chewing something up so I have only bumped it over a few times. So I have a starter coming.
On the engine shut down issue I have attempted to trouble shoot somewhat. I have pulled distributor cap off and verified that rotor turns thinking that a drive gear sheared. Checked for spark at coil and compared with other engine. It does appear weaker. Cap has 1/16 inch long white deposites on the end of each contact. Rotor looks good. Coil is 2 yrs old. Engine has 150 hours. No water in oil. Replaced battery.
Checked all electrical connections. Have fuel pressure and opening butterflies on carb does squirt fuel.
I am wanting any advice to troubleshoot. I was told to check the coil for proper spark but do not know how to do without using the starter and for obvious reasons cannot do that. I was told there is a way.
How can I check the pickup inside distributor? What about checking control module?? Will a weak spark shut engine down?? Note when I checked for spark it was about an hour after engine had been shut down. Possibly coil broke down during high speed run and after cooling down for an hour started to "come back to life" giving a weak spark?? Engines are '89 454's.
Sorry for all the questions but everyone has been a big help before on such matters.

niceguy

a coil either works or it doesn't.

As funny as it sounds, check the oil level. I had this happen to me once and that seemed to be the issue.

hoozeyurdaddy

coils will breakdown when hot and after cooling start to work again, but shortly after that they will die completly, after you get your starteer, fire it up, if you can, could the lanyard switch have activated? check the ohm's between the coils and compare with the one that runs, positive to negitive and positive to spark tower, if it still won't start switch the ignition mod's.

team Tickfaw

That is the route I am headed in right now. I checked the lanyard switch and when I pull them it shuts all power off to ignition switch, will not turn over or anything.
Never heard of a high oil level causing a shut down. Did check oil and it may be a 1/2 quart high.
Thanks for the input. Anyone else got suggestions on this and how to check components?

hillbilly24

The ignition module in the distributor would be the first thing I would look at once you get it cranking again. They will also produce the same symptom of shutting down when hot then coming back to life after cooling off, but again just like the coil it will take a complete dump soon. It is easy enough to swap for the other distributor to verify, the little screws can get pretty corroded and be a pain sometime but other then that it is simple. Make sure you use the heat sink compound that comes with the new one if it turns out to be the problem.

team Tickfaw

Thanks all,
So far I have replaced coil, checked amplifier. On my wat now to pick up a sensor / moduel for the distributor. Had mechanic listen to engine as I bumped over it said the starter gone. Will change that out friday. Hopefully on water saturday.
Will keep posted on what was found and the fix. Will verify how we checked the fire of coil and amplifier and post.
Thanks

blue thunder

If it shut off at speed I would guess an exhaust valve issue which in turn caused water injestion. Then the starter was unable to compress the water in the cylinders and now that is toast. Hope not but that is where I'd be looking. Pull the plugs and look for water. Also it might turn over fine with the plugs out.

BT

team Tickfaw

Blue thunder, I had not thought about that. I hope that is not the case. I put a breaker bar on it though and turned engine over and compared it to other engine. Seemed the same effort was used. Did not pull the plugs. Will do tommorrow. If that was the case would there be water in all? Or pulling any plug will do? If this was case would I see water in oil?
Changed moduel in distributor. Looked very rusty.
Thanks

blue thunder

You need to pull all the plugs and look for water on each. A compression test would tell you if you have a valve issue. If all that checks out good and the new starter cranks the engine, then proceed to the ignition. FWIW I one time had the purple ignition wire short out between the cannon plug and the alternator, stock 1988 mag engine. That was a hard one to find but the symptom was more intermittant than yours. Fix/verify your mechanicals first then you can start fact finding again.

Boat Tech

Here is a link to test the sensors and coil see post #2.http://forums.iboats.com/showthread.php?t=320755