Engine stalls and restarts immediately

[pschauss]

This is my first season with the boat and I have only had her in the water since last Friday. She has the original Mercruiser 454s. The starboard engine has stalled on me three times. The first time was shortly after I started her when I picked her up at Westin's gas dock in Sayville. At the time, I assumed that it was just because I had not let the engines warm up enough before putting them in gear. The engine restarted immediately when I pushed the starter button. Both engines ran well on my run from Sayville to my slip in Oakdale, about 30 minutes. My tachs showed 2900 to 3000 rpm and the GPS app on my iPhone showed that I was doing about 21-22 knots.

When I had her out again on Sunday the starboard engine cut out briefly and restarted by itself while running at about 3000 rpm. It did it a second time, while I was running at a slow speed up the river to my slip. The engine started immediately when I pushed the starter button.

Any suggestions how I might go about tracking this down?

Thanks,

[PeterPalmieri]

My first suggestion is to rig up a bucket with 5-6 ft of a good strong rope, drill holes in a strong part of the bucket and hang it off the mid ship cleat of the engine that is running. That will keep the boat running straight in the case you can't get that second motor started up. I've run back to Babylon from Sailors Haven and the inlet doing this. I'd also make sure that Sea Tow membership is paid in full.

I chased down a similar issue on my boat for the first two seasons, I'll leave it to the qualified folks to comment on a diagnosis.

[Joseph Fikentscher]

Loose ground? Coil?

[CamB25]

Definitely sounds electrical. My lawn mower was doing this last night...turned out to be a loose spark plug wire. Caveat: the lawn mover does not have a big block chevy engine!

Run at idle, wiggle everything to check for a loose/degraded connection. Be careful around high voltage (spark plug wires). Hopefully you will get it to stall and will be able to isolate the problem this way.

Good Luck!

[pschauss]

Thanks for the suggestions. I will keep a bucket and line handy in case I need to make it back on one engine. (My Sea Tow membership is paid up.) Of course, if one engine stops completely the diagnosis will be much easier.

Based on my experience keeping two old British sports cars (MG and Austin Healey) alive, I was also guessing it was an electrical problem on the primary side of the ignition system. I am going to drive her a bit more to verify that it is consistently the starboard engine. The last two times it happened my daughter and two-year-old grandson were up on the flying bridge with me and things were, understandably, a bit hectic.

[Joseph Fikentscher]

Coils take a little time to heat up sometimes. Then they can fail.

[Carl]

If like mine the Ol-Pull style to turn on ignition switch could be playing with you.

I'd also look at connections around the ignition switch.

...and of course as others have mentioned, all the other ignition parts as its sounding electrical.

[aussierob]

I have a B28 with small block chev's (350).

I had a stalling issue when i first got it. It was spark related due to a mis-wire. It would run fine for hours (such as our maiden voyage - 5hrs at 20kts), then cut out randomly and wouldn't start back up.

My suggestions:

1. If you have a low voltage coil for use with a resistor (don't know if they have these for 454, but common on old 350s), check if the resistor is getting hot. Some use resistor wire instead of a ceramic block. If this wire gets too hot it'll shut off the motor too.

2. Check the distributor cap and rotor for wear. However it doesn't sound like a distributor issue.

If i were hunting for the problem myself, I would think it's a coil or bad wiring to the coil. An easy test is to swap the coils over and see if the problem moves.

However it's the "restarted by itself" that has me thinking....
I've had engines stall randomly due to a bad fuel pump (had a 60mile steam back on one engine and 8kts as a result).
But you usually see erratic RPM and it's not a clean stall as fuel pressure fluctuates - but it depends how it fails.
Electric fuel pump can have a clean fail - especially if the oil pressure safety switch connection intermittently fails.
Also check the fuel lines for water, and if the filters haven't been replaced recently, do so.

This is one reason i love having two engines!
My 2c.

Rob

[pschauss]

Whatever the problem was it has not recurred since my original post. I installed new engine hour meters last weekend to replace the nonfunctioning existing ones. I have put about 3 hours on the engines since then.

I guess it is conceivable that intermittent short in one of them might have been causing the miss.
I have my fingers crossed.

[Rawleigh]

If it reoccurs, try switching the coils from one side to the other and see if the problem follows it. That is one big advantage to having twins!

[pschauss]

I actually was about ready to go after the coil but I wanted to collect some data to make sure I knew which engine was stalling and how long I had been running when it stalled. Of course once you start watching, it doesn't do it again.

[White Bear]

From my limited experience, coil failure is usually temperature related and does not allow an immediate restart until it has cooled. If it were mine, I'd turn on the starboard engine, don a pair of gloves and start shaking wires looking for a loose connection. Thinking about it, there are only a limited number of wires that comprise an ignition circuit so it really shouldn't be that difficult to check. Bad ignition switch and ballast resistor (if you have one) are also possibilities.

[ccroke13]

Hey there, just reading this now and not sure if you got your problem figured out yet. I just had the same issue and it ended up being a bad ignition switch. On the back of the switch one of the posts were broken. Replaced switch and all was good.

[pschauss]

Thanks for all of the suggestions. I have not had the stalling problem since I replaced my nonworking hour meters about four weeks ago. I have put about six hours on the boat since then including two round trips across the bay (Oakdale to Sailors Haven and Watch Hill).

[pschauss]

My port engine has done this twice in the past week. Friday, I took the grandchildren out for a short ride in the bay, running at about 2500 rpm. Running out from Oakdale to buoy #28 (about 10 minutes to get out of the "No Wake" zone and 7 minutes running at 2500), the port engine stalled. After restarting it would run at 2500 for a few minutes and then stall again. After three or four repeats of this process it ran fine all the way back to my slip.

Today I took a test run by myself from Oakdale to Sailors Haven. At about the same place in the bay, the port engine stalled. This time I only had to restart twice and I was able to run all the way across the bay and back without having the engine stall again. When the engine stalled this time I opened the cover and verified that the coil was not hot. Engine operating temperature was within the expected range, around 150-160.

My experience with my MG has been that when something is going wrong in the primary ignition circuit the tach starts to jump around. I have not seen that in these situations. Also, the voltmeter, which is wired to the ignition switch, continued to show battery voltage throughout the incident.

What else should I check the next time this happens?

[Tony Meola]

Could be the Carbr fuel pump. Is the choke open or is it closing on you when it stalls?

[pschauss]

Is that like the accelerator pump on a car? The choke seems to be opening properly when the engine warms up but I will check it the next time it stalls. The site glass on the fuel pump is dry.

[lobsta1]

It might be heat related. Pick up a can of duster at Staples & try spraying the distributor next time it happens. That should cool it down. Suggest you wear a rubber glove when you do it.
Al
P.S. read the can label & make sure it does not use butane as a propellant.

[Tony Meola]

Peter

I should have sauud carbs or fuel pump. Sounds like a choke or the carb is running dry for some reason.

That could be great related, may be a vapor lock of some kind.

Check the floats in the carb.

[MikeD@Lightningshack]

Perplexing stuff!

You need to narrow down whether it is an electrical or a fuel problem.

At next stall I'd leave the key in and on, and I would go check the coil for 12 volts. If it has better than 12 volts, at least you know the coil has power. If it doesn't have voltage something maybe wrong with ignition switches or the wiring to both switches.

I'd then use a timing light to see if she is creating ignition sparks. You can put it right on the coil wire on the distributor, turn the engine with starter, and if it lights up you have spark.

If you are lucky you'll find an electrical issue. If not it, it could still be an intermitent electrical issue.

The fact that 2 engines are now experiencing the same issue has me leaning toward a fuel problem.

Many things you wrote make me think something else is going on, but be aware that the carbs have a small screen filter in the fuel port. I have seen these filters or mesh screens clog up and cause boats to lose power or stall. Unlikely that this is part of the issue because it starts back up, but I guess you can't rule anything out yet. Might be worth checking those screens if you cannot find an eletrical issue.

In my experience coils are often all or nothing. So I thiink it is always a good idea to carry a spare coil onboard. However, because it comes right back to life, I'm not thinking it is a failing coil, but intermitent coil power could shut you down.

Hope this helps you narrow it down.

Mike

[Pete Fallon]

Check the ignition switches and the push button start switches, check for loose ground wires and the the voltage regulators if you have them also if you have ballast resistors check them.they over heat when old. Is it just the port engine or both motors, could be a bad fuel pump,
Pete Fallon

[pschauss]

Pete,

As of right now it's just the port engine. The problem that I had with the starboard engine was that it cut out and would not restart until the ignition components had cooled down. That engine has been running fine since I installed the proper 12 volt coil.

A while back, I posted a question about a Perko inline fuel filter (http://bertram31.com/newbb/viewtopic.php?f=2&t=14225). This filter is in the fuel line for the port engine, fastened just inboard of the main frame member about even with the steps. There is no filter in it. I am wondering if it is contributing to the stalling problem.

[Pete Fallon]

About the old Perko fuel filter, I would replace that entire fuel line starting at the shut off on the tank all the way to the carb. I had those filters in my 1961 express they had 2 ceramic bowls inside the housing. Your fuel line looks like it's time for replacing, getting old and dried out looking. Make sure you put in USCG approved fuel hose that is resistant to ethanol/ alcohol, type A-1 hose. Your stalling problem could be a bad fuel pump or even vapor lock, lots of heat builds up in 31's engine boxes.
Pete Fallon

[pschauss]

What size fuel line should I be using?

[ljmauricio]

Had the same problem. Bad ignition switch. Reversed them, and the other engine did the same thing.

[pschauss]

I ran a new fuel line (A1-15) from the tank to the cutoff valve at the engine and removed the old Perko filter. When I removed the old fuel line I discovered that whoever had installed it had looped it down toward the bilge because it was about a foot and a half too long. I took a short test run today but I still need to test a bit more to see if I have fixed the problem.

[pschauss]

On my last test run my port engine stalled several times, once at 2500 rpm and a few times at idle speed under load. It’s hard to hear the engines from the flying bridge (and dangerous to drive in the Connetquot River from the lower helm), but I thought I heard the alternator belt slipping just as the motor stalled.

If the alternator is seizing up would that be enough to stall the engine?

[Mack]

Had something similar with one of my 454’s cutting out earlier this year. Everyone said electrical but it ended up being a weak fuel pump.

Change your fuel filters to assure it is not a restricted flow issue. Swap the coils with the “working” motor to see if it is in fact electrical. If that doesn’t work, disconnect the fuel line from your cab and check the fuel flow when you crank over the motor. That is how we figured it out. Weak flow. Fuel pump has been replaced and no issues since!

Good luck

[pschauss]

I replaced the fuel pump today. Hoping to bay test it this weekend or early next week.

My engines actuate the fuel pump with a pushrod slides up at an angle into the block where it rides on the camshaft. Getting this rod to stay out of the way while I lined up the pump and bolted is was a challenge until the guy at my marina told me to clean the pushrod thoroughly and then grease it. I assume that the grease helps to seal the hole in the bock so that the vacuum keeps the pushrod from sliding out.

[Tony Meola]

I replaced the fuel pump today. Hoping to bay test it this weekend or early next week.

My engines actuate the fuel pump with a pushrod slides up at an angle into the block where it rides on the camshaft. Getting this rod to stay out of the way while I lined up the pump and bolted is was a challenge until the guy at my marina told me to clean the pushrod thoroughly and then grease it. I assume that the grease helps to seal the hole in the bock so that the vacuum keeps the pushrod from sliding out.

Peter

Be careful inserting that rod. If it is not right you will bend it. My father could install these in his sleep and he showed me how to do it, but my cousin and I, who have both done this before without a problem, managed to ruin one. If my father had still been alive he would have had a few choice words for us.

[pschauss]

Tony,

It's hard for me to see how you could bend that pushrod. If the lever on the pump does not slide under the end of the rod, the pump will not mount flush to the block. I was lucky that this was on the port engine where I could work from the companionway.

[Tony Meola]

On those old big blocks (not sure if it has changed) if you did not line it up correctly, it would bend when you tried to start the engine.

[pschauss]

The pushrod on mine is a 1/2” diameter steel rod about 6 or7” long. It would take a good bit of force to bend it. Apparently I got mine reassembled correctly because it started without any extra noises when I finished.

A short test run in the bay yesterday, however, showed that I still have the stalling problem so I am back to square one on that.

The good news is that my fuel gauge is working now. One less item on my list of minor repairs to complete.

[Carl]

Thick grease acts like glue holding rod up in place till you mount the pump.

Works well for holding o-rings, washers, screws,shims etc.

[pschauss]

I replaced the electronic ignition module in the Prestolite distributor with the part that Sierra lists for it. I took a ride from my marina in Oakdale to the number 28 bouy and back. The port engine did not stall. So far so good.

[Tony Meola]

Peter good to hear. You sure have been chasing gremlins. Hopefully you solved the problem.

[pschauss]

Thanks. You guys have been really helpful.