Request advice with stalling engine

[Jon K]

Thanks in advance for your advice.

My 1985 Atomic 4 has developed some problems, it stalls after reaching 180 degrees and won't restart until it cools. It also has a history of performing fine under power, then stalling when brought to idle when returning to port.

History:

I bought a late 1970s Ranger 28 in 2006, the marine surveyor said it was sound and we began sailing the boat and updating the cabin.

Recently I have noticed that the wiring in this negative-ground system uses different colors of wire, spliced partway through each run to another color. With red, orange, white and yellow wires, the only color absent on the ground side is black. I've added a second cigarette lighter receptacle so the GPS and handheld spotlight can be run at the same time, not much else.

I read about the Atomic 4 and learned how to do a few things, including how to change the oil. It is a traditional, un-upgraded engine with a new heat exchanger - freshwater cooling and two pumps. It burns a little oil, perhaps a quarter-litre per season of 10-12 hours of use. I tend to run the engine near or at top RPM, using my ear to avoid over-throttling. After 5 seasons I have put about 70 hours on the engine.

At one point the engine was overheating, it turns out that the saltwater through-hull was clogged with seaweed. A coathanger was an easy tool to clear the clog. Now it runs at 180 degrees all the time.

Every season we make a long trip that begins with a 5-hour crossing of the Georgia Straight between the mainland and the Gulf Islands, here in the Vancouver, BC area.

In the fourth year, returning from one such trip, the engine stalled after a few hours, when brought to idle from 2-3 hours at full speed. We had slowed to make a passage between two islands, possible only at flat water. Luckily a passing motorboat offered us a tow through, and we decided to make port nearby to diagnose the problem. As it turned out, during the passage the problem had cleared and we were able to restart and continue home.

After a speedy 3.5 hour crossing under sail and 2/3 power, I idled the engine to drop sails and moor the boat. Engine died and would not restart. We took a tow in and ended the season.

Last year in Spring I took the boat for service, only to stall half-way after running for about an hour. A friend brought some methyl hydrate which we added to the fuel, and we blew through the line to attempt to clear any blockage - the ragged running of the engine suggested a fuel starvation problem.

After 30 minutes or so the engine restarted, and so I handed the boat over the boat yard manager who convinced me to install new fuel lines, a Rakor filter, and an electric fuel pump to pull the gas through it. Electronic ignition was added, as well as new plugs and wires.

After the service the engine seemed to run well, however issues soon developed:

1. The electric fuel pump wasn't working -- I rewired it myself by adding a new hot lead from the engine cutoff switch. Now it spurts gas at the carb whenever I test it.

2. The common ground for some house wiring is gone; I rewired the house water pump with a ground directly to the gear housing. The mast light stays on whenever the batteries are engaged.

I think the mechanic was a little clumsy, or changed the wiring while installing the fuel pump. These are not critical issues for me, I will rewire at some future time. Just more data points.

This season I have completed a recent journey with the following symptoms:

3. Fairly constant loss of coolant, needing 1/2 litre for 30 minutes engine time. First noted when engine overheated with steam in the exhaust. I thought at first it was oil burning, but the cloud was white and smelled like antifreeze not stinky like oil.

4. During the same hot-engine breakdown I pulled plugs 1 and 2. Both looked okay, but I saw no fuel in the cylinders while cranking. Maybe it just evaporates in the hot engine. No obvious issues in the cylinder or plugs.

5. At the same time I tested for spark -- good spark. Tested for fuel at the carb -- lots of gas.

The engine restarted after ccooling, but once again stalled and would not restart when we slowed down to begin mooring.

So I tested a few things:

6. Thermostat works fine in boiling water.

7. Oil at Low mark, I topped it up, lubricant was a little dark but no obvious water.

8. Engine always starts easily and runs fine at idle, or while cool.

It's dificult to access the carb, although the fuel pump and filters are available. The other side of the engine is somewhat accessible, and the head area is exposed under the companionway stairs.

I am tempted to remove the head but I'm experienced mechanically just enough to know that this may introduce more issues, and right now the engine runs, enough at least for local sailing.

I hope the forum can offer me suggestions to diagnose the problem. I am motivated, have tools, shore power, flashlights, and a multimeter. I can rent or borrow a compression tester and know what it is for.

Where do I go from here?

- Jon

[Dave Neptune]

Sounds familiar sort of

Jon, first thing welcome to the Afourian Forum!
Lots os stuff listed to dig through. Did you check for spark when the engine stalled? Your ignition upgrade may not include the properly rated coil and it is "opening" once it gets hot and then "closes" after cooling to fire up again. There has been much todo regarding this on the forum.
As far as the coolant leaking do you see any in the bilge or leaking anywhere on the engine? If not and you are using that much coolant it's probably time to check the intake/exhaust manifolds integrity. Not to bad of a job.
Don't R&R the head unless it is needed and it is not YET! A simple compression check will let us know if you are loosing coolant throuugh the heads gasket. Have you done a compression check?
Remember to close the water intake while cranking in hard starting diagnosis so you don't fill the exhaust risking water encroachment from the exhaust side to the engine .

Dave Neptune

[Bold Rascal]

Welcome Jon!

Your going to receive some very good advice from this forum.
If you already have a manual that's the first place I would start. Excellent trouble shooting guidelines are there. If you don't have one, get one....

180deg F is pretty close to normal temp for the A4.
The symptom of the engine failing and needing to cool before it will restart is most likely electrical. There have been many recent threads discussing this symptom.

The loss of coolant out the exhaust should be concerning. Hopefully it's just a failed gasket. Have you performed a thumb compression test on all cylinders? Do get yourself a compression tester and document your compression on each cyclinder. Your looking for consistent readings from all cylinders.

It's a Good idea to keep checking that oil for water contamination.

Do you need to choke your engine at all when starting it cold? If not or very little you might be running a tad rich on your fuel mixture.

If your satisfied that the engine runs well enough for local sailing it's your call to delay seeking out and correcting the problem(s). If you choose to sail be safe and extra deligent to monitor your engine and fluids at regular intervals. Like before, during and after each sail.

Again. welcome to the Forum.

Mike

[ndutton]

Compliments on a detailed description of symptoms, so detailed in fact that what's not there may be informative too. I think there might be a combination of problems.

Coolant loss
The first thing I'd do is pressure test the manifold. This can be done with the manifold on the engine and is pretty straightforward. The test will eliminate or confirm the manifold as the cause of the coolant loss and point you in a direction for repair.

Original stalling problem
It sounds like it may have been fuel related as you and the mechanic suspected. The addition of a fuel filter and hose replacement probably resolved any fuel contamination problems from then on but here's one of those things you didn't say. I didn't see where the carburetor was cleaned and rebuilt. If you've owned the boat for 6 years, had possible contamination problems and haven't rebuilt the carburetor, it's overdue. It should have been done when the filter was added for a complete repair. Even if the carburetor is clean, where's the harm?

Electronic ignition upgrade
We're all thinking the same thing. Let me ask this specific question though: you correlate the current stalling problem to engine temperature but can you instead tell us the time line in a stalling episode? What we're looking for is somewhere around 45 minutes run time before the engine slows and dies much like fuel starvation. Following a 20 minute or so cooling off period she'll start only to stall again after a little less run time.

Here's my guess of what's gone on:

• 24 year old installation with a deteriorating fuel system. Possible hose decomposition due to ethanol in non-ethanol rated hoses and possible tank contamination. Issue resolved with hose replacement and filter addition.
• Electronic ignition upgrade performed at the same time as the fuel system repairs which brought on another problem with similar symptoms as the previously resolved fuel issue. You traded one problem for another. I did not read the coil was replaced in the EI upgrade. This is critical with electronic ignition.
• I don't think the coolant loss is contributing to the stalling problems.

[Jon K]

great suggestions, will follow up

Okay, Neil Mike and Dave, thanks for the quick response and your suggestions!

I will check the coil type and model, I assume it is new.

As for coolant, there is no obvious leak or coolant in the bilge, but I will put down a clean rag to see what it picks up.

The mainfold integrity tests -- does that mean I should remove the hoses and try to pressure test the exhaust manifold from outside the engine? I'll have to do some research on the forum to find out the best way to do that test.

As for how much choke when starting, I always use full choke when cold but it isn't needed when the engine is warm, however I have never tuned the carburetor. I will need to understand the carb and clean it at some point. So it may well be running rich right now, not sure.

Compression test, either with my thumb or a tester, that I will do asap as well.

To Neil's question of the timeline before stalling, 45 minutes is an average, never less than that anyway. If it is specific to how hot the engine gets, longer times before a stalling episode may occur during lower engine load/rpms I suppose.

I did make a 3.5 hour crossing only to stall on arrival when going to idle. That has happened three times at least after the cooled engine was restarted during a journey including last week.

And Mike, the reason I considered pulling the head was due a suggestion that there might be a blown head gasket. That is unconfirmed and would take me out of commission entirely until completed -- but I am committed to diagnosing and solving these issues with a still-running motor. I would rather sail/cruise but first priority is a reliable engine!

Also, I never knew about water encroachment via the exhaust, I will close that port next time I'm cranking for more than a few cycles. Will try to remember to open it after as well!

Thanks again for pointing me in the right direction, I'll return with more information.

- Jon

[roadnsky]

Jon-
Here are a couple of threads to read thru regarding your manifold testing...

http://www.moyermarine.com/forums/showthread.php?t=6254&highlight=manifold+pressure+test

http://www.moyermarine.com/forums/showthread.php?t=5447&highlight=manifold+pressure+test

[Jon K]

compression test, rich mix, run hot, ignition photo

I did a compression test with the following results.

All plugs were somewhat black with carbon.

Cold compression test

#1 - 90
#2 - 95
#3 - 100
#4 - 95

Oil pressure at high rpm: 34 psi

Engine started cold with no choke.

I ran the engine with saltwater cock closed, it soon overheated to 212/220 with lots of steam in the exhaust (photo below). In that process it ran hot (180 to 200) for 10 minutes without failure. Dropping to idle while the temp gauge read 220, it did not stall.

The electronic ignition seems to be the new item attached below the distributor (photo below). The new coil seems to be a tall black can 3 inches in diameter by 6 inches tall with the main distributor wire coming out of it. Both are new; no brand or model number visible.

I have attached today's photos of the steamy exhaust and oil pressure and temperature gauge during today's hot run, and a photo of the new ignition components.

Questions:

Still unclear about the steam in the exhaust -- what are the possibilities.

Does the compression test rule out head gasket failure or other issues.

If the ignition system (coil, electronic ignition and wires) came from Moyer last year, when the boat was in the shop, does the picture agree. If so, or if not, how to test coil failure etc.

Last year the mechanic ordered ignition parts from the East Coast, likely to have been Moyer Marine.

Neil's description of the failure scenario (45 minutes run time) seems very close to my symptoms. They seem to have persisted through a fuel system upgrade and electronic ignition upgrade. What does this indicate?

Thanks for the input,

- Jon

[Jon K]

photos from today's hot run

Here are photos of the exhaust when deliberately overheating the engine, the oil and temperature gauges at that time, and the new ignition system installed last year which did not solve my stalling problem.

- Jon

[ndutton]

First, the coolant
Considering the amount of steam, if this were coolant in the combustion chamber the plugs would show it - and they don't. The compression numbers are great. They may have been skewed up by coolant in the cylinder but again, the condition of the plugs indicates that's not the case. Your test with the raw water valve closed and copious amounts of steam still present leads me to a single conclusion - the manifold. You really need to do that test.

And . . . you now need to replace your impeller too. Running it dry for 10 minutes is destructive.

Neil's description of the failure scenario (45 minutes run time) seems very close to my symptoms. They seem to have persisted through a fuel system upgrade and electronic ignition upgrade.

This assumes neither upgrade solved anything. As I said in my earlier post, I think your fuel system work either solved or came close to solving the original issue (see below for carburetor comments). But you changed more than one system simultaneously, usually considered to be bad form when troubleshooting.

You also upgraded to electronic ignition. You said you think the coil was replaced (looks new to me) but you can't say with what. You said it might be a Moyer coil but you're not certain. Your run time and failure symptom strongly suggests you have a coil of insufficient resistance for electronic ignition and it doesn't matter if it's new or not. It's the balance of your unique coil input voltage and the coil resistance that matters and coils come in a variety of resistances. A crude estimate is your coil resistance should be 4 ohms (Shawn, where did you get that Omega symbol I saw in another thread??) There's a painfully long thread on the subject found here. Note that the coil issue is unique to electronic ignition and entered into the mix when the ignition upgrade was performed. Also, it's not affected by engine running temperature, at least not the temperatures you are reporting.

I apologize for repeating what I theorized in my earlier post but I still think the current failures are unrelated to the previous failures. I think your fuel system work went a long way toward solving the original shut down issue then the installation of electronic ignition introduced a new issue with a low resistance coil. You're thinking the problem persists, I think the current problem is entirely different from the original problem. Please remember this is theory only, we're guessing the best we can.

About those plugs - their color indicates a mixture that's too rich as does this:

Engine started cold with no choke.

You're getting way too much fuel. A carburetor rebuild and dialing it in after reinstallation is in order. If you're apprehensive about it, consider Moyer's instructional video offerings.

[sastanley]

quick hijack

A crude estimate is your coil resistance should be 4 ohms (Shawn, where did you get that Omega symbol I saw in another thread??)

Neil - ALT + 234 on the number keypad gives you Ω.

Incidentally, ALT + 248 is °.

Here is a link to a resource. http://www.alt-codes.net/

[Jon K]

next steps

Thanks Neil.

I'll do the following:

1. Test the coil resistance and post the results.

2. Try to find a cheap way to test the cooling system manifold pressure.

To do this I need to get some kind of pressure gauge into the system, and either run the engine and coolant pump to generate pressure or add a tire pump into the mix.

I'll have to see what I can do about finding a schraeder valve and coupling it into the cooling system to add a tire pump with a gauge, or another inexpensive alternative.

3. Yes, time to change the impeller. I have a spare from the previous owner but haven't replaced the impeller, just made sure I know where it goes and that I have tools to change it if necessary. I'll get a new one.

While thinking about this, I know there are two water pumps, the lower rear one has a grease cap that I should fill too. Do I need to service the coolant pump immediately?

4. My resistance to doing the carburetor rebuild is simply that, on my Ranger 28, the carb is located behind and below the access panel inside the cupboard beside the companionway stairs.

So I can see it from the cabin, and could possibly see my right hand going through the cupboard doorway, through the side access hatch and possibly reaching the carb with some kind of tools, since my head and arm don't both fit in the cupboard at the same time!

One of the strangest things I've seen in a while was the mechanic lying full-length inside the empty port cockpit locker, adjusting the gearbox. Quite a feat to get in and out I'm sure, and lots to bump your head on. The sole locker is usually chock-full of lines, fenders, boathook, ladder, shore power cable etc. I never considered it as an engine access method, but there you go.

I'll have to think through the carb work, at the very least take a good look at the manual to identify the screws and see if they can be adjusted without losing too much skin from my knuckles.

Thanks for the on-track advice.

- Jon

[sastanley]

Jon...a bicycle pump will work fine. The tricky part is the schrader valve to NPT fitting..some better hardware stores may carry them..or a place like McMaster Carr for sure, or even Amazon, has them.

Then you just need to cobble together a couple of bushings, reducers, etc. to thread it all together. By the way, the manifold threads are 3/8" NPT.

I've never had to do it myself, but, I am sure you can find more info here on this site with some creative searches, or maybe someone that has recently done so, can post their advice..

[ndutton]

Jon,

I think your breach is big enough that you can test the manifold with your thumb as a gauge and a piece of 5/8" hose to blow in. Remove the two hoses on top of the manifold leaving the fittings in place. Clamp the test hose onto one fitting and blow into it with your thumb blocking the other. If you can develop enough pressure to either feel it on your thumb or turn your face red your manifold is intact, anything less and it isn't.

To test the coil, be sure to remove the wire(s) from at least one of the terminals and read the resistance between the two small terminals. To test it's suitability for your ignition system you also should measure the voltage between the coil + terminal and the engine block while the engine is running above 1000 RPM and then apply the formula or use the calculator, both found in the Coil Input thread (link provided in my previous post).

If it turns out that these tests result in properly operating systems, that's good information too. We can look elsewhere.

edit:
If you're concerned about carburetor access, all you really need access to are the cables, fuel line, scavenge tube and 2 mounting bolts. The delicate work is done on the bench. For adjustment after reinstallation, consider the Moyer idle adjusting needle with knurled extension. Get a 6" piece of fuel hose that's a snug fit over the knurled extension and use it as an extendo-handle to turn the adjustment screw, easily reachable from the front of the engine.

[edwardc]

Jon...a bicycle pump will work fine. The tricky part is the schrader valve to NPT fitting..some better hardware stores may carry them..or a place like McMaster Carr for sure, or even Amazon, has them.

I took a different approach to this. I bought an automobile tire rubber valve stem and used an xacto knife to cut off the "mushroom" part of the base. The remaining part of the valve stem could then be easily inserted into a hose and clamped to seal it. The other end of the hose then gets clamped onto one of the manifold fittings.

[Chris T]

I took a different approach to this. I bought an automobile tire rubber valve stem and used an xacto knife to cut off the "mushroom" part of the base. The remaining part of the valve stem could then be easily inserted into a hose and clamped to seal it. The other end of the hose then gets clamped onto one of the manifold fittings.

Ingenious!!!!!!!!!!!!!!!!!