I'm in need of some help. (sfdf0623)

[Administrator]

Here's a "reprint " of a visitor message from sfdf0623:

I'm in need of some help.
A4 starts good when cold and runs well for about an hour, when it seems to starve for fuel. If, at that time you squeeze the ball between the tank and fuel filter/separator it seems that there is no fuel in the line. But, then, after about an hour, she starts right up/runs well for about an hour. And the cycle continues......
I'm thinking either the ball pump is bad or the fuel tank vent is clogged. Any help/suggestions will be most appreciated....PLEASE HELP!!!!!!

Bill

[ArtJ]

unless the engine gradually stops. the one hour cycle sounds familiar to the
Electronic Ignition excessive dwell issue which disables ignition coils and heals them
selves after an hour of cooling. I tracked this issue for a couple of years
until others discovered the reason.

[ndutton]

it seems to starve for fuel. . . . and . . . . it seems that there is no fuel in the line.

Let's find out for sure. There's no point in chasing a fuel issue if there isn't a fuel issue.

Step one: next time run the engine with the deck fill plate open. That will take a possible clogged vent out of the loop. If the engine runs well, look at the vent. If it dies as before, it's not the vent, period.

Step two (if it dies in step one): immediately upon shut down remove the main passage plug at the bottom of the carburetor bowl with a catchment underneath. If about ¼ cup of fuel runs out there is no fuel supply problem. Proceed to step three immedaitely.

Step three: close the raw water intake thru-hull, remove the coil wire from the center of the distributor and hold it about ½" from a head bolt. Have a crew member crank starter for one second and observe for spark jumping from the wire to the head bolt. No spark? There ya go.

I suspect Art's observation is where you'll end up. We've heard it over and over, runs for 45 minutes (or so, your one hour report falls under the 'or so' umbrella), engine dies gradually mimicking fuel starvation, will not restart until after a 20 ~ 30 minute cool down period. That's the classic overheated coil symptom set. The question then is why did it overheat?

Don't forget you removed the passage plug in step two and closed the thru-hull in step three.

edit:
Steps two and three can be reversed in the interest of time. It's much easier to check for spark that it is for fuel.

[sfdf0623]

Thanks guys. I had thought about #1 but with #'s 2 and 3 perhaps this mystery can finally be solved.

If # 3 it needs a new coil right?

Curious........to perform test #3 why close the raw water intake thru-hull. Also, is meant by ndutton's question .... why did it overheat?

Gracias

[ndutton]

We are religious about closing the thru-hull when cranking the engine to insure against the risk of overfilling the waterlift muffler and backflooding the engine. I'm currently parting out a seized Universal 3 cylinder M25XP diesel that was destroyed exactly that way.

You are correct that no spark when warmed up will likely require a new coil but unless we figure out why it overheated in the first place you're doomed to a repeat performance.

Let's not get ahead of ourselves though. Let's find out for sure if we're dealing with a fuel or spark problem first. We can proceed from there.

[joe_db]

Quick test:
When the engine quits, squirt a little ether in the carb and crank. If it is out of gas, it will run. If it is out of spark, it will not.

[nyvoyager]

i suffered thru this problem some years ago and for diagnostic purposes i installed a glass inline filter to visually access fuel flow.
this is not USGS compliant and i would reccomend doing it dockside.

eventually rebuilt the entire fuel system front to back including removing the tank and having all the crud cleaned out. the hose from tank to fuel pump was filled solid.

[sfdf0623]

I'm afraid I may have damaged the motor by repeatedly trying to start the motor
while the intake hose thru hull was not closed. No obvious problem so far but.............
Overheating???? Not according to the temp. gauge.

[sfdf0623]

Oh, and there is a clear filter between the fuel pump and the carb. and it has fuel in it. As well as a small bubble of air???

[sastanley]

sfdf, what happens when you crank with the thru-hull open is the muffler fills up as the water pump is spinning while cranking. Since the exhaust system relies on the engine running to batch the water out of the exhaust system, when it is cranking and not running, the water backs up the exhaust and eventually dumps into the cylinders via the exhaust valve. Usually, if you do not remedy this situation immediately, the cylinders walls rust and freeze up the engine. This then requires you to remove the head to clean things up and get her moving again. By this time, some of that water has also seeped down the piston rings and likely gotten in the crankcase too.

Fortunately, I have not done this myself yet, but the P.O. on my boat apparently removed the head more than once to scrape rust off the #4 cylinder wall and free up a stuck/rusty valve, when he cranked and cranked and couldn't get it to start and then let it sit a week and she was frozen solid.

[sfdf0623]

Forgot to mention that i live 2 hrs away and have only 1 opportunity to go the boat before our planned boat vacation. Thus Im trying to gather all pertinent info. so that only 1 trip to the boat is needed to solve the problem.
If it is determined to be the coil, will a new coil solve the problem at least temporarily. Or will it also malfunction when it gets too hot?
ANY other ideas or suggestions are VERY welcome

[hanleyclifford]

Originally Posted by sfdf0623

Forgot to mention that i live 2 hrs away and have only 1 opportunity to go the boat before our planned boat vacation. Thus Im trying to gather all pertinent info. so that only 1 trip to the boat is needed to solve the problem.
If it is determined to be the coil, will a new coil solve the problem at least temporarily. Or will it also malfunction when it gets too hot?
ANY other ideas or suggestions are VERY welcome

If you buy a new coil and only get one shot for the fix bring along a voltmeter and stop off at Radio Shack for an assortment of resistors in the 1/2 to 2 ohm range. Buy the coil that says " no external resistor required" (but it does).

[JOHN COOKSON]

Good luck on getting the engine diagnosed and fixed in a single trip to the boat.
We don't know what the problem is yet: fuel or spark.
If you want to try it with an assortment of parts, some in the forum have made A4 house calls. They can advise what to take along in the way of parts and tools.

Originally Posted by sfdf0623

Forgot to mention that i live 2 hrs away and have only 1 opportunity to go the boat before our planned boat vacation. Thus Im trying to gather all pertinent info. so that only 1 trip to the boat is needed to solve the problem.
If it is determined to be the coil, will a new coil solve the problem at least temporarily.(?) Or will it also malfunction when it gets too hot?ANY other ideas or suggestions are VERY welcome

The answer to both questions is yes. Once a coil starts to overheat its duty cycle becomes shorter and shorter until the engine won't start at all. Obviously it is necessary to find the cause of the overheating.

BTW: The " bubble" in the filter appears because the diameter of the filter is greater than the diameter of the hose. It is not a reason for concern.

TRUE GRIT

[ndutton]

It sounds like you want to replace some ignition components on principle alone and I don't see any harm in that as long as it's done right. If it's not done right you'll simply cause other problems. Following up on what's been said so far:

• Coil - if you're getting a coil from somewhere other than MMI (sounds like you are) it should be specified with 3Ω internal resistance (typical value) and preferably oil filled as opposed to epoxy filled.
• Resistor(s), part one - if you get your resistor(s) at someplace other than an automotive source be sure they're rated for approximately 60 watts. If they're significantly less you'll destroy them for sure and you'll be troubleshooting again, exactly what you're trying to avoid.
• Resistor(s), part two - There are basically two flavors of advice on the forum regarding resistor sizing. What's been suggested is buy an assortment and go through the trial and error, guess and check process. The other flavor is to read up and follow the findings reached a couple of years ago on ignition system amperage, how it's related to other factors and how to get a single resistor of a suitable size. There was a considerable amount of work, vendor consultation, applied electrical formulae, testing, retesting and measuring that went into it, all of it published in the 'Coil Input' thread (and a few others). That work even caught the attention of an MMI competitor who subsequently developed a resistor product shortly thereafter. To date there has not been a single coil failure reported by those who faithfully applied the recommendations, absentmindedness notwithstanding.

So there you have it. You get to choose between the trial and error, guess and check approach or take advantage of the previous work that was done on the subject and published specifically for this application.

Good luck

[hanleyclifford]

Here is the thread Brutha Neil is talking about: http://www.moyermarine.com/forums/sh...ut+information If you have time to read it and if you can get the resistor you need in time.... Either approach will work; but if you want up front precision, Neil's da Man.

[ndutton]

The constant mention of the warm fuzzy approach suggests that in the mind of some there's something either wrong or lacking in the EI/coil work mentioned in the earlier post. Maybe someday we'll understand what it is.

Either approach will work

. . . . but achieve a completely different end. For example, the warm fuzzies may require a starting circuit resistor bypass just to get the engine to start whereas the researched, calculated and tested approach will not.

[hanleyclifford]

Originally Posted by ndutton

The constant mention of the warm fuzzy approach suggests that in the mind of some there's something either wrong or lacking in the EI/coil work mentioned in the earlier post. Maybe someday we'll understand what it is.
. . . . but achieve a completely different end. For example, the warm fuzzies may require a starting circuit resistor bypass just to get the engine to start whereas the researched, calculated and tested approach will not.

Dear Neil, For the record I find nothing wrong in your calculated approach and do and always will respect your many years of electrical experience, not to mention your years of boat construction experience. The Coil Input Informaton thread is a masterpiece and worthy of scrutiny by all Afourians. However, it is also true that the "warm fuzzy" approach has led me and others thru many years of engine experience including in my case seven liveaboard round trips up and down the Atlantic coast under nearly continuous A4 operation. Can we not agree that there are often many different ways to skin the same cat? Your A4 Brutha, Hanley

[ndutton]

I'll agree that a guy can guess and check his engine to run but I won't agree that it's in the best interests of members asking for help from a high quality forum. What if someone suggested tightening the head bolts down only enough so she'll run. You don't need a torque wrench, a manual or compression gauge, all that's really needed is to get a good enough seal. As an endorsement the purveyor of such advice states, "That's how I did mine and it's run fine for years."

We'd never dream of letting that pass, would we? Could it work? Well yeah, it could.

One other inconsistency:
It's interesting that while advocating a fuzzy guess and check approach to ignition circuit design such is not the case when it comes to timing. I just researched several posts (no need to quote them here but search "timing light" and specific author) stating that accurately setting the timing with a timing light is the only way to get it right (as opposed to power timing).

[hanleyclifford]

As in all things, each member of the Forum does and should evaluate each opinion FWIW.

[ndutton]

That's fine. I had my say, feel better that I did. On to other things.

[sastanley]

So, I am on the warm & fuzzy approach with coil stuff right now..If I recall, I have about 3Ω of resistance in line in front of my Moyer coil, and I have the "R"?? terminal connection from the starter to the the coil to aid with starting voltage.

However, I also cannot get my engine timing right with a timing light, and find it impossible to get the engine timing to the 34° crank degrees without (what I think is) pre-detonation occurring.

So, some of us are in the middle of the two extremes in our new friend sfdf0623's thread.

[ndutton]

Shawn, I'm glad you came in here. You have valuable experience to offer with the fuzzy guess and check approach.

During the course of trying to get your ignition system reliable how many coils and how many resistors have been involved? How many problems along the way?

And I'll say it first, in your defense I remember you received some questionable tech advice from Pertronix that complicated matters further.

[sastanley]

Neil,

I will predicate this post with the fact that I am at home in the garage & working on memory..some details may not be clear or completely accurate since I have not seen the boat in several weeks and I am not good at keeping notes.

I have 3 different resistors I've tried at various times. 0.63Ω, 1.2Ω & 2.1Ω. I carry them all onboard and currently have two inline.

Originally, Pertronix recommended a 1.5Ω coil to go with their 1146A EI unit. That lasted about 60 minutes. So, I got to the other extreme where I had the 2.1Ω resistor in front of the Pertronix 3.0Ω coil attached to the 1146A electronic ignition. This worked for several multi-hour motoring episodes with no real trouble.

However, I was still having trouble with that set up. Granted, I have a (now 2 seasons old) brand new all BlueSea parts and tinned marine wire, heat shrink fittings, etc., ignition harness, and I also run an aftermarket regulator that I can dial in the voltage. Neil has always been on my butt about the aftermarket regulator spitting out too much voltage...I am seeing 14.18-14.25 at the batteries. The voltage at the coil varies, depending on alt. output, but it is in the 11.7-13v range with that set up. But the engine was not always reliable again, after being so for two seasons. I did find a loose connection in that fancy new wiring harness and thought all of my woes were solved!

But occasionally this summer, I would have random unexplained shutdowns after a long engine run. So, I kept replacing coils (late this summer I gave up on Pertronix and bought a Moyer coil with a measured 3.7Ω resistance).

So, my CURRENT setup is the 0.82Ω and 2.1Ω coil in series in front of the "Moyer" coil. I did this because with the low voltage loss of the new ignition harness, I was still seeing ~12v at the coil (+). So, I added the "R" terminal line to the coil (+) which only is active when the key is in "start" to help the coil fire up quickly. That seems to work pretty well now. I can start instantly, and I thought the running coil voltage was OK, which I recall to be in the 10.5v range.

In full disclosure since we are all pretty good online friends around here, I do occasionally still have an unexpected shutdown when I go to idle after running for a while. Recently when single-handing, tiller pilot engaged in a stiff breeze at idle to hold the boat steady while folding sails, the engine quit. It restarted & ran a little funny and I got where I was going. So, I naturally think that was still caused by too much voltage to the coil. The result for the rest of the trip was to use the engine as minimally as possible to ensure it would run when I was by myself and needed it. However, after removing myself from the boat and situation for a bit, I now think I may have been 'over anxious' on my resistors, and when the alternator ceases to charge at idle, the coil simply does not have enough voltage to run the engine, and it stalls...possibly with things like a tiller pilot amperage draw adding to the mix. I think what I need to do is go get concrete measurements again (not warm & fuzzy) and take good notes. The bottom line is the engine has been reliable at speed, but unreliable at idle this fall. I have all winter tugging on the docklines to figure it out..whether my conclusion is mathematical or warm & fuzzy.

I'll probably edit this post as I re-read it and see errors or omissions, so stay tuned.

[ndutton]

That's pretty much how I remembered it Shawn. It was your experience I was eliciting, good, bad or indifferent. It is what it is.

[sastanley]

Neil,

I like boats. I see myself as a pretty humble person & I've been around boats my whole life. Until I got this boat in 2008, I'd never owned my own boat bigger than a Laser. I still get very nervous as the owner/skipper (especially if other people are aboard and relying on me) but, I am a confident boat person.

I try not to put myself in a position I cannot get myself out of given the things I have to work with..(ask me about the day the engine wouldn't run and we are tacking every 10-15 or 20 seconds out of the little creek with 50 yards of width between marina piers and the crazy people in kayaks and stand-up paddleboards that just launched from the local church are paddling beside us and chatting it up with Laura like there's no issue, and I am busy trying not to squish them in my 10,000 lbs. boat!!! - That was the day we were leaving the pump out station and had to sail the boat to the travel lift for haul out. I think we did 15+ tacks in about 3 minutes to make it out of a 200 yard long creek. I was freaking out, but all the other people around us on that sunny August day had no clue.. (Laura knew but she was her normal cool-as-a-cucumber wife and silently worked with me helping the sail around the shrouds all the while carrying on with the crazy lady 6 feet away in a kayak not realizing she'd be squished if we went one more boatlength.)

...ok, well i just told you all about it so you don't have to ask.

If I can help one other person have an easier time and enjoy sailing & boating by sharing my stories & troubles, I've achieved my goal.

Sorry about the hijack!