6BTA-M1 shuts down and will not restart

[Quench]

Hi – 1995 Albin 28 – 6BTA, unknown hours.   We’ve had it about a year now but only put about 60 hours on it.  

A few months ago it died suddenly under acceleration.   It restarted about 30 minutes later after several tries and seemed to run fine.  Not knowing much at the time, we asked the mechanic to look over the fuel supply and he reported back that the filters were clean and there didn’t appear to be any problems.  It has performed really well in several outings since then.

Yesterday, it did the same thing – immediately died under acceleration.   However, it would not restart this time.  We checked that the fuel solenoid was functioning when trying to restart.

The hints that I’ve found on the forum here suggest an electrical problem, but I’m not sure where to begin with that.  I have plenty of pics – just need to know what you want to see.

Topic

[Quench]

Update

We’ve tested and found that the fuel solenoid isn’t the issue.  Unfortunately, it died again yesterday, requiring another tow.   Tried restarting by manually holding the fuel shutoff open but didn’t even get a pop.  Further, we’re not getting any fuel out of the exhaust while trying to start.  So we now think this is fuel issue. 

The tank should be adequately vented, with a new tube placed last summer.  Also removed the fill cap yesterday and there wasn’t any vacuum.  The first filter has a full bowl.  The line from there to the low lift had fuel, but not much.  It’s roughly even with the tank, so I wouldn’t expect gravity pressure there.  The plunger on the low lift seemed difficult to compress, but I don’t have a frame of reference.  I loosened the banjo after the low lift and got a quick puff of fuel/air (I think – it happened quickly).  Stopped at that point because at this point, I don’t know enough to move forward with testing for flow in this system.

Need some guidance on the next step in diagnostics please. 

 

[Clark Leighs]

I should have mentioned that if you measured 12.8V at the battery while cranking actually that is the wrong place for measuring.     The battery could show 12.8v  but a few poor connections away the voltage could be way down.     Measure the cranking voltage at the starter terminals or at the fuel control valve terminals.   As far as FAIRLY tight that may not be good enough.   They need to be CLEAN and  TIGHT.    All it takes is one poor connection to cause trouble.     

THe 12.8 could have shown due to any resistance in the wiring restricting the needed current flow to the fuel control valve and the starter motor in which case the battery showed more voltage than it should have.

 

 

I am going to suggest also that once sorted out you pay attention the the sound of the starter and how fast it spins the engine.       I have had problems over the last 40 yrs and one of the quickest tip offs that some work is needed is hearing the starter motor just a bit off.    We boat in cold weather and that does make difference but it should not make a huge difference unless there is also a brewing problem.

 

[Clark Leighs]

I don’t know your engine to be clear.    

 

It is possible the rod did not retract fully?    Did you try pushing it all the way?    Did you check the voltage at the electrical connections of the solenoid?     Is that where you got the ~12.5V. while cranking?   If so that sounds ok to me assuming the rod pulled back all the way.    Try pushing the rod while voltage is applied?

How about the linkage , is it stiff or sticky?    Sometimes these solenoids need a bit of servicing help such as a spray lube for them to overcome internal friction.   Spray while the rod is out and as it is retracted.

 

If I remember correctly that voltage must be maintained continuously for the engine to get the fuel to operate. 

[Quench]

Thanks for the response.   It died like the key was turned off.   Not like an engine starving of fuel.    That’s why we’re looking at electrical issues, but it does seem that the solenoid is the only electrical component on this engine.  And when we were trying to restart it, the solenoid appeared to be working correctly – meaning that the pushrod retracted.  But it still wouldn’t restart (not even a pop).  Is it possible (likely?) that the pushrod didn’t fully retract and doesn’t open the valve?  Also, is the valve just either open or closed?  Interesting that the batteries may be the cause.  I’m fairly certain that the connections are tight, but the voltages were a bit low (12.5ish) after this episode.  That could be due to several attempts to start the engine.  

[Clark Leighs]

When it shut down initially did it hesitate, stumble or try to continue to run although stumbling.   This may indicate fuel starvation.  Filters quite dirty, air leaks in supply lines. Look for wet spots and use paper towels to wipe and pick up any traces of fuel.   , I like the Blue shop towels as they show a distinct colour change if wetted even minimally.

Or did the engine simply shut down quite abruptly?    This  would indicate electrical problems, likely one or more poor connections.

Have you checked for poor connections at the Batteries?    Loose, dirty , corroded, including crimped connections. Do your clamps use wing nuts , a very poor nut for this purpose.  They should ( must) be a HEX nut.  Are the  connectors  clean and bright on the inside of the clamp.    Are the battery posts clean and bright?  Are the battery post clamps tight, no slippage.  If they cannot be tightened then get new ones with hex nuts.

Checked the battery cable clamps that they are clean and tight?.  You will need some tools, basics  such as a couple of wrenches, sandpaper.   I also use a LIGHT coating of  Penetrox Electrical paste to help keep corrosion at bay on the posts/clamps.  There are others that will suffice.   Tis messy so have some paper towels handy.

Do you have a DMM?  Learn to use it and use it as you go even here. Often they can show high resistance across connections.    Any thing generally more than  1 ohm  in a starting circuit is going to be trouble at some point.

For  DMM use purchase a long set of leads or make them  for both polarities and use them so you can watch the Vdrop while testing.   You must be able to see the readings.   Use strong alligator or bulldog clips.  

Use the DMM on voltage setting and check the voltage while cranking at the battery posts.    Should NOT drop below ~ 10V.       Better higher.

Your fuel control valve, allows fuel  to the injection pump, should show about 80% of the 12V of the batteries to pull in initially at the control valve.   If not then start looking for poor connections.  These solenoids usually need at least the 80% battery voltage,  then about 60% to stay pulled in.   THis solenoid is what turns the fuel to the injection pump on.

See how you make out.

 

 

 

 

 

 

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