Somebody thinks I know something about A4's..now I am an 'expert'!?!?

[sastanley]

Mo...sorry about the bad news. I saw the Lopo at the boat show this weekend..they look sexy, but I can't justify the cost...

My cheap LED's from boaterbits have been working just fine so far..only installed for several weeks.

BTW- I have not been back to the Sabre 28 yet...too many issues with my own boat right now to help others.

[Mo]

Hey Shawn,
Good thing is they will give me another one. They didn't even want the old one back...just the serial number. Must be a problem they know about...not a good sign as I don't want to go through this again. I was thinking of giving the old one to an electronics geek and see if he can fix it. Time to call in the Navy on that one.

I rewired the mast and put that light on about 18 months ago.Thought for sure an electrical problem....was a little P'ved when it turned out to be the light. I always hated messing with mast-head lights and that's why I bought the one that was supposed to last FOREVER... I just don't want to be doing this again any time soon. I have to take my mast down every time something like that happens because I have all connections running through conduit inside the mast.

On the bright side of things. I've put a spinnaker extension (for pully) on top of the stick as the one there really didn't extend far enough...1/4 inch stainless steel bolted on; checked and lubed all pulleys, checked all stays and running rigging. Painted the boom, painted some areas of the mast that had rubbed through (just no desire to do the whole thing); new leather covers on jack-stay pulleys, took some matched teal paint and painted the portion of mast that extends to the keel inside; also painted mast-step holder; removed flooring under mast-step holder and put a new piece (although it could have done a couple of more years). The actual mast step is made of high density foam (same stuff used on space shuttle), kevlar, epoxy...I did that 4 years ago and it is ROCK solid...so no problem there.

....anyway....just waiting for the light to show up and the stick goes back on. I'll have to haul out the end of the month but at least the stick will stay on and I (hopefully) won't have to deal with it for another few years.

[sastanley]

Sabre 28 update - putt, putt, putt..but won't quite catch

My old buddy and I met up yesterday afternoon to fiddle with this A-4 again on the Sabre 28. This time I brought along a 20" box fan to help ventilate the cabin.

So..here is the latest..the engine tries to start and fires a couple of cylinders when we are cranking it, but it just won't keep going.

Latest details..but, it won't run...what am I missing?
- Carb was removed and cleaned by me during last visit. (entire can of carb cleaner, wired out jets, etc..)
- I double checked my previous electronic ignition installation
- Made sure we had static timing set via TDC (visual on the roll pin)
- verified compression (the guy I am helping had verified a few months ago with a real gauge, so today we just did the thumb test while confirming TDC).
- Since there was an effective ventilation system, next is check for spark with a plug grounded to the block. YUP!..nice strong yellow-ish spark.
- I visually confirm the choke is fully closed
- Fuel pump happily clicks away when key is 'On' & we are currently pulling fuel from an outboard tank..they are getting a replacement permanent tank fabricated as we speak

After the first round of starter cranking..no dice. So I pull the carb plug to check for fuel since we'd verified spark & compression...yup..we've got a full bowl of fuel..so I clean up what I wasn't able to catch and let the boat air out a bit & try again.

This time, the engine sputters while cranking, but won't stay lit when we let off the starter. This is repeated several more tries until it is getting dark.

Observations while cranking..
- oil pressure comes up to 20 PSI, any OPSS's should be working??
- when key is "on" fuel pump runs and coil has 12 v across the (+) & (-) posts.
- when additional throttle is applied during cranking, the engine stops sputtering..ease back to 15-20% throttle and the engine starts firing again, but nothing when starter is disengaged.

Here's what's next:
- the "new" fuel in the outboard tank is now several months old - so fresh fuel will be brought for the next round
- new spark plugs..no idea on condition or age of current ones (RJ12YC)
- I may bring my plug wires to check..current ones are old & stiff (temps around 50 here on a good day)

Questions for the group: There are (of course) lots of weird things going on with the wiring on this boat. There are wires running to various OPSS's, etc. Assuming the fuel pump runs at "On" and the coil has power at "On" & the engine fires at least one cylinder during cranking, what else do I need to check related to these OPSS's if the coil has power & the fuel pump runs? The engine discontinues to fire as soon as starter is disengaged.
I don't know much about the OPSS's, etc. I would assume one is there for the fuel pump, and it must have a bypass so it will run when key is 'on'.

What is keeping this engine from running?

[ILikeRust]

1. The "few months old" fuel shouldn't be an issue, I don't think. I filled my boat's tank in November 2010, and just a couple weeks ago - the weekend before Thanksgiving - fired it right up, lickety-split, smooth as goose grease through a tin horn, using that gas that had been sitting untouched in that tank for a full year. I did add the marine Sta-Bil stuff, though, which expressly states it is designed to deal with ethanol, so that likely helped. But even without that, I wouldn't think gas that has sat in a tank for 3-4 months would be so bad as to prevent an engine from starting - unless that gasoline had been added to some truly old/crappy gas that was there before.

I don't typically add Sta-Bil to my lawnmower/pressure washer gasoline, and they start right up after sitting for three-four months over winter.

2. Bypass the OPSS with a jumper and eliminate that as a variable.

3. Triple-check the timing to make sure it actually is on the compression stroke (DAMHIKT).

[ndutton]

What he said

Bill said it before I could - #3 - make doubly sure you haven't mistaken the exhaust stroke for the compression stroke for TDC. The crank and roll pin will be in the same position for both. You can hold your thumb on the spark plug hole as you rotate the crank. You should feel a little pressure as the #1 piston comes up to TDC. No pressure = exhaust stroke and you'll be 180 degrees off on the timing. Even experienced hands can make this error. Bill had an expert neighbor (no sarcasm, he really was an expert) lending a hand and he did the same thing.

Plugs and wires are also possibilities as you surmised and there's no downside to replacing them on principle.

[Ajax]

What is keeping this engine from running?

At this point in the story, I am unsure if your distrbutor guts are still parked in his distributor. Have you verified the point gap and condensor? This really sounds like insufficient spark due to point gap. Also, put a little grease on the distributor shaft and cam. (I realize that you observed a yellowish spark)

When I was driving my '74 VW Thing one day, it drove it to work as pretty as you please but 3 hours later, exhibited exactly the same symptoms. I discovered that the points barely had any gap at all, because the shaft and cam were very dry, and wore the cam down prematurely.

Also, what condition are the cap, rotor and plug wires in? If the wires are dry and cracked, you're not getting enough spark to the plugs no matter what the visual indicators are. You can also put an ohm meter on the wires. If they read near-infinite resistances, get rid of them.

[edwardc]

Shawn,

This sure sounds like late timing. 180 out would cause backfires out the exhaust. Late timing would fire, but with no power.

Since you said it has electronic igintion, that eliminates points as a cause.

Try grossly advancing the timing and see if that gets it to start & run. If it
works, it'll give you a place to start looking.

[sastanley]

Ajax, it has a brand new 1146a pertronix EI, that was sitting in a box in the boat when we went down in August...but I know what you mean about a dry cam lobe on the dizzy shaft. I had a '78 Civic when I was a teenager that had a similar problem (mine was the 'adjusting screw' was stripped, so the point gap moved at will) - I could coast off to the side of the road,fiddle with the damn thing and get it running and still make midnight curfew!

The cap is brand new, as I had to cut a notch for the EI wires.

Ed, neil, bill, thanks.

I will double check I am on the compression stroke. Let me make sure I have this figured out. Two full revolutions is one full cycle correct? (i.e. a cylinder fires with every 180 degrees of crank rotation??)

OK, so which way do I spin the distributor to advance the timing..counter-clockwise I think? I discussed this with Barney as a possibility, because I had the same issue when I had my engine all ripped apart a couple of months ago...it cranked and cranked and sputtered, & a flick of the distributor and it ran smooth as you please..but, it had only been down for about 36 hours. This motor has been down 5 or 6 (or more) years...no one is quite sure.

thanks for all the help guys..i am sure we'll resurrect one more motor here soon enough!

[ndutton]

Yes, counter clockwise = advance.

I think the putt-putt you're hearing is combustion out the exhaust as Ed mentions. I'm not sure you can rotate the distributor enough to get her to run due to the limiting length of the EI wires.

There are other issues to be dealt with after she fires. In particular is the electric fuel pump circuit and the non-functioning OPSS, it's where I would start. Note that an OPSS has two terminals, other oil pressure sensors such as the alarm switch have only one, otherwise they look similar.

Since he has Pertronix EI, when all this is resolved you might want to WOW him and measure the coil resistance and running coil voltage as icing on the cake. You'll become a local A-4 legend.

[JOHN COOKSON]

Shawn, Have A Look At This

If there is a wire from the starter to the electric fuel pump disconnect it at the starter and pull it out past the distributor and the coil so you can inspect it.

This particular wire on my A4 was run with no slack and the insulation wore through over time where it turned the corner around the engine back by the distributor. There was an intermittent short at this point.

The implications of this short are clear. The electric fuel pump was shorted out and when the OPSS is closed the ignition system was shorted out all in a glorious intermittent scenario.

Your symptoms are a little different than mine but this is easy to check. Hope it helps.

TRUE GRIT

[hanleyclifford]

I like this last idea. The "R" terminal is only energized when the starter solenoid is being engaged. It is in effect an ignition override. It could be masking a bad OPSS in the main circuit.

[sastanley]

yeah...except I guess I am confused... (what's new..)

The coil has power when the key is on, & the fuel pump clicks when the key is on &I've confirmed spark when cranking. If there is a bad (+) feed line at the "R" terminal going to the fuel pump (12v during cranking only) is it possible this means the fuel pump is NOT running during cranking? Shouldn't there be enough fuel in the carb to have it run for a minute or two anyway even if the fuel pump only works when the key is on and engine is not running?

The whole point of the OPSS is to turn off the fuel pump if oil pressure is low, correct? In a normally configured engine, should there be any other switches designed to override some other condition that would instantly cease the engine from running when the key is moved from "start" position to the the "on" position?

I know this is like the blind leading the blind here...without all these damn 'extra unknowns' (like a mechanical fuel pump!!), I might have it running by now.

Next time at the boat, I'll take some pictures so we can all 'see' what we are dealing with...it ain't pretty.

[smosher]

Shawn, OPSS sensor can open and close at different pressures depending on which one you have. I believe the one Moyer sells closes at 5 - 10 psi. There might be 3 prongs, you want the common and the normally open, it closes at pressure which provides power to the pump.

The negative side of the coil should alternate between +12 and ground.
If your seeing +12 on the neg side when your trying to start this means something in the ei unit is not quite right. The neg side of the coil will fluctuate as the motor spins. A possibility is that both the fuel pump and the +12 to the coil is connected to the R terminal on the starter.

Make sure the coil has a steady +12 at the + side of the coil, when the ignition switch is on and in start.

Does the choke have any effect, I'm guessing not

Steve

[JOHN COOKSON]

Maybe This Will Help

When I had the problem with the shorted wire from the starter sometimes it seemed like an ignition problem and sometimes like a fuel problem. This made diagnosis somewhat of a challenge especially because it was intermittent.
Here's the part I think you are missing. On my A4 there is a wire that runs from coil+ to one terminal of the OPSS. The other terminal of the OPSS has two cojoined wires - one from the starter that was shorting out and a wire to the fuel pump. When the engine is running or the starter has been turning for awhile the OPSS is closed. Now the circut is coil+ to OPSS through the OPSS to shorted wire to ground. The coil is grounded. With the coil grounded the electricity takes the easy path to ground rather than go through the reistor in the coil. Where's the spark? There isn't any!

TRUE GRIT

[Marian Claire]

Would it make sense to just disconnect all the old wiring and wire a set up as described in the manual for firing a rebuild? Might eliminate a lot of possible problems. Dan S/V Marian Claire