Perplexing engine dying problem

[rpowers]

Hello friends,

I am just about at my wits ends with this one...

Symptom: Engine runs great for 40 minutes, then sputters and dies.

This is reproducible; it stops at the same location every time I go out.

What I have done:

1) Drained and cleaned the fuel tank, re-filled with new gas.

2) Replaced fuels filters, both Racor and polishing.

3) Checked Facet fuel pump. It seems to be pumping gas OK.

4) Adjusted oil pressure. It had been dropping too low so I turned the adjusting screw inwards and now have a minimum 20 psi.

After all that, it still does the exact same symptom. 40 minutes of running great, then a sputtering death. Sounds like fuel starvation, with dying surges until stopping.

What to do next?

1) Disassemble the Facet fuel pump to look for a problem there. Anybody ever done that?

2) Could it be the carburetor? It starts easily and runs great until 40 minutes of run time.

I would really welcome any suggestions at this point.

Thanks!

[tenders]

1-fuel supply-install a squeeze bulb between the fuel tank and the fuel filter. If when sputtering squeezing the bulb helps, there's a fuel supply problem downstream (or a clog upstream)

2-spark-old coils can fail as you describe once they get hot, although usually the engine just dies suddenly

[sastanley]

Did you replace the coil yet? I didn't see that in your list.

My coil worked admirably for 60-70 minutes and then it shut off...like fuel starvation..which was the kicker (the fuel starvation sound, except when I pumped my squeezy bulb it still died, but isn't wasn't quite the turn-the-key-off-died sound you'd expect from a failed electrical component like a coil).

Other possibilities could be a bad electrical connection that works OK when cold and then as it heats up, creates an open.

Edit - after reading Mark's question and in hindsight, he is right. I tried to check for spark at 1:00 PM in the afternoon..but it was inconclusive & we were drifting around in the river with no way on...not a real good visual indicator with the sunshine so high & the wife embarrassed that our engine had quit...

[Mark Millbauer]

When it quits have you checked for spark? Sounds like it may be the ignition coil heating up but could be a number of ignition related issues.

Mark

[Dave Neptune]

40 minutes?

Do you know you have fuel preassure, I mean with a guage or a squeeze buob? Usually if a coil is going bad it will shut off when it expands after heating and works when it contracts after cooling allowing the break to racontact. They seldom stumble and sputter as a fuel problem usually does.

Get it to fail then pull the coil wire and crank so you can observe a spark or not. You can get a cheap preassure guage for under 20 bucks and plumb it in just before the carb.

It could be that your vent is plugged up and it takes "just so long" for it to slow fuel flow causing a slow dying of the engine.

Dave Neptune

[rheaton]

Don put together a nice doc on sudden shutdowns. Take a look for it on this site. When I had this problem, I ended up installing installing a fuel filtering system, and replacing my ignition wiring. Best of luck. Take care, Russ

[breweraz]

similar problems

I had a very similar problem. I was convinced of a gas problem but after reading the post changed to electrical and coil. It was also easier.

When the motor will not start, pull the lead wire off the coil, hold it about a 1/4 inch from the top of the coil and try turning the motor over. You should be able to arc a sparc. If no spark than I sugest the following. If you have a spark go the fuel route as suggested in the other posts.

There are three things I ended up replacing, but in my case, one at a time so it was frustrating. If I ever have the problem again it will be all three.

Assuming you have a points system:

1 . Replace the coil - if you go to a parts store, as opposed to ordering through Moyer make sure you look closely at the specs. The coil must be a 3 ohm resitantce or more. There is a popular coil used in older tractors that looks very similar. The parts store guy looked at my coil, grab one off the shelf and told me 'this was it" . It looked similar but was only a 1.5 resistance. That coil will run for a little while, heat up and stall the engine proably burn out more if I tried to run it any longer.

2. Replace the condenser. These are cheap and very easy to replace. I am not an electrician but generally when one item in the chain fails it loads another and failure is not far around the corner. When the coil is going bad it ususlly only runs till hot ssputters just like a gas problem and in my case quickly got worst, to the point she will not start at all. But since each condition and motor is different there are no absolutes.

3. Check all your wires off the coil especialy the wire from the neagtive terminal of the coil to the distributor. In my case the wire from the coil to the distributor looked good from the outside but at the connector was broken down to the last few strands.

After getting the right coil, back to the store for a condenser and the last run to get the right connectors, she has run great. None of these parts are difficult to change and not very expensive. So go for it all at once and save yourself some grief. I now carry replacements of all three on board and since I have them now I am sure I will not need them so says some rules of fate.

I know the frustrating feeling when you do not have confidence in the motor. But I can tell you when the A4 is dialed in it is a great motor.

Tim

[rpowers]

FIXED ! Found the problem

Ok, so here's what I did:

I have a second small in-line electric pump that works at the same time as the Facet pump.

So I took the Facet pump out of the system. Everything worked great!

Then I trouble-shot the Facet pump off the engine.

It was clean inside. Filter was good, and the ball valve was good.

12V tested it, and it pumped fine off the engine.

Then re-installed it on the engine, and bypassed the oil pressure switch, and it didn't work!

I had 12V coming out of the coil, but not getting to the Facet pump.

I opened the fuse holder, and guess what? BURNED FUSE

Problem solved. The first smaller pump was able to pump enough through the dead Facet pump to run for a while, then fuel supply failed after 40 min, and engine died.

I like these kind of solutions!

[tenders]

You've answered one question but raised two.

1-what burned out the fuse? shouldn't ever happen. the fuse is an indication of an event that you should get to the bottom of. is the insulation chafed off of an electrical wire someplace? or did you ground something momentarily and accidentally while working on the engine?

2-why did somebody decide the installation needed two fuel pumps? you've just proven that they aren't redundant!

[roadnsky]

One additional question to those posed by TENDERS...

What SIZE and KIND is the fuse?


PS - Congrats for finding what I'm sure was a frustrating issue.

[hanleyclifford]

This reminds me of one of MY favorite procedures - overlooking the obvious!

[rpowers]

Fuse Burned Out

Ok, I forgot to mention that a while ago I did (another) stupid thing.

I left the boat with the ignition "on". I burned out the electronic points (I mean really burned!). Replaced it, then went on with my life.

I never thought to check further, including this fuse.

Not sure that burning points would burn this 5 amp fuse from coil to pump, but it seems possible.

Regarding the dual fuel pumps, when installed the new Facet pump, i couldn't think of any good reason to remove the first (perfectly good) in-line pump. Now I know that I can use either one in a pinch!

Again, thanks friends for listening in. I'm getting better at this!

[roadnsky]

Just a suggestion...

You'd have less head loss (and failure points) by only having ONE Fuel Pump in line.
You can have the 2nd one IN YOUR SPARES KIT, for a BU.
Having 2 fuel pumps isn't an advantage, it's a liability.

Just my opinion...

(In any case, congrats. It's always a great feeling to solve issues after a long hunt)

[Dave Neptune]

Suggestions

rpowers, what Jerry said is a great idea. A spare that works is better than wearing both out for no reason. I have a mechanical pump and a spare electric one with pig-tails attached in my "get me home box".
While removing the extra pump would be a good time to install a cheap fuel preassure guage, then all you have to do is look at the guage!

Dave Neptune

[Dave Neptune]

Suggestions part II or oops!

Sorry forgot to add that it could have been the voltage drop that caused the fuse to burn, as voltage decreases amps go up.

Dave Neptune