Engine runs fine and dies after 10-15 minutes

[jimlyon]

Hi everyone,
I have tried to read as much as possible on this prior to posting. If I missed a post with the solution to this, please forgive me.
Our late model 73 Pearson 30 - atomic 4 shuts down after running 10-15 minutes. This is our first season owning the boat. First trip from the boatyard to our slip the engine died gradually over 2-3 minutes and would not re-start. Increasing throttle had no effect. It would then not re-start even after sitting for days. Subsequently we did the following before it would start again:

Fuel system:
drain the fuel tank, remove and inspect the pickup tube. There was a little water in the gas, 10 gal had been sitting for 3 years. It has a Monel tank and we cant pickup any debris sticking things down the fill tube. Reinstall with new fuel line with priming bulb to a new Racor fuel filter. Rebuild the carb with Moyer's kit. Remove and inspect the fuel pump. (The fuel pump pushes fuel and the manual lever works. Install in-line clear fuel filter even though it doesnt meet CG specs, to catch any crap that might come from the fuel pump.
Electrical:
Install electronic ignition and rebuilt alternator which we fried by turning the main switch off while running. Replace coil twice after over-torquing the terminal on the first one. Replace spark plugs but not wires as they look newer.
Replace main shutoff switch that broke during the process. Replace cracked resistor (over-torquing again).
We can start the engine it runs smooth but it dies after 10-15 minutes, now it dies over 3-5 seconds instead on a few minutes.
We have OK compression except one cylinder is 85psi, we plan on pulling and rebuilding the engine this winter anyway but it would be nice to get a sail in before then.
After the engine dies and we cant restart, it will restart after sitting for several hours, although we havnt nailed down the time interval before it will restart. There is no fuel in the carb intake area at this point with the spark arrestor removed, and the cylinders dont appear to have any accumulation either.
Seems like its not getting fuel but the why has us stumped.

Jim

[ndutton]

Two Thoughts

Thought 1
Maybe a stuck float valve. Try tapping the carb, well maybe half way between a tap and a smack, with the handle end of a screwdriver while it's cranking and not starting (this gets the added help of fuel pressure). If the valve is stuck, that may open it up to transport fuel. It'll take a little more cranking to fill the float bowl. If it works, it's an indicator rather than a solution. There's an additional concern if your raw water intake is open during these prolonged cranking episodes, potentially overfilling the waterlift, backwashing into the exhaust and into the engine.

Thought 2
You said you added electronic ignition, replaced 2 coils and a ballast resistor. I'm wondering why you still have a ballast resistor if you replaced the coil. What coil do you currently have? What's it's internal resistance? What's the impedance of the ballast resistor? I'm not convinced your setup is a problem but the conventional wisdom around here is when upgrading to electronic ignition, replace the coil with one of 3 ohm internal resistance and no external resistor. The Pertronix Flamethrower #40511 is frequently mentioned.

[jimlyon]

Thanks Neil, it would be unbelievably fantastic if it was a stuck float. I will try this tomorrow.
As far as the coil, we got it at West marine, I will check the specs and post back.
Jim

[smosher]

try a little gas into the throat of the carb and see if it fires.
Besides the stuck float you could also have an air leak or a defective fuel pump

I added a gas pressure gauge to my p30 # 574, a quick glance and you
know the fuel is getting to the carb.

Any auto parts store will have 3.0 ohm coils on the shelf and you do not need a ballast resistor

Why are you pulling the engine ?

Steve

[jimlyon]

Hi Steve, thanks. We are thinking of rebuilding the engine because the compression in one cylinder is 80-85, and 110 in the others. I have a buddy with a shop and the skills and experience. His rate is about 6 bottles of single malt scotch, he likes Glenmorangie, Balvanie, JW blue. The good news is I get to help him drink it.

[ndutton]

Sometimes Bigger Isn't Better

Any auto parts store will have 3.0 ohm coils on the shelf

Yeah, any REAL auto parts store. When I went looking for mine I tried Auto Zone (it was on the way to the marina). Told the teenager on the counter what I needed and stepping up to his computer, asked "What car is it for?" Not for a car, so I repeated that I needed a 3 ohm primary resistance coil, preferably a Pertronix Flamethrower #40511 or equal. "Unless you tell me what car it's for I can't access the system." Thanx alot, adios muchacho!

Down the street I walked into Checker/Schucks/Kragen. 3 ohm primary resistance coil please, preferably a Pertronix Flamethrower #40511. "What car is this for?" Great, SEE YA!!

Gave up on those parts "boutiques" and finally gave Baum's Auto Parts a call (Mission Viejo, California). Baum's is a real parts store, Bob Baum himself works the counter, answers the phone and has done his share of wrenching. He has only one store but it's for real. I told him what I needed, he said he didn't have it on the shelf but could order it. I said fine, please call me when it's in. That call came 30 minutes later, ready to pick up.

[hanleyclifford]

Now that we are living in the era of auto parts "boutiques", I have established a protocol on my boat whereby each time I purchase a part I record its brand and number in a permanent area in my log to include cross referencing because we never know which "boutique" we might have to depend on while on the road. I am also considering language cross referencing - who knows what's next?

[thatch]

"parts check"

jimlyon,
Several years ago I had an engine shutdown situation similar to yours. The problem turned out to be the plug wires. As it turns out the "Pertronix II" ignition module needed "suppression core" wires instead of the solid core wires I had. With the solid core wires the engine would start, run for several seconds and then shut down. New S.C. wires solved the problem.
Tom

[tenders]

I keep a running list of all my A4 parts, sources, and costs in an address entry called "Atomic Four" in my Blackberry.

It includes:

Fuel filter, polishing filter, spark plugs, distributor cap, rotor, coil, plug wires, water pump impeller, belt (for both old 35A and new 120A alternators), carb, coolant fan switch, head gasket set, head stud torque, oil pressure switch, water pump grease, electronic ignition module, and (obsolete with electronic ignition) points, gap, and condenser.

I have similar entries for the boat (which includes registration numbers, draft/length/displacement, sail numbers, bulb sizes, battery sizes and installation dates, waxes, paint colors), each of my cars (VIN, plates, wiper blade and filter sizes, etc), and my computer printers (model number, replacement toner and drum types).

[jimlyon]

Hanley and Tenders, thanks for the suggestion about recordkeeping, it seems obvious and we will start this now. Easy to do at the time of purchase.

Thatch, I also wondered about the ignition wires, I didnt know there could be a variable effect like this or that special wires were required for electronic ignition? Thanks for the suggestion, I think its worth replacing the wires in any case at this point.

Jim

[jimlyon]

Progress

Well the engine ran no problem today for 20 minutes before we had to shut it off to leave.
We narrowed our focus to the carb based on advice above, even though we had rebuilt it several weeks ago. We took it apart and discovered a greasy coating on many of the internal surfaces. We couldnt believe how it looked, it was spotless when we rebuilt it. Disassembled and cleaned everything, reassembled, and flushed 2 qts of fuel through the carb. The color of the fuel changed from brownish to normal looking. Engine started and ran 20 minutes no problem. We are ordering a fuel pump rebuild kit as we suspect a lot of this "varnish" deposit came from the fuel pump.

The state of the fuel tank is an unknown at this point, we dont know if additional varnish dissolved by the new gas (with ethanol) will be moving from the tank downstream to cause this problem again-? Or will our fuel filters intercept the dissolved varnish? We do have a Monel tank, at least rust debris isnt an issue. Anyone have a similar experience with gunk in the fuel?

Many thanks also to Don Moyer for his advice outside this forum.

Jim

[smosher]

I usually goto napa and give them the napa numbers.

I did goto autozone and asked for a 3.0 ohm coil and they had it in stock.

[ndutton]

I did goto autozone and asked for a 3.0 ohm coil and they had it in stock.

I have little doubt the local Auto Zone had it in stock. The aggravation was the reluctance of the clerk to actually walk down the aisle to take a look. I bet he could've found the racing stripe tape and flame decals without knowing what car it was for.

Glad for your Auto Zone experience but for mine, a big 'We're #1' (gestured) salute!!