Engine dies

[cdisney]

I have a gas atomic 4 in a 82 Cat 27. For the last couple months the motor dies at about the same time almost every time I go out. I motor at about 3k from my house out the channel and then take it up to 5+K and it dies within 100 to 300 yards. It starts right up without any problem and then may die one or 2 more times in the next couple minitues and then run fine for the next 45 min to hour and a half. I have replaced fuel filters, elect fuel pump and carb and the problem is still the same. I have also put on a sueeze bulb to presurise and check for air leak but seems fine.

ANY SUGESTIONS OR HELP WOULD NE MOST APPRECIATED

CHRIS
South Lake Tahoe, Calif

[rewell6]

Doesn't sound electrical unless a wire is getting pulled until the restarts.

Check the choke and make sure it isn't sticking. After throttling up and down while restarting it might be coming unstuck and allowing it to run.

Fuel, air, spark. That simple.

Don't forget to make sure the flame arrestor is clean.

[cardiacpaul]

wander into your local autoparts store...

Ask for an internally ballasted 12 volt coil. Spend no more than 25.00. If they demand an application, smile sweetly and say for an Atomic-4. When their eyes return to focus, say... "something from a mid '60' or 70's chevy"

Return to boat, coil in hand. Remove coil from A4, along with the ballast if so equipped ~(either a ceramic looking thingy about 3 inches long, or a curled like a telephone cord type of wire that attaches to the coil. feel free to cuss like a sailor at this point), replace ballast or wire with 12 guage stranded copper wire (oh, geez, tinned,crimped, superglued, varnished, cut by a virgin, marinized, marinated, frozen to -86.39 blah, blah, blah ~ tongue firmly in cheek) tighten the clamp and all nuts, and fire that mutha up. You'll be fine.

If you get a wild hair sideways, now might be a good time to replace the distributor cap and rotor too.

Standard interchange part numbers...

Dirstributor Cap
Delco D322R
GM 1962446
GP DR93
Echlin RR181

Rotor
Delco 423R
GM 800056
Borg Warner D152P
Echlin RR182R

If you're feeling like Smoky Yunick Or Keith Black while replacing the cap & rotor, you can bribe one of your lady friends out of one of her paper nail files and run them thru the points a couple of times, just to clean them up.

[cdisney]

Still looking for HELP!
The boat has Indigo electonic ignition and a New coil. I have also ran a jumper wire from positive on battery to th e electric fuel pump, a jumper from positive on battery to positive on coil and it still dies. I have also used a remote fuel tank directly to the fuel pump. The way it dies after 15-20 min, may die 1-3 more times in next 5 min, each time restarting immeditaley and then runs fine for next 40 min the hour and half I woundering if it could be heat related some way. Although the tempeture gauge doesn't show over 120..

[Stillraining]

FWIW ....I'v had to replace my electronic module in my motorhome twice in 2 years. in my case I think it is due to heat but cant be certain of that

Too funny Paul..

(oh, geez, tinned,crimped, superglued, varnished, cut by a virgin, marinized, marinated, frozen to -86.39 blah, blah, blah ~

[cardiacpaul]

your electronic ign. module (in the distributor) is shot. Yes, its heat related.
Theres no airflow there, temp is WAY above 150 in there. call indigo & get a new one.

[hellosailor]

I would also suspect heat and " Although the tempeture gauge doesn't show over 120.." that's just too cold even for a raw-water cooled engine.

The way that it dies after warming up a little, and then runs fine once it is thoroughly heated up, makes me think "choke". That's the only thing that is changing with the warmup process, choke setting and a change in the carb from "cold start" to "main" operation.

Something like a bad coil or fuel supply would tend to simply fail as it heated up--and stay failed, AFAIK.

I don't have any faith in any "rebuilt" carb, because rebuilding one properly takes time and attention, and most shops mess up something because they are trying to rush the job. I'd start by taking the carb and choke, breaking it down and rebuilding it literally "by the book", and making sure the choke parts were working correctly. If there's a vacuum diaphragm or something similar--check that for leaks and proper operation. Could also be the carb is not seated properly, and the changing heat is opening up a tiny vacuum leak between the carb and engine, then shifting to close it again, so don't assume anything, check that gasket & fit for vacuum leaks as well.

Be glad it is an A4, working on fuel injection systems can be much much harder.

[riphonda]

My A4 is particularly susceptible to water in the fuel tank. I had a bear of a time getting the baby up and running even when there was miniscule amounts of water getting in the carb. It would start and idle, but as I would leave the harbor it would soon die, then start at random and continue to run again. Prob solved when i switched to a remote 6 gallon outboard style tank with fresh fuel. Maybe check the fuel bowl just before the carb and pour into a glass jar to make sure no water in fuel... then maybe a racor or other fuel water separator? Best of luck. These engines are simple but boy do they seem to have alot of gremlins. Start with the simple stuff ;o)

[cdisney]

Thanks for the input. But I hope I have solved the problem, after checking all other possibilities I concluded it had somthing to do with fuel starvation.
I had added fuel line when putting on a squeese bulb to prime system and also added extra fuel line when putting on second fuel filter. Also had a couple dips in the fuel line because of extra hose.
So I took off squesee bulb and extra line and it has only died once out off 14 times out. So I hope the problem is solved. Will see next spring since the snow is near.

[Kiskadee]

I'm sure you're correct to believe it is a fuel problem. Heat or RPM related problems with any part of the ignition would either cause a lack of power at higher RPM or not allow it to restart so quickly.

A big question is how an engine sounds when it stalls. Did it stall instantly or did it stumble a bit while stalling? If it ran out of fuel it may taken between half a second and three seconds to stall. If it's electrical or electronic it may have stalled instantly.

Your problem sounds like the carb isn't getting enough fuel in the float bowls. When you ask for increased RPM it uses up the fuel from the bowl faster than it can refill. This could be due to a few things.
-A restriction in the fuel line: Check for kinks in the rubber line or dirt in the tank pickup tube. You should be able to blow fuel back into the tank without excessive resistance. (But your problem persisted with the aux tank.)
-Weak fuel pump: Although new, the pump may not be working correctly. The engine should run from the aux tank with the fuel pump bypassed, if the tank is two or three feet higher than the carb.
-Wrong fuel pump: The A4 only needs about 2 psi fuel pressure. There are two electronic pumps available at Moyer Marine. If the engine is below the tank use the 2-3 psi model and if the tank is well below the engine use the 3-4 psi model. Some Catalina's need 3-4 PSI. Insufficient pressure would not allow it to hold high revs.
-Incorrectly adjusted carb floats: If the floats are set too low they will close the needle valve early with the float bowl only partially full. This is easy to set. Split the carb in half (4 screws) and turn it upside down. The floats should sit parallel to the carb body.
-Blockage inside the carb: There is a small chamber between the carb's fuel hose fitting and the top of the needle valve seat. If dirty it may restrict the flow of fuel. Too much teflon tape on a fitting may be stuck on top of the float valve seat.
-Wrong type of hose: Make sure every inch of rubber hose is rated for gasoline and is CG approved. Some rubber breaks down in gasoline and swells up, restricting flow. I've seen this screw up a motorcycle when the owner used vacuum hose as fuel line.

This past summer my fuel pump died and I ran for several hours with a jerry can in the cockpit and just gravity feed to the engine. Good luck with your A4, which is still one of the best little engines made.