Engine stops after 5 minutes or so

[seapadrik]

Hey everyone,

So after reading tons of threads on coils, timing, idle mixture jets, idle speed screws, float valves, running rich, running lean and the like I still need to ask a few questions.

Problem statement:
After starting engine

- with full choke
- with timing set initially using the Continuity light / TDC method in Don's literature/videos. I haven't got to a point for adjustments at high RPMS yet.
- With a rebuilt carb
- With new spark plugs
- With idle mixture screw at 1.5 turns out in lean direction
- With a new Gas tank, new fuel lines, new fuel filter throughout the system

The engine just stops around 5 minutes or so. This is after I have turned off the choke and am just idling.

NOTE: It does not sputter in any way or die a painful death it just ceases to run. This manner of engine death also happened before I rebuilt the carb and I naturally assumed it was a blockage. Still might be, but who knows.

If I attempt to restart it it will usually restart immediately. And I can go for another few minutes. I just cant ever just idle for say about 20-30 minutes that I want to so I can fine tune things and set idle under load at the dock.

Further details:
-Facet Electric fuel pump purchased from MM
-FlameThrower Coil with 3 ohm resistance ( no ballast resistor as of now )
-Seems to be a light sheen on the water that looks like maybe fuel, but not so much the EPA is after me.
-Rebuilt Exhaust Riser, clean as a whistle
-Plugs are a little black and partially sooty, definitely not TAN as some people describe but I wouldn't really call them dripping wet either.
-I do not have inline mechanical pressure gauge although I intend to get one installed pronto
- I do not have a TACH

Thoughts ?

Any tips are highly appreciated. I am so close I want to run this engine ASAP.

thanks

[edwardc]

This sounds very much like the situation I had about 3 years ago. Mine was caused by a failing Facett pump. The check valve ball inside the pump was sticking to the seat, causing a vastly reduced flow volume through the pump. It simply couldn't keep up with the engine's needs and the float bowl would run dry in a few minutes.

Opening the bottom of the pump and pressing on the stuck ball freed it and solved the problem, but it was only temporary, as after a few days the ball stuck again.

The only permanant fix was to replace the pump. It's been running fine since.

[JOHN COOKSON]

Originally Posted by seapadrik

NOTE: It does not sputter in any way or die a painful death it just ceases to run. This manner of engine death also happened before I rebuilt the carb and I naturally assumed it was a blockage. Still might be, but who knows.

The sudden shut down, like turning the key or switch off, suggests something electrical or ignition related. It is by no means conclusive however.
You could start by running a wire from the big cable on the back of the starter to coil + and see if the shut downs go away. Do not leave this wire connected and hot when the points or EI is closed for more than a minute or so or the coil will be fried.
If you have an EI maybe it's acting up.
Others will have other ideas.

TRUE GRIT

[romantic comedy]

I had an intermittent fuel pump, and it was a pain to trouble shoot.

First thing I would do, would be to hook up a separate gravity feed fuel tank. A gallon jug with a hose might do just fine. That eliminates the fuel pump and filters.

[CalebD]

Could also be a faulty OPSS.
Even new ones have been known to fail shortly after startup with similar symptoms.
Just ask jacques debauche:
http://www.moyermarine.com/forums/showthread.php?t=5270

[hanleyclifford]

Are you running electronic ignition?

[seapadrik]

Hey everyone,

Thanks for your comments and insight. I have an update. I went down to the boat with 3 things in hand with the intention to replace and observe as a strategy. I figure if a part isn't needed at the moment it will enter the rotation as a backup.

So at the boat I brought 1 new coil ( 3 ohm Napa one that has been discussed on this site ), 1 new OPSS rated at 10 psi, and 1 new facet electric fuel pump.

The order of replacement was as follows:

1. OPSS - no change, engine still died after about 3-5 minutes. This time I noticed that it started up immediately after the engine shutdown which made me think it was not a fuel issue after all. With that in mind I decided to do coil next.

2. Coil - Here is where it gets weird. I went to remove the old coil from the engine where its strapped on, and despite it having no wires to it at all since I had just removed them, I got Shocked when grabbing that coil from the engine. I imagine i touched both the engine block and the coil but its a mystery to me why I go shocked, but it hurt for sure.
I then decided to use my rubber insulated pliers to remove coil and it came off no problem. I honestly cant remember if I had the battery switch on at this point.

I installed the new coil and started it up. Not only did it make it past 4 minutes I easily made it to the 25 minute mark ! Accomplished alot of adjustments to idle under load, etc... Although I didn't mess with distributor ... just trying to get an acceptable idle speed under load. I turned the engine off an it sounded great no backfire or any such thing. Nice to be the one turning the engine off more a change.

At this point I am quite pleased with myself and other than the Shock I experienced. Well as it turns out I solved one problem to move on to yet another ...... Of course ...

I noticed that the OPSS ( the new one ) would allow the Electric Fuel pump to click on ...... even when the ignition switch was in the accessory position. I know for a fact the old OPSS only allowed Fuel pump to click on when the engine was being turned over and the engine runs. Now this thing is on full time when ignition in accessory. Hey with that feature priming is a breeze Not right of course , but I was still happy the engine was running.

So now with the engine off I went to turn on the BLOWER and it won't work !
I couldn't understand , but hey I need my blower so I found an extra 5 amp fuse and replaced it in my blue sea fused busbar for the blower. Indeed it started right back up and blower worked. But I had one more fear and that is with both the engine running and the blower running together. The engine runs like a champ. But the blower switch, you guessed it. Blown again !

Then it got dark and I decided to call it a day. Where I am at now:

- My engine starts and runs brilliantly for a very long time
- I got shocked by an old coil with no wires attached to it
- I have a new coil installed
- I have a new OPSS installed
- My blower and engine can suddenly not run at the same time together without blowing out blower.
- My OPSS allows fuel to click pump on when the ignition accessory is turned on. I assume this is messed up, unless that is way its supposed be and I've been wrong about this switch.

NOTES about my wiring:
All new wiring harness, but I guess that doesn't mean anything. No tach, no ammeter, 4 gauge wire from alternator to starter lug, common lug on perko to starter, positive coil to OPSS, OPSS to 5 amp fuse to Elec Fuel Pump.

The blower has its own wiring and fuse. Can't understand the relationship to that thing blowing the fuse when the engine running. They coincided peacefully before any of this.

Thoughts ? I do have a multimeter but am just learning to use it. Is my engine block energized ? Help ? What about that 5 amp fuse between OPSS and Fuel pump is that playing a role ?


PS- I do have electronic ignition for those who asked

Thanks

[ndutton]

Blower fuse
For starters the fuse is too small. Assuming you have the typical Jabsco snail shaped blower, even the smallest one draws 4.4 amps @ 12V. Throw in alternator output voltage and a new, clean harness and you could easily be over 5 amps. I'd bump the fuse to 7.5 amps and go to a slo-blo type.

Fuel pump runs on accessory key position
You have a wiring problem. There's no way I can tell you where, time to start tracing wires.

New 3Ω coil
You clearly had a coil problem before but there's a good chance you'll have one again. I did not read where you went through the coil resistance analysis necessary with electronic ignition. Until you do your new coil is at risk. The Cliff Notes version is here, post #20.

Shock from the old coil even with wires disconnected
That's a new one. I can't begin to explain why except that coiled wire of any sort has the ability to store a charge.

[seapadrik]

Update and some good news

You were spot on with reccomendation of 7.5 fuse. I can now run blower with engine running

The "wiring problem" with OPSS was me not paying close attention when I bought it. I bought and installed a sensor for oil pressure alarm system whose default switch is off. It turns on alarm any time engine below 10 psi. Thus the reason it was on when ignition accessory
. I threw it in tool box as a backup primer device if ever needed.

Finally my resistance is 3.7 ohms. I couldn't get reliable volt readings. May need alligator clip for that

Will update more tomorrow. I also bought a Napa resistor 0.88 ohm as precaution altghough I am unsure where to install it I thought it would clip on coil but this looks strange to me
Thanks everyone

[ndutton]

Does your resistor look anything like this?


It installs in series with the coil. I prefer the '+' side but the '-' side works well too. Whichever side you choose, remove the wires from the respective coil post and connect them to the resistor. Connect the other side of the resistor back to the coil post. Done.

When mounting the resistor consider that it gets hot normally, that's why it's made of ceramic. The mount should be able to handle the heat. A nylon ty-wrap strikes me as risky. Maybe even cheesy.

I'd install the resistor right away as the precaution you mentioned. We can follow up with the voltage measurement when it becomes available but with your new harness it's reasonable to expect the voltage to be over 14. Why not protect the coil in the meantime? Be sure to to a start and run test immediately after installation. Before and after temperature gun readings are a plus but not essential.

[roadnsky]

Originally Posted by ndutton

When mounting the resistor consider that it gets hot normally, that's why it's made of ceramic. The mount should be able to handle the heat. A nylon ty-wrap strikes me as risky. Maybe even cheesy

I found that the bolt for the hold-down bracket for the coil fit nicely thru the hole in the resistor and made for a firm mounting.
And... YES ... it does get HOT!

[Nick duBois]

Originally Posted by seapadrik

So at the boat I brought 1 new coil ( 3 ohm Napa one that has been discussed on this site )

H Sepadrik,

Do you have the part number of the coil you bought from Napa? Is it an IC14?

Nick

[seapadrik]

Yes the coil I purchased is ic14 model

And the resistor I purchased looks exactly as in photos.

I will mount it on same bracket as others have done

So to make sure I understand wiring. Is it as follows.

Ignion wire from my wiring harness > one side of resistor > other side of resistor > positive side of coilis that correct?

Thanks

[ndutton]

Originally Posted by seapadrik

So to make sure I understand wiring. Is it as follows:
Ignition wire from my wiring harness > one side of resistor > other side of resistor > positive side of coil. Is that correct?

Correct. Be sure your wires don't rub on anything sharp or hot.