Engine won't restart when Warm

[hanleyclifford]

Just about anywhere. Google "dwell meter". http://www.howacarworks.com/ignition...he-dwell-angle What I find is that people dutifully set the point gap at .018" to .020" (the correct specification), which does not produce a strong spark in a worn distributor. Reduce initially to .015" and see what happens.

[Charrob]

Thank you: we will give this a try!!!

[JOHN COOKSON]

The reluctant starting is not a lack of fuel issue. There will always be enough fuel in the carb bowl from the last run to start and run the engine for ~45 seconds. Hot or cold. You can prove this to yourself. Turn the fuel shut valve off and start the engine cold. It will start then die from lack of fuel. But it will start and run for a short time. Yours is not even starting.

There is one way to prove or disprove the choke theory. When the engine hard starts take the back flame arrestor off and choke the engine by hand by holding your hand over the throat for a 100% choke.

Is the poppet valve on your choke plate and is it working correctly? See page 75

TRUE GRIT

[roadnsky]

Are you CERTAIN that the choke is closing completely?
As John said, take off the Flame Arrestor and verify it's opening fully and closing fully. (See pics)

Here's some good reading info from our guru Don...

http://www.moyermarine.com/faq/11.8.html

As others mentioned a fuel pressure gauge (pictured) would let you know you're getting fuel to the carb too.

Read the attached PDF docs and follow the procedures step by step...

[rconn2]

This is Rob. So, we should be closing the choke when starting warm? I've always believed choke was used for cold starting. In any case, is that the recommendation -- always full choke for the atomic 4 cold or warm?

The engine always starts up right away when cold and fully choked. I've tried choke when warm and it doesn't start. The choke cable is pulled all the way up both times, so I don't know why it'd be completely closed cold and not warm. I can close manually with the lever or hand to be sure.

It's important to know the a4 can't be flooded. I'll put the throttle around 45 and adjust.

I think I'll order the EI and other tune up parts just to eliminate electrical-spark from consideration. My hunch is carb-fuel, but you never know.

[JOHN COOKSON]

Well, No

[INDENT. it seemed the engine wasn't getting fuel as when it finally sputtered after a long crank, i had to give it full throttle to keep it going. ."[/indent]

I think it is just the opposite. You are running rich temporally because fuel is backing up in the carb and cylinders during the no start cranking and a high throttle setting is needed to "unload" the excess fuel.
Next time you have a no start episode pull the center wire out of the distributor cap and hold it near the engine while someone cranks the engine to see if you are getting spark. Report back.

TRUE GRIT

[JOHN COOKSON]

I think I'll order the EI and other tune up parts just to eliminate electrical-spark from consideration. My hunch is carb-fuel, but you never know.

An EI will not end engine ignition problems if there is a problem with the boat's wiring.
I strongly recommend that you get the current problem solved with the current ignition set up before making any changes.

TRUE GRIT

[nreeves]

I have the same issue that just started this season. It starts fine cold, runs fine, then stops suddenly once warm. Once warm, it is also very difficult to restart. It will turn over, but not start without choke and lots of throttle. I do close off the water intake when trying to turn over.

I am trouble shooting today and have done the following so far:
- checked compression - good on all 4
- checked spark
- Checked fuel air line - clear
- About to check fuel line, filter etc & pump. I set a manual prime and can set that. I am testing if a manual prime corrects the issue to see if it is part of the problem.

Any other ideas??? Could it be the t-stat? I take it out every year in the winterizing process and this is the first year I did not boil it to test it. Could this cause a stall?

Help

[Marian Claire]

nreeves
" It starts fine cold, runs fine, then stops suddenly once warm."
Makes me think coil issue. Have you checked for spark immediately after it shuts down? Lots of info on the forum about heat induced coil failure causing sudden shut down.
Dan S/V Marian Claire

[JOHN COOKSON]

nreeves
Maybe a blocked fuel tank vent. To check loosen the fuel fill cap.
Does the engine sputter like it is running out of fuel or suddenly quit like somebody turned off the key?

TRUE GRIT

Edit: Do you run points or EI? (electronic ignition)

[nreeves]

nreeves
Maybe a blocked fuel tank vent. To check loosen the fuel fill cap.
Does the engine sputter like it is running out of fuel or suddenly quit like somebody turned off the key?

TRUE GRIT

Edit: Do you run points or EI? (electronic ignition)

Tried that and there is no block. It is looking like it may be the coil. I checked the rest of the fuel system and it seems to be working fine.

[rconn2]

Thanks for your suggestions. I'll hold off on a new ignition system. I agree... it'd be best to figure out the issue first and not complicate things further.

I'll troubleshoot this weekend and post back.

[smosher]

Ah New fuel lines. I replaced all of my fuel lines as they were old. My first time out I had a problem after running for several hours
the engine quit and wouldn't restart. I have the facet fuel pump.
What I found was one of my hose barbs was 1/4" instead of 5/16 and
I had an air leak. Replaced the hose barb and the problem went away.
The facet doesn't pump very well with a air leak.
I added a fuel pressure gauge.

Steve

[rconn2]

An updraft carb, like the one on the A4, is almost impossible to flood and will need brief full choke to start when fully warmed up. More choke will be necessary to start a cold engine.
Have you been using the choke to start when the engine is warmed up?
Try with ~45* throttle setting when starting a hot or cold engine then adjust from there.TRUE GRIT

That worked! At least it worked after the engine ran at the dock for around 20 minutes. I stopped the engine. I pulled up for full choke and slowly released the choke _while_ cranking the engine. And, the engine started as the choke was mostly released -- but it seemed to need the choke at the beginning of the crank... even though I heard no sputter in the beginning.

I tried without choke, and after several cranks, the engine wouldn't start. Then, with choke, as described, and it started. I tried this comparison a few times, and it always started with the choke -- and, on the first crank -- and never without the choke.

So, this is the trick with this carb and engine? Thanks so much for pointing this out. It's important to have confidence that your engine will start when needed.

-- Rob

[67c&ccorv]

That worked! At least it worked after the engine ran at the dock for around 20 minutes. I stopped the engine. I pulled up for full choke and slowly released the choke _while_ cranking the engine. And, the engine started as the choke was mostly released -- but it seemed to need the choke at the beginning of the crank... even though I heard no sputter in the beginning.

I tried without choke, and after several cranks, the engine wouldn't start. Then, with choke, as described, and it started. I tried this comparison a few times, and it always started with the choke -- and, on the first crank -- and never without the choke.

So, this is the trick with this carb and engine? Thanks so much for pointing this out. It's important to have confidence that your engine will start when needed.

-- Rob

The necessity to use full choke is described in the manual...do yourself a favor and get one.

It's a characteristic of the updraft carb.