engine idling fine then shut off like turning key off, will not restart
 

For long tome forum folks, thanks for the years of advice and help. Happily, I finally got my A4 running great, two days ago. The surging issue resolved itself, magically, and the engine was running perfectly. Two days ago. Today, after repairing the genoa went down, put the sail back up and went to start the engine. A little cranky but it started and was idling at the slip just fine. Started casting off lines and poof, engine just went dead, just like I had turned it off. Trying to restart met with zero success, even with ether, nothing, so I am thinking ignition, not fuel. Checked spark at plugs and it seemed weak, checked spark from coil wire and altho a bit stronger still seemed weak. Tried cleaning and resetting the coil wire, nothing. The engine makes zero effort to start. The coil is virtually brand new after replacing late last year (thanks for the advice on that). Electronic ignition. New carb, fuel line, and tank (the root cause of many problems, a totally rusted tank). This is just infuriating, the engine was running better than it ever had just 2 days ago. Appreciate your thoughts.

I am presently working through the exact same issue! My A4 now starts perfectly every time, however, will stop after a short time....and I too have done all the stuff that you outline...new filters, draining the carb, new plugs, new coil. My next step is to dismantle and clean the carb completely. However, in your case, if you have an electric fuel pump, the oil pressure switch could be bad....which prevents the pump from delivering fuel! Make up a short jumper wire, and bypass the switch.....if it starts and runs, you have found the problem...Good luck!

All the times my engine died at idle happen to have been due to a closed fuel valve (several ¡a-ha! moments resulted). Assuming that’s not The situation here, there’s no harm in taking five minutes to remove the cap and making sure the rotor is intact, positioned properly, and that the contacts are cleaned. Does your new fuel system have both spin and polishing filters in place, and has the fuel been stabilized? (If not, your nice new carb could be gummed up already.) Are you sure your OPSS is connected, or bypassed for this situation, and do you have fuel pressure (add the $20 inline gauge)? Is your coil of the proper resistance (helps if sourced from Moyer)?

Do the cylinders smell of raw unburned fuel after starting attempts?
What is the voltage at coil + when the key is in the on position?
Have you been keeping the raw water intake valve closed during the no start cranking?

TRUE GRIT

John did not notice a strong fuel smell when I pulled the plugs to test spark, but frankly did not do a sniff test. Will check voltage next trip to the boat. AS for raw water intake, no, but I confine my start efforts to relatively short bursts to avoid pumping the engine full of water.

Thanks for the idea. It sounds like my fuel pump is working, and I am really pretty positive it is not fuel related. I am just coming off a 2 year fuel related nightmare so everything in the entire system is new, including the carb, which I actually took apart and cleaned at the start of the season. I will try the jumper tho.

Thanks, Tenders. No, fuel valve is open (this time, been there, done that..) I am suspecting something with the distributor, electronic ignition system, wires or distributor cap. My cap is "funky". Think I might try new wires, plugs and cap. Ignition system overall is my personal mechanic weak spot. What do you think?

Wow, i wish I had picked up on yoiur idea of oil pressure switch originally. In pouring thru the Moyer manual the oil pressure switch caught my eye as a possible problem. I am replacing dist cap, plug and coil wires, new plugs Tuesday. If that doesn't do it I will try the jumper. Fingers crossed. And THANKS!!!

I am replacing dist cap, plug and coil wires Tuesday, will check the innards of he dist at that time. I do have both type filters, recently replaced. OPSS. As in oil pressure safety sitch. As in I totally missed this the first and second time I read your post, as well as the posts of a couple of others. Could well be. If the new dist stuff does not work jumping the OPSS is the very next thing that I will try. Thanks so much!

The fuel pressure gauge will help confirm things too, including whether the OPSS is working correctly and bypassed correctly.

Make sure when you replace the distributor cap, you replace the rotor as well. They wear at the same time.

Ugh! Of course, and did not order one from Moyer. Got the other stuff today. Back to Moyer website, thanks for reminding me.