New Ignition Coil did not solve problem with abrupt engine shutdown

[bda953]

I have never had a problem starting the engine in the 5 years that I have owned this Bristol 27. But, I have had a problem over the last two years of engine abruptly shutting down after running for about 45 minutes. I finally decided to replace the coil to see if this would solve the problem. In my focus to change to coil, I forgot to open the fuel valve. After installation, the engine ran for about 10 minutes before it stopped due to lack of fuel. After realizing my error with the fuel valve and then opening it, I have not been able to start it since. My question is if emptying the carburator bowl completely would have an effect on starting the engine?

[Dave Neptune]

Priming

bda953, first welconme to the forum.
Yes it would not start with no fuel. If you have the mechanical pump all you need do is work the bail with the gas valve open and you should be able to "prime" the carb. May take a minute or two of working the bail. If you have an electric pump there could be a few ways to prime. But if wired properly the pump should pump while starting (cranking with the key on) and prime the system.
If you left the ignition on after running out of fuel you could easily burn up a new coil.

If there are more questions raidsed here just ask.

Dave Neptune

[ndutton]

I have a few questions:

1. Manual or electric fuel pump?
2a. Points or electronic ignition?
2b. What internal resistance is the new coil?

[sastanley]

bda, welcome.

I did exactly as you did a couple of years ago. (forgot to open the fuel line and it ran happily for about 10 minutes.)

I have a mechanical fuel pump w/ a Racor in front of it and a small MMI polishing filter just after it. About 30-45 seconds cranking on the starter and it re-primed, or Dave Neptune's suggestion for manual priming on the bale should work just as well. A word of caution (apologies if you already know this, however, it never hurts to plaster it all over the forum)....during any extended cranking periods (i.e., I consider extended cranking anything longer than 10 seconds) close the raw-water thru hull, so you don't back water up into the cylinders via the exhaust injection point. The engine must be running to expel the water out of the waterlift muffler, however, the water pump continues to dump water into the exhaust line/muffler during cranking.

Neil's questions address the other problem, which is the 45 minute shutdowns, which we'll work on next.

[Cellnav]

Coil

I have an electric fuel pump and before starting cold I turn the ignition switch on for a minute or two to let the fuel pump run before cranking to prime the carb. This tends to help starting when the boat has sat for a few weeks and the bowl is dry. Will this harm the coil? With points, I thought it would just charge the coil until the points opened when cranking.

[roadnsky]

Will this harm the coil?

Cellnav-
No harm if you're only running the ignition for a few moments.
What about wiring in a switch (off the battery) to do this so you don't have to turn on the ignition until starting? Just a thought...

[dvd]

I have a mechanical fuel pump and its seems to catch right up with this sort of thing. I replaced my entire fuel system last summer and after it was done the engine fired right up.

dvd

[ndutton]

I have an electric fuel pump and before starting cold I turn the ignition switch on for a minute or two to let the fuel pump run before cranking to prime the carb. . . . . Will this harm the coil?

Problem 1
Oversimplified, according to the coasties the electric fuel pump is not allowed to operate unless the engine is running for safety reasons. This is accomplished by wiring the fuel pump power through an oil pressure safety switch. The engine starts on residual fuel in the carburetor bowl (some installations help this along with a start bypass terminal but I've found this arrangement unnecessary), the oil pressure comes up, the switch closes and the pump pumps. Your description has the pump operating with ignition power only, specifically prohibited by the regulation.
Disclaimer - there are provisions for fuel transfer via an electric pump but the requirement here is engine operation must be disabled during transfer.

Possible problem 2
Somewhere I heard 30 seconds was the maximum allowable coil-on engine-off time without risking damage. One to two minutes seems like a lot.

[bda953]

It is a manual fuel pump. Will the diaphragm be damaged if no fuel is running thru it since I had fuel valve closed by mistake while trying to start it.

It has distributor with points

I purchased the new coil from Moyer Marine, it was part No. IGEM_05_31 Coil (with internal resistance). I'm not sure if the old coil had internal resistance. Would this make any difference?

What does "work the bail" mean?

[ndutton]

The 45 minute failure is the right timing for a coil problem but such is exceedingly rare for a points ignition. The new coil does no harm. I'd suggest replacing the condenser too just on principle. It's cheap.

As for fuel, we need to know if the pump is delivering fuel to the carburetor. You might want to check the oil level. If it's higher than usual and smells of gasoline that's a classic indicator of a failed pump diaphragm. For safety reasons the USCG requires the design of mechanical fuel pumps for gasoline to not spill gas into the bilge when the diaphragm fails. Instead, it's dumped into the crankcase.

You may well have damaged the pump. With the valve closed it was sucking until it was blue in the face, may have ruptured an already old diaphragm. We don't know for sure yet. Are you familiar with the main passage plug on the bottom of the carburetor bowl? Removing it will determine if there's fuel in the carb (have a catchment under the carb when you do it).

What does "work the bail" mean?

There's a lever (bail) to manually operate the pump. You can use it to prime a dry system or perform pump diagnostics.

Please don't try to start again until we learn more. A crankcase full of gasoline and fumes can be dangerous.

[sastanley]

bda, Neil's suggestions and comments are right on. A little more history from my perspective was that I had a rebuilt fuel pump with only hours of operation on it when I ran mine dry, so I cannot comment intelligently on what running an old diaphragm pump dry may do...mine re-primed without issue, but the internals were brand new.

Top expound on Neil's suggestions:
- The next step is to check oil level for the reasons Neil indicated above. If the oil level is normal and does not smell like gasoline....
- Step 2 is to use his picture to find the bail and see if you can manually prime. It will seem to move aimlessly, but you'll feel a little resistance when fuel moves into the pump body...this may take 5 stroke or 50..have a cool beverage of choice nearby...
- Step 3 is to then remove the drain plug in the carb and see if you can pump fuel out of the carb with the pump bail into a drain can. At that point, we'll know if your fuel system is re-primed. Replace the drain plug (sometimes there are two!!, one is a tapered thread, and the other (the main jet plug) has a washer..be careful with the washer!) and just a few pumps should fill the carb up again. You've now been fully qualified in re-priming your fuel system, but in the future you can usually skip step 3.

If you have questions about the carb stuff in step 3, ask..it is easier to get educated now, than tear up that little fiber washer!

If you come across problems with any of these steps report back. It may seem a bit tedious, but we have to isolate the individual systems and tackle them one at a time. Getting a coil was a good idea, but we'll move to the ignition system next..I'd also replace the condenser..that silly $5 part can mess with your head when troubleshooting ignitions. You can get one from Moyer (and I always like to patronize them when I can, so I tend to build my engine parts list and hit them up with a large order so I am not getting burned with $10 shipping charges for a $5 part), but you should also be able to find one locally once you know what you part you need. There are cross references available from places like cncphotoalbum.com..the late model A4 has a Delco distributor. I've had good luck finding ignition parts at my local NAPA, but walk in there with a part number, since most of them probably don't know about Atomic 4's.

It does matter if there is internal resistance in the coil..right now, that is a little beyond the scope of this exercise, and I've probably already spewed more info than necessary. They usually tell you on the coil label if you can still read it. For the purposes of troubleshooting, having a coil supplied by Moyer is the best scenario. For future reference, as noted above in other posts, do not leave the key in the "ON" position unless you are running the engine. Depending on the position of the points, it can burn up your fancy new coil.

edit - John Cookson over in another thread, pointed to this FAQ...good read. http://www.moyermarine.com/faq/4.2.html