multiple coils going bad

[Silvertip]

Re: multiple coils going bad

Point gap and dwell have a direct relationship. Set the point gap to spec and dwell will also be in the proper range with one big exception. Make darned sure the upper bushing in the distributor is not worn. If it is it will drive you nuts trying to get the engine to run good as the shaft wobbles and causes dwell angle changes. It's obviously best to use a dwell meter but points were set for a gazillion years before dwell meters were available so its not necessary. Heck, a match book cover used to work well. A dwell meter is a valuable tool to detect a worn distributor as dwell will vary considerably when it should be stable regardless of RPM. If you are unsure of the integrity of the wiring, by all means add the ballast resistor and new wiring. There should be another wire coming from the "R" terminal on the starter solenoid. That wire bypasses the ballast resistor during start mode.

 

[bruceb58]

Re: multiple coils going bad

A gazillion years before matches, they used two sticks to start fires too. Any of the marine mechanics that work on boats for a living use dwell meters.

 

[Buttanic]

Re: multiple coils going bad

If someone has a good feel for setting points with a feeller gage 99% of the time the dwell will be in spec. range if there is not excessive wear in the distributor.

 

[Silvertip]

Re: multiple coils going bad

And I might add that it is not rocket science to set point gap with a feeler gauge. And while we are on the topic of "age" why do you think so many younger boat owners have trouble starting their engines when its cold? It's simply because they have never driven a carbureted car and they expect their carbureted boat to start with the twist of the key just like their fuel injected car. FI boats excluded of course. True -- times and tools change. That does not mean the end result of an adjustment process is different. If one has a dwell meter handy by all means use it. If not, a $1.99 set of feeler gauges will get the job done nicely.

 

[bruceb58]

Re: multiple coils going bad

Silvertip...So I take it that you don't use a dwell meter to set your dwell?

Here are similar threads

Dwell Post 1

Dwell Post 2




Here is a quote from Don S

I've worked at a lot of different marine repair facilities, and have never worked at on where a feeler gauge was used as the only method of setting points.

 

[Silvertip]

Re: multiple coils going bad

No -- I didn't say I don't use a dwell meter. I said if one has a dwell meter handy, use it. If not, a feeler gauge will do the job. Not every boater doing his/her own work has a dwell meter, knows how to use it, or what it measures. Most however can relate to a feeler gauge. Besides, the only use a recreational boater has for a dwell meter these days is a boat -- and an older one at that. Cars have not used points for decades and unless one is a collector, you'd spend more time looking for the meter than it would take to do the job with a feeler gauge. I would also suggest that its faster doing the job with a feeler gauge even if you check dwell with the distributor cap off and just spin the engine. Even with that method, you will adjust the points a minimum of two times to get it right. Recheck after the cap is on and the feeler gauge technique wins the race hands down. Feeler gauge does it once and you're done.

 

[bruceb58]

Re: multiple coils going bad

piasajake,

Well now you have some opinions. You can buy a dwell meter for between $6(ebay) and $30(amazon) and be positive of what the dwell is or go the feeler guage route and it will be however good it can be based on what "feel" you have.

And, as Sivertip said, the dwell meter also can help you see if there is wear in the distributor bearing by seeing the dwell vary over RPM,

 

[Dunaruna]

Re: multiple coils going bad

[colour=blue]A multi meter is a 'must have' for anyone who wants to do their own maintenance. Most good multi meters have the dwell function.

I agree that feeler gauges will do the job but if a more accurate way to set the points is available - why not use it.

 

[piasajake]

Re: multiple coils going bad

I shouldn't have to worry about wear in my distributor, it is brand new. I am also quite familiar with using a feeler guage for adjusting points. I had a '74 volkswagon super beetle and gave it several tune ups over the 17 years I had it. I will get a dwell meter and make sure it is correct along with the other replacement parts I plan on installing. Probably won't be able to see how the results of everything ends up until next season though. Seems like it takes a while for a new coil to go out, if it does. Not much boating weather left this season.

 

[Don S]

Re: multiple coils going bad

Here is a story you might find interesting. We sold a brand new Bayliner 24 Classic with a Mercruiser 5.7 carbed engine with Bravo II outdrive back in 98 or 99. From day one, he had problems with coils going bad every 9 hours. They would crack the tower and short out.
One would think that would be an easy problem to fix, but it wasn't.
We changed the complete engine wiring harness, distributor, ignition modules, alternators, starters, batteries, battery cables (Even went one size larger) all under warranty. Checked voltages so many places and times for Merc reps I can't imagine what they thought they were looking for. The Merc service reps also visited the boat on several occasions.
Would still kill off a coil in 9 hours.
After a couple of fixes at the end, we actually ran the boat for 12 hours with no problems. Gave it back to the customer, and he lost a coil in 9 WTF
Finally the lawyers came in for their turn. We were eventually instructed to install a NEW 5.7EFI engine and Bravo II Drive and transom shield at Mercruiser's expense, and Bayliner (Both Brunswick companies) provided brand new wiring harness, all new instrument panels, and a new circuit breaker panels for the boat.
No problems sense, and that was a few years ago.
The old engine was also re-sold. Went in another boat with a blown engine. The owner was told about the problem and if it continued to be a problem we would refund all his money. He has run it a lot, for a several years now, and never a lost a coil.
What caused the problem? Who knows. But it wasn't the engine or engine adjustments that caused it.

 

[piasajake]

Re: multiple coils going bad

One final question. I know the resistor wire and a ballast resistor do the same thing. Which one of the two would be more reliable and work better or last longer and would have less chance to fail?

 

[imported_rosco]

Re: multiple coils going bad

toss it and buy an electronic conversion kit. no more points, no more resistor wires, no more setting gaps, alot more dependability.

or, try an accell super coil. mabe a mallory. there kind of hard on points though.

ballast resistor works better than the wire, but on my 69 duel point distributor hotrod, i was going through them about 1 a year. was running a mallory coil at the time. best part about the ballast resistor, easy to replace. bad part is, when it goes, your engine dies immediatly. i started getting the dodge type with 2 sets of resistors in one body. when one went, just switch the wires to the second set.

 

[Mischief Managed]

Re: multiple coils going bad

Hey Don S, ever use a Fluke 87 or 88 (or something like that) DMM to monitor and record min-max voltage in sitautions like this where electronics inexplicably die over and over again?

 

[piasajake]

Re: multiple coils going bad

Well, I'm getting ready to get my boat ready for the new season. I have not done any work on it since my coil went bad on it last season. Here is what I am considering doing. To eliminate possible problems with parts of the electrical system that may or may not relate to the coils to keep failing, I am planning on replacing the following: plugs, plug wires, coil, alternator, and starter. I am also planning on replacing the resistor wire with a ballast resistor and regular wire. I replaced the distributor last season with a new one wich included new cap, rotor, points and condenser. Any other suggestions or ideas would be appreciated to help prevent the coil from failing.