How to test a coil ?

[bigtoe]

I have a four winns 180 horizon with a 3.0L . recently fitted a new starter, did a test and she was starting on the first turn of the key, had a good couple of days, noticed the alternator belt getting loose and kept an eye on the volt readings, all seemed as though not was charging, no belt squealing.
Got her home to flush and the starter was just rapidly clicking , boat would turn over a few times. So i charged the battery. Now she will turn over but not fire.
Seems no spark at the plug. I have checked the purple wire on the coil and have 12V when the key is turned to the first position.
Do coil break down just like this , is there test I can do on the coil instead of just buying one and hoping?
Thanks in advance

 

[alldodge]

Coils hardly ever go bad. What is your motor serial number?

 

[bigtoe]

Hi all Dodge, serial number is 4011312544 engine model is 302C PBYC thanks

 

[alldodge]

Oh its an OMC

You have the EST ignition and is tested

 

[bigtoe]

Its strange it has a Volvo warranty card in the booklet but an OMC operational manual. Thanks for the PDF I will look at it in the morning, briefly tho it mentions the shift interrupt switch, is that something that stops the spark if the shift lever is in gear? if so where would i find that as I may of broken a joint in the wiring there whilst checking the starter motor.

Many thanks again

 

[alldodge]

briefly tho it mentions the shift interrupt switch, is that something that stops the spark if the shift lever is in gear?

The OMC uses a ESA module which interrupts the spark so it can be shifted out of gear. Here is the wiring for the OMC and while a V8 it works the same

 

[bigtoe]

thanks all Dodge, so if i have broken a wire joint for the interupter there would be no spark ? Any idea where i might find this interupter switch and what it may look like ?

 

[bigtoe]

Ok i have had a proper look at the diagram and the pdf now, Its a bit strange as I do not appear to have any cables coming out of the right hand side of the distributer. i.e b the white wires used for timing process and c wire from shift interrupt switch . I have never noticed any cables going to it. should there be any one the 3.0L do you think? thanks

 

[alldodge]

Instead of an interrupter switch, you have ESA module, so the wires on the right would not be used. It would only be needed to set timing

Hey GA_Boater can you move to OMC and Lou have some thoughts?

 

[KM7]

I do agree that frequently coils get replaced when there is really nothing wrong with then. A clicking starter almost always just indicates low voltage that is not enough to turn the starter. That is usually just a dead battery that is an east test.

There are tests of the coil, check your manual. Mine, a 5.8 L 91 Ford is Primary + to - 1.43 to 1.45 Ohms. This is very low and many meters can't read that low. The Secondary, from - to the center output is 7.5 -8.7 K Ohms.

Looking at the diagram you do have an interrupter switch and an over-stroke switch. The interrupter switch sends power to the ESA module AS you shift. It shuts of as soon as the shift is complete. This usually happens going both into and out, of gear, forward and reverse. It usually is very easy to go into gear and the ESA activates for just a split second. Coming out of gear can take a little bit longer and the ESA will be on a little bit longer. The Overstroke will kill the signal to the ESA if you are in fwd gear above idle. That is true no matter what the interrupter switch does.

While this will help you understand your system, it really does not affect starting as ESA should be off in neutral. The Overstroke switch arm should be on the center of the movable overstroke housing. That is the part that connects to the shift cable with the barrel nut. You can move it up and down by hand to hear and feel the ESA activating.

 

[bigtoe]

Hi all , thanks for the posts. I have gone through everything and I have to say I missed the sparks at the plugs. Having someone else to turn the boat over is so much easier gauge things. So i have tested coil, All OK, Plugs all get sparks. I Have checked battery, and the resistance from battery to starter, all good, no drops. I have fuel ( squirting into the carb), I have a sparks at the plugs, I have air. All ran perfect before bringing home to run up. I have removed all the plugs and turned over just to make sure no water is there, nothing turned over so quickly with out the plugs in. I cleaned all the plugs before putting them back, Plugs and oil, fuel filter have all only done three trips this year.
I am at a loss for what to try next. Its like something is turned off stopping it firing. Its not even trying to fire, just turns over as if there is no sparks or fuel.
Is there anything that could be stopping it fire up? anything else to try next.
I would rather not take it to shop as i prefer to know how to fix bits incase it happens out at sea!
Thanks in advance

 

[alldodge]

I have fuel ( squirting into the carb), I have a sparks at the plugs,

Motor turns over, you have fuel and spark and it won't hit. My next thought is you have water in your gas.

Take a spark and fuel something is goning to burn unless the carb is flooding the motor

 

[bigtoe]

Thanks All Dodge, I was thinking the same. Drained fuel from the carb bowl, re-filled with fresh fuel. Still the same. Pulled the fuel pipe into a tub and turned over, fuel pump works well. Drained the newly fitted water separator filter into a coffee jar, no water found. Put it all back together, checked the needle on the carb. Turned over and plenty of pressure at the carb, fuel squirting into it the carb when operating the lever but not flooding. Still not firing up, not even trying to start.
Took out the plugs again, checked for sparks at them all. All good. Plugs didn't seem over wet considering the amount of times I turned the boat over and squirted fuel int carb either from at the carb or whilst turning over.
Turned it over again without any plugs in , turns over real quick then, no water or anything else coming from the cylinders.
I think i am now stumped as to what to do next. Cheers

 

[Scott Danforth]

is your tach registering about 200-300 RPM when you crank it over?

what is the voltage being read by your gauges when you crank? does that voltage stay above 12? or dip below 9? if your voltage dips below 9 volts, you wont have any spark when cranking

if the motor isnt turning over at least 150 RPM while cranking, it will never fire even if everything else is perfect

rapid clicking is a really low battery (under 9 volts) or a really bad connection somewhere

so.....is the motor spinning over nice and fast when cranking, or just barely turning? my guess is that you have at least one bad connection between the battery and the starter or battery and the ground and your not spinning fast enough.

 

[alldodge]

Is the spark white or blue and not orange or red?

Happen to have a spark gap tester

There is no reason with gas and a spark there shouldn't be some kind of combustion

 

[Leekneelake88]

I’m having similar issues on a 4.3 just found the small fuel filter where the line hooks to the card was really cloged waiting on my shop to revive the filter and try again I’ll let you know.

 

[bigtoe]

Well we changed the plugs and got it started although rough as hell. I got a new distributer and rotor arm and after a few bad starts she now starts back up as before. How strange it went from starting easily to not starting at all after driving her home on the trailer.
Any how starting now so must of been the spark from Distributer cap/Rotor Arm. As the coil tested out as ok.
Thanks for all the help.
Now onto my next issue.

 

[alldodge]

Idling rough re-check firing order

 

[bigtoe]

It’s starting ok now all dodge , I am not a hundred percent sure it was the distributer cap that needed changing but it’s all good now.
apart from water getting to my cylinder number 4 . But that’s on another thread

 

[gm280]

Well glad you got something worked out. But water in any cylinder isn't good news. Hope it is just a head gasket and not a block issue. Either way, try to keep all your engine post in one thread so everyone knows what you are dealing with and the history of all issues. Ask the mods to merge all your threads into one for that reason.