OMC 4.3 V6 No Spark from coil.

[dslagle]

Hello I have a 1885 OMC 4.3 V6 in my 20’ SeaSwirl Cuddy Cabin. I'm not getting any spark from the Coil at all. I know a little bit about engines but by no means am I educated in this field. I disconnected the Coil Wire that connects to the distributor cap and held it up to some metal and did not see any spark. I should se spark correct? So I thought that it could be the Coil. I replaced the Coil and that was not it. The Engine is trying to turn over but no spark. It sounds like the Starter is working fine. Could this be the starter solenoid? I can see the starter and it has what it looks like a solenoid attached to it with the Red cable that attaches to the Positive end of the battery. Is this the starter solenoid? At the top of what I’m thinking is the Starter solenoid is some brown plastic that looks like it has a cracked hole in it. Is there anything else in between the Starter and the coil that could effecting my problem? If you understand what I'm talking about please any info would be great. Going to buy a Repair Manual tonight but any help would be great! . Thanks Danny

 

[andrewgroup]

Re: OMC 4.3 V6 No Spark from coil.

The basics of Internal Combustion Engine (ICE) are;<br />Fuel, Spark and Air.<br /><br />In order for the coil to produce a spark it must have a collasping electrical field, produced by either a set of points opening and closing on the primary field coils or a electronic box producing the switch.<br /><br />In either case, the points are opening and closing against a rotating distributor shaft or the electronic module is getting a pickup signal from a module against a rotating distributor shaft..<br /><br />If points are being used, (not likely) you can rig up a set of points using rubber coated screwdrivers and you can simulate points opening on the coil and should be able to produce spark at the plug...(up against the engine)<br /><br />I recommend using a new plug leaving all 6 in for fire protection...Also wetting the manifold down dilute any fuel that may be present...<br /><br />(Any good auto parts shop can test a coil)<br />some may be able to test spark module if electronic..<br /><br />IF you can turn off your fuel line, then removing all six plugs will allow easy cranking....<br /><br />A timing light on the plug wires is a better test to see if you have a spark...<br /><br />Just a bunch of random thoughts for encouragement..<br /><br />Good Luck...

 

[Lark40]

Re: OMC 4.3 V6 No Spark from coil.

If he has a pre-1990 OMC 4.3 engine, he has points.

 

[boat doc]

Re: OMC 4.3 V6 No Spark from coil.

you can check to see if you are getting a signal from your points or electronic ignition by using a test light. Hook the clip end of the light to the + side of the coil, and the probe side to the - side. Get someone to turn your engine over, if your light flashes you have signal. If you have signal, but no fire, it is your coil. Another thing to test is see if you have voltage to your coil (should really do this first) Also If you have points, try to use a low amp test light, points draw fewer amps than electronic ign, and a higer amp test light will not flash.

 

[metwrench]

Re: OMC 4.3 V6 No Spark from coil.

I agree with the 2 replies, however Boat doc has a great way with the test light EXCEPT before you will see a flashing Light you must Disconnect the NEG Wire at the coil.<br /><br />So, Clip end of the 12volt test light to the positive side, and disconnect the negative side of the coil wire. Now touch the test light to the negative side and have someone Crank the Engine...Light Flash ? You have a good Primary circuit, Replace the coil.<br /><br />Light dont flash ? You need to check for Bat Power and the positive side of the coil with key on. If you have power then go to the negative side of the coil ( wire goes to the points ) Check the points for grounding and Gap.<br /><br />John

 

[dslagle]

Re: OMC 4.3 V6 No Spark from coil.

If anybody remembers this Post I'm not getting anything to the Coil. I have confirmed this. What am I missing here? I've checked all the fuses. Found one of the 50amp fues was blown but I think that was controlling my Trim stuff. Do you think it could be just a lose wire somewhere. It fired up once Yesterday and then I could'nt get it to go again. The Battery is fullly charged and connections are good. Could it be my Igniton Switch. I mean it's turning things over. I bought the Shop Mannual but It does not go into detail for this kind of problem. What about the Safty Switch? Could this be it? Any help is greatly appreciated. Thanks, Dan

 

[Lark40]

Re: OMC 4.3 V6 No Spark from coil.

Power to the coil comes from two sources: the starter solenoid and the alternator.<br /><br />Check the wire from the coil + to the starter solenoid for continuity. Check the solenoid stud while cranking to see if if has power.<br /><br />The alternator-to-coil wire should be a resistor wire. Check it for continuity and power.<br /><br />You can run a jumper lead from the battery + to the coil + to try to start the engine. Don't leave it attached after starting.

 

[rattana]

Re: OMC 4.3 V6 No Spark from coil.

Dan, first thing you need is a 12 volt test light or a voltmeter. A cheap radioshack meter will do. Less then $20 bucks. If you have no voltage to the coil with the key in the run position, you will have to trace out the circuit with the meter. You can either start checking at the coil or the ignition switch. Sometimes it is ackward to get at the terminals and wires, but be patient. You have 12 volts on the start terminal of the key switch when trying to start. You should have +12 volts at the ignition or run terminal with the key on. This wire should go to your starter solenoid then your positive side of the coil. You will have reduced voltage (about 9 volts) at the coil to protect the coil. The voltage will be reduced by either a ballast resistor or a resistance wire near the coil. For the -12 volts or ground, this part of the circuit will include the shift interupter switch, the negative side of the coil. It also goes to the distributor points as well as for the signal to the tach. Check all the wiring to ensure proper connections. I think you should check out the shift interrupter switch maybe the fault is there. Also check that the points are opening and closing when the distributor turns.

 

[dslagle]

Re: OMC 4.3 V6 No Spark from coil.

Thank You Rattana. Do you know where I check for this Disconncect Switch? and also how will I know if the points, (when you say points you mean under the distributer cap), are turning. Man thanks so much everyone for your help I really appreciate it. I will check this stuff out this weekend and if I get the boat running i will all owe you some smoked Salmon! Give me you address I'll ship it to you. My E-Mail is dslagle@bnctransit.com

 

[andrewgroup]

Re: OMC 4.3 V6 No Spark from coil.

Can you remove the distributor Cap? It will reinstall in the exact same position because of milled detents in the casting of the distributor and the screw clamps that hold the cap in place.<br /><br />If you can remove the cap, have a friend engage the key and watch to see the distributor in action. The black plastic item on top is called the rotor. Note the long strip of metal that has in the very middle on top a worn spot. This center area come into contact with the carbon plunger located on the bottom inside of the distributor cap. The Coil fires a high voltage into the top center hole of the distributor cap and it then goes out and to the selected sparkplug as the rotor rotates in synch with the rest of the engine. This whole process is called timing.<br /><br />Below the Rotor on the shaft of the distributor is an area that has six flat faces and six high points. Mounted inside the base of the distributor are the points. This set of contacts opens and closes as a small cam follower pushes against these flat and high spots. When the follower is exactly on the high spot, the points will be opened to a predefined specification, say .019"...this is the points setting.<br /><br />One side of the contacts is connected to ground and the other side leaves the distributor and goes to the ignition coil.<br /><br />when the follower is on a flat spot, the coil is shorted to ground, thus drawing current since the other side of the coil should have 12 volts. This current is interupted when the points open. The coil itself is really transformer and collapsing field within the coil produces an response from teh coil and it generates a magnified voltage spike that leaves the coil via the center lead.<br /><br />Another item of interest is the condenser. It's really a capacitor designed to absorb the spark that would normally appear when the points pull apart from each other. If this was shorted it would make the points always appear closed and the coil would never get the collapsing field.<br /><br />As someone has stated before, the coil requires +12v or something near that on one side of the coil. Locate the condenser wire and the wire leaving the coil and note which side of the coil they attach to. The other side should have 12v when the ignition is on or in the start position. If not, several things could be interupting that 12v's. I personally would use a test wire directing from the 12 volt battery to the coil..Careful not to go to the wrong side, (Sparks and melt the wire)<br /><br />Then I would see if the coil emits a spark..<br /><br />Go for it.....

 

[dslagle]

Re: OMC 4.3 V6 No Spark from coil.

Thanks Andrew and thanks everyone. Well everyone has helped me so much with this problem. I have learned so much and now I know so much more about my electrical system. Come to find out I was getting 12 volts to the coil and the coil was sending current to the distributor. So I opened the wiggled a couple of wores and she fired right up. So glad it was something simple and now I can go out and catch some Salmon. Thanks everyone. Tight Lines!

 

[andrewgroup]

Re: OMC 4.3 V6 No Spark from coil.

"wiggled a couple of wores" What the heck is this....I'll recheck my manual and see if I have this on my boat.