OMC Cora 4.3 HO igniton

[pra100]

I have ask on this subject before with no one being able to help.So beings my splitfire ignition is failing,no spark intermeditaly,especial after engine warms up and and you try to start.I am looking for ideas on replacing it with a distributer.I know I would have to come up with some form of a shift interupt system.<br />Anyone with any ideas.<br />It is a 91 omc cobra 4.3 HO.I have replaced the coil pack,and the ignition sensor with no help.<br />Philip

 

[headstartnana@aol.com]

Re: OMC Cora 4.3 HO igniton

Don't think this is much help BUT if I was in your position, I'd drag it into the mechanic. One other thing might be the "gang" plug is corroded.

 

[pra100]

Re: OMC Cora 4.3 HO igniton

Problem with that is there is no one around my area that knows anything about omc cobras.So I try to do all my own wrenching.<br />I figured out how to master the cobra shift cable problem,which after 2 years still shifts perfectly.<br />I was thinking of putting a Hei dist.in it,or trying to find a older point type dist. and putting in it.

 

[Reel Poor]

Re: OMC Cora 4.3 HO igniton

Do you have a wiring diagram of the ignition stytem?

 

[pra100]

Re: OMC Cora 4.3 HO igniton

Here is the wiring diagram of my ignition system.<br />

[/IMG]

 

[KaGee]

Re: OMC Cora 4.3 HO igniton

Do you have an OMC shop manual? Do you own a reliable volt/ohm meter?<br /><br />That's where you need to start. There is bound to be a proper troubleshooting procedure in that book.<br /><br />Have you checked out the oil pressure switch? How about the water temperture switch? From the looks of the drawing, any false signal from either one may cause the module to shut down. <br /><br />Many intermittents are also caused by poor electrical connections. Have you traced down and inspected those connections, specifically common ground points? Have you tried cleaning the harness plug? <br /><br />Other than swapping parts, what have you done to try and figure this out?

 

[pra100]

Re: OMC Cora 4.3 HO igniton

So far what I have done is stated above,replace coil pack and ignition sensor,both of which were suggestide.I do own a omc shop manual.What I am finding is there is little info on this system beings it was only tried for 2 years by omc.<br />I do have several very reliable volt/ohm meters.<br />I thought about ground to the module,I checked the black wire to module for ground both when it does start and run and when it doesn't start,it shows to have ground.I checked the p/b wire to see that it had voltage when it will not start and it does.I did check to be sure that it was a no spark condition when it doesn't start and there is no fire at plugs.<br />The strange thing is when it is cold it will start but hot it has no spark.I can take the dog house off of engine and it will start and run.<br />Once it starts there is no indication of a problem,runs fine,up and down the rpm range,for as long as you keep engine running.Let it set over five to 10 minutes and it won't start,cranks and cranks.So it sounds to be heat related.<br />I bought a big bilge blower to just try and bring outside air into it and let it blow right on module,this had no effect.<br />I have thought of the oil pressure switch or water temp switch,but haven't figured how to test them.Are they normally supposed to be open or close?<br />I haven't taken the plug from module loose and cleaned it,but that isn't next on list.

 

[Reel Poor]

Re: OMC Cora 4.3 HO igniton

Where are the shift interupter and shift overstroke switches mounted?<br /><br />They look like they are mechanically operated micro switches.<br /><br />If you don't solve the problem it looks like you could install a point distributor. Using an internally resisted coil, attach the Pr/B wire to the positive side of the coil and the W wire (along with the wire lead to distributor) to the negative side of the coil and be done with it. Well in a sence, just be sure to carry an extra set of points, condensor, and a feeler guage/dwell meter.

 

[KaGee]

Re: OMC Cora 4.3 HO igniton

Have you actually pulled a plug and checked for spark when this condition arises?

 

[pra100]

Re: OMC Cora 4.3 HO igniton

Yes I have pulled a plug and checked.I did that after I used the spark tester,just incase it wasn't working right.I even tried it in the dark to make sure there wasn't a spark.

 

[muc]

Re: OMC Cora 4.3 HO igniton

The oil pressure and water temperature switches put the ignition in S.L.O.W. and limit the R.P.M. so I don’t think that they are the problem. Other than checking all wire connections the only thing left is the E.E.M. module.<br />You will need a manual to do any troubleshooting.<br />Trouble is most of the tests require an OTC electronic ignition tester P/N OMC D3200.<br />And the real beauty of this system is after doing all the tests and still having the problem it’s recommended to replace the E.E.M. module!<br />Might want to think about converting to a conventional system.<br />Good luck, muc

 

[KaGee]

Re: OMC Cora 4.3 HO igniton

Looks to me that in normal circumstances, points TB & GB should be infinite ohms to ground. Point B should read zero ohms to ground. Point PrB should be 12-13VDC referenced to ground. Those would need to be confimed while running and rechecked again during failure.<br /><br />I'm curious as to the actual mechanical placement of that 12 amp circuit breaker. Wondering if it is cutting out after warm?? If it is, it would be cutting off the 12 volt supply to your coil pak. Just some thoughts as I ready for bed.

 

[KaGee]

Re: OMC Cora 4.3 HO igniton

One last thought... If you decide to convert, I would find a compatible distributor and then install a Pertronix kit and 3ohm Flamethrower coil. That eliminates the need for resistor wire. Pertronix works on 12 volts. Nuff said for tonight!

 

[pra100]

Re: OMC Cora 4.3 HO igniton

Ok here is a couple of pictures of breaker,switches,module,and coil pack.<br /><br /><br />

<br /><br /><br />

 

[pra100]

Re: OMC Cora 4.3 HO igniton

Update to my problem.<br />I bought a points type omc dist.a excell coil with external resistor and new plug wires to go with it.<br />Beings I will be doing away with my computer control,I will be doing away with my esa which is intergrated in the module.Reading on other forums I have heard of people doing this like merc.does and and connecting esa switch to neg. side of coil to momentarilly kill engine.Any thoughts on this?<br />Also can someone tell me how to hook my tach back up,I was thinking just hook tach wire back up to neg side of coil?<br />Also I believe I understand that there are two differnet voltages supplied to coil,one when cranking and one when running,is this correct?<br />Thanks for any help.