No spark on OMC Cobra 5.8L 8-cylinder inboard motor

[cuttlefish310]

It's a 1994 model, low hours and recently completely stopped producing a spark.

OK, did all the amateurish things, no luck so started down the well known "remove and replace" procedure that invariably proves nothing other than reduce your bank roll.

This included:

1. New spark plugs (gaps fine)
2. New plug leads (not fibre optics)
3. New expensive coil
4. Two new marine batteries
5. Checked and replaced numerous wires with broken insulation and one rotted out battery cable
6. New ignition module - the epoxy sealed type with all the gizmos in the module
7. New distributor cap - in case of cracked cap on old one
8. 12v wire connected from battery to positive on coil, coil negative earthed - nothing

Employed two independant marine Sparkies who, after six hours troubleshooting and $500 later, found nothing!

Checks performed showed:

1. 10v ex coil when cranking the engine
2. By passed ignition switch - nothing
3. By passed coil wiring - nothing
4. By passed everything else - so they said - nothing
5. Not a sign of a spark ever, anywhere. This is third coil so unlikely it is the problem
6. Confirmed rotor in Dizzy is spinning during cranking
7. Every single system shows a good, healthy 12.5V but ain't no sign of a spark anywhere

One item that is always there is a really hot coil. Even with the motor shut down, the coil can hardly be touched when the engine is static - wonder why this is?

Got us all beat!

Any advice appreciated.

 

[Silvertip]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

There is no such thing as a fiber optic spark plug wire. You are also in the "General Electrical" section and should have posted this in the OMC I/O section. That's where the knowledge is on an OMC I/O.

 

[1979caravelle]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

There is no such thing as a fiber optic spark plug wire. You are also in the "General Electrical" section and should have posted this in the OMC I/O section. That's where the knowledge is on an OMC I/O.

i had hot feeling coil with no spark or start...found out it was the shift interrupt switch was grounded out...fixed switch...fired right off....this is on a merc 165 inline 6...i'm not sure of your setup...

 

[Don S]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

Disregard, I looked at the wrong year, you don't have points ignition.

 

[Don S]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

This information came from a Volvo manual, but it's the same exact setup you have. Volvo and OMC were in a joint venture in at that time.
It will give you troubleshooting instructions for the Prestolite BID ignition system you have.

https://www.dropbox.com/s/nt9hs1um9yq1vxz/Prestolite Ign.pdf

 

[HT32BSX115]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

One item that is always there is a really hot coil. Even with the motor shut down, the coil can hardly be touched when the engine is static - wonder why this is?

Howdy,


That would be a result of current flowing through the coil at all times...........indicating either a wiring error/short or a possible component failure.

Neither of the above should be happening.

This is where a model number would really help. ALL the 1994 models have electronic ignition. and a few have electronic spark control. You can identify them by going to [click the following:] BRP -- Parts Catalogs to view the parts breakout.

Model numbers are as follows.



[clicking below will give you an error]
1994

5.80

584ACPMDA 1994
584AGPMDA 1994
58FACPMDA 1994
58FACPMDM 1994
58FAGPMDA 1994
58FAGPMDM 1994
58FBDPMDA 1994

If you have points, you either don't have a 1994 model or someone in the last 17 odd years has changed out the distributor for a points type.

Also, the boat being a 1994 model year doesn't make the engine/drive a 1994 model. Many boat manufacturers frequently use "last years" model until they run out. So you could have a 1993 model (earlier [or even later] if someone else swapped it)


Regards,



Rick

 

[cuttlefish310]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

Thanks for that info Don and you are spot on, the diagrams etc. are a mirror image of my system.

I'm still tearing my hair out over this problem as I have just had two independant marine electrictians spend some seven hours troubleshooting the electrics, bypassing the ignition switch, bypassing the ignition module, relays and "other things" - all to no avail, not even the dribble of a spark!

No they are suggesting I fork out another five or six hundred bucks and invest in a self contained Dizzy with the coil. module and everything else all-in-one.

Got me absolutely beaten .................

Thanks again!

 

[cuttlefish310]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

Thanks Rick, mine is the 584ACPMDA model without the standard points etc. e.g all epoxy enclosed!

No idea where I got the fibre optic plug lead garbage from ................. think my brain is overcooking trying to resolve the issue.

I'll head on over the the right OMC forum and try again there...

Thanks also to the other guys for replying, much appreciated from Down Under!

 

[Don S]

Re: No spark on OMC Cobra 5.8L 8-cylinder inboard motor

Thanks Rick, mine is the 584ACPMDA model without the standard points etc.
I'll head on over the the right OMC forum and try again there...

You are in the right forum, the links Rick posted are to a parts lookup program, not a forum.

I have just had two independant marine electrictians spend some seven hours troubleshooting the electrics, bypassing the ignition switch, bypassing the ignition module, relays and "other things" - all to no avail, not even the dribble of a spark!

If you remove (bypass) the module, you aren't going to get spark. You now have the manual, get your meter and do some actual troubleshooting instead of parts swapping like the shops were obviously doing.

The problem with the BID ignition is the module is NLA (no longer available) and when you do find them, they are very expensive.

So do all the tests shown in the manual, then let us know what you find.