1992 OMC Cobra with no spark

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Hmm. That's how it was when I got it but I will definitely try that.

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

You really need the actual wiring diagram from a real OMC manual.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Bruce,
I am ordering Friday along with new coil, cap and rotor if I need them or not.

Any suggestions for a source for the manual? Ebay?

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

I have a manual for a 1990 or so but it doesn't have the electronic distributor. Ebay would be best source.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Yes probably so.

Hoping someone could post the diagram so I don't have to wait.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

I'll have to take a photo and post but what I have is four wires to the coil. Two on each side. This is the way I got the boat.

A black ignition wire sending 12+ volts and a black wire from the ignition module in the distributor to the positive side.
A wire, that I assume is the ground and a purple wire from the ignition module connected to the negative post. The assumed ground wire is also black and goes into a wire harness with a bunch of wires.

Interpolating this info, and according to what Bondo said, I'd say the purple wire from the module should be on the Plus + terminal, along with the ign. wire.

Next the black wire from the module should be on the Neg - terminal, along with the other black wire that goes into the harness, this has to be the Tach pickup. There is no such thing as ground going to, or coming from the coil terminals, that might even burn it out!

So far, this is my theory,,, whatever damage was done, if any, to the coils, or ESA module due to your testing, must be determined, because even if you wire it the right way now, and it may not work? we won't know if any of these parts are preventing that?

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

You may be right.

I just might sit back and wait for the manual (wiring diagram) and the parts before I do anything else.

But I will post some pics asap so everyone can see what I am looking at.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

That black wire going back into the harness just might be your shift interrupt wire CSA, or the Tach wire either way there should be a Tach wire to go onto the Neg - coil terminal as well. I'm not familiar with electronic ignition, as my old boat a 22' Celebrity SS cuddy with twin 205hp 4.3 OMC Cobra drives was a 1986, pre electronic ignition, and I can't remember how wiring was on the shift interrupter. C.R.S. syndrome,,,lol

 

[MikDee]

Re: 1992 OMC Cobra with no spark

Okay Mohave, Go to this link, then the OMC manual, goto page #431 and you will find a wiring diagram, with the coil, & Distributor wiring.

Boatinfo - boat brochures and manuals for boats and marine engines!

There are 4 wiring diagrams on those 2 pages, but I think you have to interpolate between your diagram, & the Ford diagram on pg 430, the upper right, not all the wire colors are there, I think because apparently they didn't want to get redundant?

Between the 2 diagrams, you can see the wire colors are PURPLE from the Dist to the Pos + terminal, and PURPLE from the wiring harness to the Pos.+ terminal, that's it.

Next, on the Neg - terminal, put Black from the Dist. along with GREEN/BLACK from the ESA module, and that's it!

It doesn't show any other wires on the coil posts, but personally I thought there should be a Tach wire on the Neg - terminal? Maybe it's on another diagram

Let me know how you make out.

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

It doesn't show any other wires on the coil posts, but personally I thought there should be a Tach wire on the Neg - terminal? Maybe it's on another diagram

I think it get's it from the ESA module. My thinking is that the grey wire coming from the ESA plug may have the Tach signal on it.

The diagram on the bottom right is the diagram for the 92-93 4.3L. The only problem is that this is not a factory OMC manual. It's the Seloc so you have to take any info learned with a grain of salt.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

That is great guys.

The link took me to the home page so I will do some searching when I get a chance here at work but in the meantime here are some pics.

IT must be that the purple and black got mixed up before I got the boat. Maybe I burned out both coils in the testing also. Hopefully did not damage anything else.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark




Pic of the ignition switch shows a frayed wire. The solid yellow wire that goes to the hour meter.

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

That purple wire on the negative side of the coil looks like it has a new connector on the end. Who knows if that's the original wire or not at this point. You just need to follow it to see where it goes.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

That's the ignition module wire. See the module in the distributor with the purple coming out. That has to be the problem.

Will try that this weekend with the module connected correct. But may have to wait for new coil.

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

The ignition module should have a wire wired to 12V with key on and the other wire going to distributor negative post.

By looking at this picture:
View attachment 226105
Purple to +12V
Black to negative on Distributor.

Your coil is likely fine. They are pretty robust unless you run them with spark plugs with too big of a gap or bad spark plug wires.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

Well, that looks like a clean low hour engine! I just hope it's not been compromised by water, or weather.
Is that a 2bbl, or 4bbl carb on there? I'd hafta go with a 4bbl myself. So, tell us what size, & kind of boat that's wrapped around that engine.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

That is great guys.

The link took me to the home page so I will do some searching when I get a chance here at work

Did you get to page #431?

Okay, on the home OMC page, just scroll down the middle to the bottom, and erase the page it's on, then type in 431, and hit enter it will take you right there!

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

OK getting spark now but just wants to backfire
Plug wires are correct. I loosened the distributor and rotated it back and forth from position it came to me in but didn't seem to change much.
The negative battery cable is overheating and sparked a little but maybe that's just from cranking it so much?
I'll get in that manual and see how to set initial timing I guess to make sure the distributor isn't 180 degrees off.
Any other suggestions?

 

[Bondo]

Re: 1992 OMC Cobra with no spark

OK getting spark now but just wants to backfire
Plug wires are correct. I loosened the distributor and rotated it back and forth from position it came to me in but didn't seem to change much.
The negative battery cable is overheating and sparked a little but maybe that's just from cranking it so much?
I'll get in that manual and see how to set initial timing I guess to make sure the distributor isn't 180 degrees off.
Any other suggestions?

Ayuh,... Yer cable is burnin' up from Corrosion,.... Either the ends are Bad, or possibly the Whole cable is Bad,...
With electricity, Resistance = Heat,...

My guess is the distributor is 180? out,....

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

when you spin the distributor around your just want to spin the inside so the rotor is 180 from where it was not the whole distributor because that would put the hole where the wires come out to the other side away from the coil, right?

I'm still going the read that section but seems to make sense,