1992 OMC Cobra with no spark

[MohaveChuck]

I just got this boat and previous owner said was running last year. But he did think it needed a drive coupler so I got the boat cheap.

1992 4.3l OMC cobra.

Well I can't get a spark.

I took out all of the upholstery to get it replaced first so I thought it might be something to do with the neutral safety switch in the throttle control but it turns over just fine. I would think the neutral safety switch just controls the power to the starter.

Anyways.

I should have suspected something was up when I got it home and all the spark plug wires were removed and laying on top of the engine. Everything else seems to be in place and fine except for the plug and coil wires not connected. Also while turning it over a little fuel leak where the steel line goes into the carb.

After connecting the wires I pulled a plug wire off of #1 and also #3 and #4 and no spark. Checked the coil and I am getting 12 volts to the positive side of the coil and a high voltage jump out of the coil wire measured by a cheap multimeter. Just doesn't seem to come out of the distributor when connected back up.

I think I have the plug wires connected properly from a diagram I found here I think. But shouldn't I still get a spark even if the wires are not in the right firing order? I did the visual check for a spark with a plug in and the wire grounding to the block and also checked with the multimeter while cranking and not even a blip.

Could it be the ignition module? And what does that do? I know it takes the place of points and condenser but anything else? I can't find anything online on how to test it. Is there a cheap auto version I can buy just to rule it out?

Also tried it with the shift interrupt switch open and closed.
Could the shift module cause the problem?

I'm hoping it's something simple since the hour meter only says 254 and the engine is pretty clean. But who knows since I don't know the history of the boat.

Thanks in advance.

Chuck

 

[Bondo]

Re: 1992 OMC Cobra with no spark

I just got this boat and previous owner said was running last year. But he did think it needed a drive coupler so I got the boat cheap.

1992 4.3l OMC cobra.

Well I can't get a spark.

I took out all of the upholstery to get it replaced first so I thought it might be something to do with the neutral safety switch in the throttle control but it turns over just fine. I would think the neutral safety switch just controls the power to the starter.

Anyways.

I should have suspected something was up when I got it home and all the spark plug wires were removed and laying on top of the engine. Everything else seems to be in place and fine except for the plug and coil wires not connected. Also while turning it over a little fuel leak where the steel line goes into the carb.

After connecting the wires I pulled a plug wire off of #1 and also #3 and #4 and no spark. Checked the coil and I am getting 12 volts to the positive side of the coil and a high voltage jump out of the coil wire measured by a cheap multimeter. Just doesn't seem to come out of the distributor when connected back up.

I think I have the plug wires connected properly from a diagram I found here I think. But shouldn't I still get a spark even if the wires are not in the right firing order? I did the visual check for a spark with a plug in and the wire grounding to the block and also checked with the multimeter while cranking and not even a blip.

Could it be the ignition module? And what does that do? I know it takes the place of points and condenser but anything else? I can't find anything online on how to test it. Is there a cheap auto version I can buy just to rule it out?

Also tried it with the shift interrupt switch open and closed.
Could the shift module cause the problem?

I'm hoping it's something simple since the hour meter only says 254 and the engine is pretty clean. But who knows since I don't know the history of the boat.

Thanks in advance.

Chuck

Ayuh,... Welcome Aboard,... If yer gettin' a Spark outa the top of the coil, downstream is the cap, rotor, wires spark plugs then ground,....

Hold the coil wire near a ground,... If it'll Spark, the problem is Downstream, not up-stream,...

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Thanks Bondo,

Yes getting a spark, not sure if its a good spark but it will spark. Even tried a new standard GM coil that looked identical but not sure of the application and it did same exact thing.

Wires checked out on the ohm meter and cap and rotor looked good, did clean them also. Don't know what else I could do about those except order new ones.

What about the ground should I check? The ground to the coil?
We used different plugs when checking for spark and a screw driver and the multi meter and nothing.

I was thinking the ignition module. Not sure if it will have something to do with the problem.

Thanks in advance,

Chuck

 

[jbetzelb]

Re: 1992 OMC Cobra with no spark

If your getting spark through the coil wire the cap and rotor are next. Both are cheap and it would not hurt to have new there even if they arent the final problem. Is the 92 points or is it electronic ignition?

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

OK I'll order the cap and rotor, won't hurt to have spares if not the problem.

It is electronic ignition.

 

[Bondo]

Re: 1992 OMC Cobra with no spark

Thanks Bondo,

Yes getting a spark, not sure if its a good spark but it will spark. Even tried a new standard GM coil that looked identical but not sure of the application and it did same exact thing.

Wires checked out on the ohm meter and cap and rotor looked good, did clean them also. Don't know what else I could do about those except order new ones.

What about the ground should I check? The ground to the coil?
We used different plugs when checking for spark and a screw driver and the multi meter and nothing.

I was thinking the ignition module. Not sure if it will have something to do with the problem.

Thanks in advance,

Chuck

Ayuh,... The (-) ground post on the coil is how the primary circuit of the ignition, Tells the coil to Fire,...

If it's firin' outa the coil tower, the primary ignition is workin',...
Downstream from the coil, is the 2ndary circuit, which is as I said above,...

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

OK thanks again Bondo,

I will be checking those this weekend and probably just order new cap rotor and wires.

Any Automotive cap and rotor available at the auto parts stores that will work so I don't have to wait?

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

BTW Iboats.com doesn't list my cap and rotor for a 1992 4.3L OMC.

I think pre 1991 was points and condenser unless that does not make a difference.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

A simple question, If you have spark coming out of the coil, is there a rotor under the distributor cap?

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Yes rotor is there and everything seems to be clean and spins with cap off and motor turning over.

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

Unplug your ESA just in case it is affecting you.

 

[MikDee]

Re: 1992 OMC Cobra with no spark

Do you know if the Distributor was taken out of the engine at anytime?

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

I do not know if the distributor was taken out.

I'll unplug the ESA next time I try it and report back.

Thanks

 

[john cole]

Re: 1992 OMC Cobra with no spark

could very easily be the cap, the center electrode might be worn down enough to where is is not touching the rotor.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Still waiting on the cap.

Found the ignition module replacement online. It's a Pertronix 1589 that was cross reference by a couple of parts suppliers from the OMC 3854077 part number. Looks different.

I'm guessing if it's bad then the spark will not go through it?

Its about $100 so would like to try this last.

Anyone know if this is the replacement and if it is compatible with the shift assist module?
Or does the shift assist module work with any ignition?

Thanks

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

Its not the same module. ESA will work with it with some mods. A new CDI ESA will work with it with no mods.

Another option is replacing distributor with a Delco EST Voyager and a CDI ESA that is compatible with that distributor but that will be more money.

http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-121.html
Just keep in mind you are getting new cap and complete wire set here.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Thanks Bruce that may be the way to go.

Anyway to test the stock Ignition Module I have now to see if it is the problem?

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

Thanks Bruce that may be the way to go.

Anyway to test the stock Ignition Module I have now to see if it is the problem?

I don't have the OMC manual for your year. The correct one may tell you.

I just purchased a Delco Voyager for my 7.4l engine in my signature. The distributor I currently have works fine but it's one of those ones that was used in only one or 2 years and I want to be proactive and not get stuck if it fails.

 

[MohaveChuck]

Re: 1992 OMC Cobra with no spark

Question: I have the coil that came with the boat and I purchased a new GM coil that looks similar but not the correct one. I just wanted to rule out the coil that day. No change at all both coils act exactly the same. Once in a while I see a spark from the coil wire to ground but not everytime.
When bench testing a coil with just a battery shouldn't I get high voltage out. It seems to be reading the same voltage as going in. Unless I need a really good multimeter. I am just using a cheapy.

Thanks

 

[bruceb58]

Re: 1992 OMC Cobra with no spark

When bench testing a coil with just a battery shouldn't I get high voltage out. It seems to be reading the same voltage as going in. Unless I need a really good multimeter. I am just using a cheapy.

Thanks

I would love to see how you are trying to measure that! The high voltage spark only happens for milliseconds when the points open so unless you have an o-scope, you aren't going to be able to measure it.

You have a very good chance of blowing out your meter trying to measure something like that too. Meters don't like measuring thousands of volts.