Started out as a good day on the water. 4.3 mercruiser

[Newbie@boats]

4.3 mercruiser, was going along just fine and all of a sudden it started spitting and sputtering brought it back to an idle and it died. Got towed back to the launch got the boat home was able to get it running again gave it a rev not being in gear and it sputtered and I shut it off. Haven’t been able to get it started since.

What I did was remove a spark plug and hook it up to the wire and I’m not getting any spark.

Pull the main wire off the top of the distributor from the coil and stuck a spark plug in it and grounded it, I got 1 spark and that was it. I had it cranking over for 20 seconds. I’m not sure if a coil fails like that?

Cap, rotor, plugs, and wires all new end of last season.
The serial # on the tag is showing k010819

Any help would be great.

 

[flashback]

water in the fuel?

 

[alldodge]

I got 1 spark and that was it.

Need a scanner, and do to no spark Start with distributor car and rotor (I know just replaced last year). Make sure 12V stays on the coil full time when ON and when cranking.

Next it gets into things like crank position sensor

 

[Newbie@boats]

I’m not sure I can hook up a scanner to this engine. It’s carbureted if that makes a difference.

I changed the fuel filter yesterday before going out.

After poking around some and having someone to help me crank it over and check for spark I rechecked the spark at the spark plug wire and I will get one spark from the plug at the first initial crank and it’s gone.

From there I just happened to see out of the corner of my eye the coil arching out. It was coming from the postive wire to the center of the coil. I removed the coil and for whatever reason I had it upside down and there was liquid leaking from the center of it.

Do I just replace the coil and see what happens? Or did something further down the line fail and cause the coil to fail?

 

[Newbie@boats]

This is where the coil was arching out

 

[Bondo]

From there I just happened to see out of the corner of my eye the coil arching out. It was coming from the postive wire to the center of the coil. I removed the coil and for whatever reason I had it upside down and there was liquid leaking from the center of it.

Do I just replace the coil and see what happens?

Ayuh,...... That's where I'd start,.....

 

[Newbie@boats]

Thanks that’s what I’ll do.

I did smell fuel while trying to crank it on the lake, like it was flooding out, which is a possibility due to lack of spark.

Since I’m an over thinker and really want to limit any issues on the water, besides no spark/start could this cause other symptoms such as rough acceleration like popping/farting and hard starting? After it died I was able to get it started briefly again but it was a bear to get going, but once it did I tried to hammer down back to the launch but had a terrible acceleration and was spitting and sputtering-this whole event was probably 20 seconds or shorter.

 

[Scott Danforth]

Thunderbolt distributor or EST?

If thunderbolt, does the ignition trigger have 2 wires or 3?

 

[Newbie@boats]

I’m 99% sure thunderbolt
I’m 100% sure ignition trigger is 2 wire

 

[DeepCMark58A]

That will do it.

 

[Scott Danforth]

Get the updated 3-wire trigger

 

[Newbie@boats]

Get the updated 3-wire trigger

That’s all I seem to be finding. Red/white green/white and an additional ground wire?

 

[dubs283]

That’s all I seem to be finding. Red/white green/white and an additional ground wire?

There's a fairly simple test to determine if the ignition sensor in the distributor is faulty. Surprised no one has posted the manual page

Once you've concluded the sensor is at fault, a new coil along with an OEM sensor is your best bet

 

[Newbie@boats]

There's a fairly simple test to determine if the ignition sensor in the distributor is faulty. Surprised no one has posted the manual page

Once you've concluded the sensor is at fault, a new coil along with an OEM sensor is your best bet

I’m almost thinking of just upgrading it if there’s a better option just to have a piece of mind on the water.

 

[dubs283]

If you want to upgrade the option from merc is the hei delco ignition and it works fine.

Takes some savvy and a dedication to install with an understanding of electronic ignition systems

You could always revert to some kind of weird aftermarket system but they don't work as well ime, if your t bolt module is newer/not square big box style the OEM ignition sensor will alleviate your no spark/timing issues

 

[Newbie@boats]

Installed the new coil tonight and the boat fired up instantly. Didn’t have to pump the throttle or anything. With the boat in neutral I gave it a couple revs and there was no hesitation or anything. Revved smoothly.

Now my mind is wondering do I leave well enough alone? Or do I replace/upgrade the ignition system while I’m in there already

 

[Scott06]

Installed the new coil tonight and the boat fired up instantly. Didn’t have to pump the throttle or anything. With the boat in neutral I gave it a couple revs and there was no hesitation or anything. Revved smoothly.

Now my mind is wondering do I leave well enough alone? Or do I replace/upgrade the ignition system while I’m in there already

Why would you replace the ignition system if it’s working? The atB is a great system until the ignition module needs to be replaced $$$. Then typical replacement is a delco est. this isn’t any better except module rEllacement cost. Both are OEM quality systems.

 

[Lou C]

I would leave what you have as long as it's working right. I looked into the Delco EST to replace my points distributor but what I found is that it isn't genuine Delco but Sierra aftermarket. Don't know of all of the ones sold are like that but in my searching it seemed that way. Decided to stay with points for now. "Delco" EST is over $600 for a 4.3!

4.3L Delco Voyager EST Marine Electronic Distributor Kit

Michigan Motorz: your one-stop online shop for new & remanufactured marine engines, parts & accessories. Fast shipping, expert support worldwide.

michiganmotorz.com

I found this out by emailing Michigan Motorz and that's what they told me!

was thinking of changing over to a Delco EST system from points....

And I saw Michigan Motorz selling the complete kit described as https://michiganmotorz.com/4-3l-delco-voyager-est-marine-electronic-distributor-kit/ I asked them is this genuine GM or aftermarket, they did respond quickly and said it is Sierra aftermarket....so....seeing as how some aftermarket...

forums.iboats.com

 

[Fun Times]

Now my mind is wondering do I leave well enough alone? Or do I replace/upgrade the ignition system while I’m in there already

Sort of better to have an extra one on-board with the tools to change the sensor out should the need come to it out on the water.... Have a new rotor handy to as the rotor could get damaged during the R&R. https://www.mercruiserparts.com/bam/subassemblydetail/42256393/28171834

Genuine Mercury Marine parts, large inventory, fast shipping

Genuine Mercury Marine, Mercruiser and Mercury Racing engines, parts, propellers. Authorized dealer with large inventory, great prices, fast shipping!

www.mercruiserparts.com

 

[Newbie@boats]

Thanks everyone, I will keep everything intact as of right now. I will still order the 3 wire trigger, cap, rotor to keep on the boat as they are easy enough to change on the water if needed. I was hoping to go out again this weekend but the weather is not looking to great.