Mercruiser 3.0 not starting/ no spark

[Goldy1997]

I am pulling my hair out on this thing now. I have a 1991 Mercruiser 3.0 that had a complete fresh rebuild in 2011. It ran great last season. I had a reputable local marine shop winterize it. Now it wont start and I have no spark at all. I have replaced the plugs, coil, points, condenser. I have disconnected the tach, checked the shift interupter switch, and there is 12 volts at the coil. I have even disconnected the purple wire from the coil and fed 12 volts directly to check for spark and there is still nothing. I figured I would try this site before I call the marine shop and say a lot of four letter words on how my boat will not start now. Any suggestions? The cap & rotor were new in late 2011 also.

 

[alldodge]

Re: Mercruiser 3.0 not starting/ no spark

Do you have a kill switch and if so is it in the run position?

 

[Goldy1997]

Re: Mercruiser 3.0 not starting/ no spark

No kill switch, its an I/O in an open bow. Just has an ignition key switch which has been checked

 

[Don S]

Re: Mercruiser 3.0 not starting/ no spark

How are you checking for spark? If you pulled the coil wire out of the distributor cap held it about 1/2" from ground and had nothing, it could be the coil wire it's self or corrosion in the coil tower. Try one of the plug wires and see if it works.

 

[Goldy1997]

Re: Mercruiser 3.0 not starting/ no spark

i have tried cranking over the engine with a spark plug grounding to the block, no spark at all. I tried putting 12 volts from the battery directly to the coil, no spark. I've eliminated the tach, the neutral safety switch, the shift interrupter, the resistance wire, the coil, the points, the condenser, the black wire connecting the points to the coil on the distributor, the coil wire, the cap, the rotor, and the ignition switch. I did happen to be in the engine compartment while cranking the engine over with the ignition on via a remote starter switch and had a black ground wire that was connected to the ground side of the slave solenoid give off a small puff of smoke and get hot. Upon inspection of the wiring under the dash and checking continuity of the harness, I found nothing out of the ordinary but I am, however, in the process of rewiring the gauges to clean it up. I am beyond frustrated with this!!!

 

[alldodge]

Re: Mercruiser 3.0 not starting/ no spark

Don't know if you you have a thunderbolt 4 or 5 ignition so I'll give you both. Run through this and see where it takes you

 

[Howard Sterndrive]

Re: Mercruiser 3.0 not starting/ no spark

have you cranked it with the distributor cap off to verify the distributor is turning?

 

[Goldy1997]

Re: Mercruiser 3.0 not starting/ no spark

It doesn't have the Thunderbolt ignition. Yes I have tried bumping the engine over with the cap off to verify it rotates. I have determined that this site will not be of much help to me & have decided to just take it to a professional

 

[bonzoscott]

Re: Mercruiser 3.0 not starting/ no spark

have you cranked it with the distributor cap off to verify the distributor is turning?

That's a good one! Roll pin in shaft sheared cause busted up valve seal got in the oil pump! Been there....

 

[andyspoppa]

Re: Mercruiser 3.0 not starting/ no spark

I had the same issue...until I put a new distributor cap on it...changed the rotor, points, plus plugs...but the cap cured my issues! Just a thought...

 

[Bt Doctur]

Re: Mercruiser 3.0 not starting/ no spark

were the points installed and gapped correctly?

 

[Jonnybbad]

Re: Mercruiser 3.0 not starting/ no spark

I have determined that this site will not be of much help to me & have decided to just take it to a professional

Ouch, that was pretty harsh. I think I'm gonna cry. Somebody hold me.:drama: