4.3 MerCrusier that won’t start and run

[FreeDally]

I have a 1999 MerCruiser 4.3 GM style, with a 2 Barrel Carburetor, that has had the cap and rotor, plugs and wires, and ignition coil all replaced. I’ve also changed the oil, oil filter, fuel water separator filter, and I believe that’s it. Because the bilge pump still worked, or else I was going to change that too. But after I changed all of that, I cannot seem to get the boat to start. I have tried to take the distributor out, and I haven’t had any luck, except I was lucky enough that it backfired once. I’ve been scratching my head for the past week, and I fear I’m going to go bald, or should I just bring it in and have the professional have their way with me? Please advise

 

[Scott Danforth]

welcome aboard

first, were the parts bad, or did you just like to throw money at your boat? What diagnostics did you do?

second, its never ever ever the coil. actually, its three out of a million changed coils that is actually bad so that was a complete waste of money

third, why would you try to take the distributor out?

now, take it to a professional, or stop, calm down and perform the proper diagnosis as to what is wrong.

someone will need to properly install the dizzy (at TDC of cylinder #1)
set the base timing
and then find what part that was changed incorrectly that lead to the non-start.

starting with the wiring to the coil and working thru the ignition system. you should have the TBV ignition. there is troubleshooting diagnostic trees in the stickies.
then moving on to the fuel system and working thru that.

 

[Rick Stephens]

Needs 2 things, spark and fuel. Yeah, spark has to come at the right time and fuel has to have the right air mixture. All sorts of niggly bits can prevent starting - old fuel being one of the most usual. Also a crudded up carburetor, distributor set so timing is far off, electric fuel pump not running. You mention the fuel water separator, there is also a filter on the inlet side of the carb, what does it look like? And when you pulled the separator, did you dump into a clear jar and see what kind of crap might have indicated a fuel problem?

There's no magic to fixing starting issues. Begin at the most likely and look closely.