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mercruiser 1999 4.3 litre wont start

E

emptyhead123

New member
I have a 4.3 litre thunderbolt ignition mercruiser engine 1999 that isn't starting. the battery and starter is working fine. i have check the spark plugs and there is no power going to them.

does any one have ideas what the problem could be?
 
Re: mercruiser 4.3 litre wont start

yes in neutral kill switch ok. I'm not getting any spark at the plugs.I have tried a different coil but no joy.
 
Re: mercruiser 4.3 litre wont start

Try a jumper wire straight to the coil from the pos side of the battery.

Crank it and if starts then you will have to pull the wire off to shut it off.

we will go from there .
 
Re: mercruiser 4.3 litre wont start

Thanks i have ordered a new coil just to be on the safe side.
apart from the coil do you have any other suggestion on what the problem might be? weather in Ireland is very wintery wont get a chance to work on boat to the weather improves.
 
Re: mercruiser 4.3 litre wont start

before you order something you don't need why not just run a wire from the pos side of the battery to the pos side of the coil and start the boat ?
 
Re: mercruiser 4.3 litre wont start

"yes in neutral kill switch ok."

Empty, which kill switch are you refering to?

There may be two of em.

the obvious one up front at the controls, (red Toggle) theres another on the Shift Plate, on the starbord side Exhaust elbow. It kills the ignition momentarily during gear shifting. Depending on model, it either grounds neg of coil, or kills +ve power to coil, so for testing, you have to either unplug it, or jumper across it.
Sorry if im tellin you stuff you already know, but not clear which you were refering to. Mark.
 
Re: mercruiser 4.3 litre wont start

get a 12v test light

turn key on

put light on positive of coil, if it lights up you have power to coil

if not then the ESS is bad or wiring is bad
 
Re: mercruiser 4.3 litre wont start

I tired the wire from the positive side of the battery to the coil still not joy. Have ordered a new coil.

Found the kills switches and checked them all ok but still no spark at the spark plugs.
 
Re: mercruiser 4.3 litre wont start

hi there
just reading through what you've said, what make of boat is it, could be a simple 30 pence fuse under the dash have seen these on sea rays, if thats not the case then i would cancel the coil and order an ignition amplify unit that sits inside the distributor. have changed a lot of these, easy to change, sends a singal for the coil to see that the engine is turning over. let me know how you get on
 
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