Ignition problem 1999 Mercruiser 3.0 litre
 

Hey Everyone,

I've got a 3 litre Mercruiser built in 1999 with only about 30
hrs.(salt and freshwater) on the engine. Motor starts and idles fine
in low and high rpm. Under a load at high rpm's the engine will cut
out (similar to a kill switch). The fuse to the ignition (15 amp)
usually blows and the engine won't restart until a cooling off period
of about 2 hours. If anyone has ever experienced anything like this
or has heard of this happening I'd like some ideas as to why. Thanks
in advance, Sean

Ignition module or coil I'd guess.
"Sean" wrote in message
om...
Hey Everyone,

I've got a 3 litre Mercruiser built in 1999 with only about 30
hrs.(salt and freshwater) on the engine. Motor starts and idles fine
in low and high rpm. Under a load at high rpm's the engine will cut
out (similar to a kill switch). The fuse to the ignition (15 amp)
usually blows and the engine won't restart until a cooling off period
of about 2 hours. If anyone has ever experienced anything like this
or has heard of this happening I'd like some ideas as to why. Thanks
in advance, Sean

Thanks for the insight. I did replace the ignition module last week
and the wiring harness that runs to it as well. Starts and idles
fine; haven't had the opportunity to get it out and run it yet.
Thanks again, Sean

I'm still having the same problem. I've swapped out the coil, the
module and the ignition switch and still the same result. Very
frustrating. Any other suggestions would be appreciated. Thanks,
Sean

Check for voltage with a meter when you have whatever problem you have.
Make sure there is 9.6-12V at the (+) side of the coil of the power to the
ignition module.
Bill

"BenC" wrote in message
om...
(Sean) wrote in message
. com...
I'm still having the same problem. I've swapped out the coil, the
module and the ignition switch and still the same result. Very
frustrating. Any other suggestions would be appreciated. Thanks,
Sean


15amp ignition fuse seems a little lite. check that the main harness
plug at the engine is plugged in correctly, remove it and add
dielectric as well.
if that doesnt work do some basic tests, compression, spark, fuel
pressure etc.
do these while the fault is present.

Thanks everyone for your insight and suggestions. I finally tracked
the problem to a group of wires running along the top of my engine
block that was chaffing towards the rear of the engine and shorting
out the ignition. The wires had been wrapped in electrical tape and
the group of wires were zip-tied to a coolant hose running fore and
aft. When the throttle was moved full forward, linkage to the
carberator would press down on the hose and therefore press the wires
into the block and short out. I find it hard to believe someone from
the factory would attach these wires to a coolant hose...but there
they were. Thanks again for your help, Sean