Mercury 90hp CDI Coil issue

[mav6759]

OK, I have a 2001 Mercury 90hp....and I need help with the CDI coils...there is something I'm not understanding..Right now the motor is running off one cylinder, However, each coil is firing and have fuel...The compression is good....Now, this is a 3 cylinder and the motor is running off the 3rd cylinder...Here what I don't understand, if each cylinder has fuel and spark, why won't the cylinder fire....Now When I move the coil from the 3rd position to the 2nd position then that cylinder fires, samething when I move the coil to the 1st position...I was also told, a coil is a coil its going to fire or not...So I connected my spark plug tester and it shows fire to every coil...Am I missing sonething...

 

[wn6ngp]

I had a similar experience with my 90hp. It seemed like it was getting adequate fuel but not quite. I had rebuilt the fuel pump and got some gaskets out of order in the fuel pump. It pumped enough to get one cylinder running but not the others. there is something odd going on because as you say it doesn't add up.

 

[bstig60]

If you have adequate fuel in the tank, try pumping the bulb while the engine is running and see if the other cylinders pick up. If so, you may have a fuel pump problem, if not, there may be a blockage in the fuel line.

 

[racerone]

But the spark has to get there at the right time.----That is determined by the trigger unit and the wee wires going to the coils.