ignition troubleshooting ??? help please
 

I need help with no a no fire at the coil issue. When I turn the switch on the fuel pump comes on , the starter engages. I have swapped coils with the port but no difference. The red wire at the coil has power .

Please be more specific about what you are working on and what is going on.

Sorry! 1999 mercruiser 502 mag mpi

Probably a bad pick up module in the distributor.

+1

+2 or a ground issue

How do you check the pickup coil. I know what it is and where it's at. What is its signal? Ground? Positive? Should I use a test light or a meter. I have spoken with 5 different mechanics and all of them have been on the way for 2 weeks.

So I'm capable of testing anything, I'm just no what I'm looking for.

you can measure with an ohm meter. i believe you will have to take the distributor out. and spin the shaft. or put a starter button on the starter and crank the engine over while measuring reasistance. well i guess it would depended upon what kind of distributor you have. there is a sprocket that goes past a magnet as it is turning. if it is not picking up the teeth as they go by it will not start. or a twin engine boat swap the distributor's

He could probably swap the pickup coils and modules more easily than pulling distributors. If he does that he has to worry about getting the timing set again. The pickup coil is inside the distributor under the rotor. you have to remove the rotor, then you will see the pickup under it, mounted to the distributor body with two screws. Later model ones have three wires molded into it - a white with green stripe, white with red stripe, and a black one. You should be able to wiggle the pickup out past the distributor shaft without too much trouble.

Coil looks like this:

http://www.wolfiesenterprises.com/images/pulley18.jpg

I would swap ignition modules first just for grins. These rarely go bad, but they are easy to swap.

I'm assuming nothing has been disturbed wiring-wise that would result in a ground or other wire not being reconnected properly.

+3 They go bad with age and heat. Replaced several in my own boats over the years.