1990 Mercruiser 3.0 (Prestolite not Delco) No Spark

[ClearlkWellcraft]

I have replaced Cap, Rotor, Coil, Plugs, and Wires and have not had any success in getting spark. I have traced power to the coil but seems low (using analog meter not digital) this is very frustrating. Not sure why the voltage so low at the coil or is it normal to measure less than 12v on the Positive?

 

[Bondo]

I have replaced Cap, Rotor, Coil, Plugs, and Wires and have not had any success in getting spark. I have traced power to the coil but seems low (using analog meter not digital) this is very frustrating. Not sure why the voltage so low at the coil or is it normal to measure less than 12v on the Positive?

Ayuh,.... Welcome Aboard,... What about the points,..??

 

[ClearlkWellcraft]

I should have said that. I did replace the condenser and breaker as well. I removed the new cap and it seems like there is not any power even being sent to the distributor from the coil. I did read in an old thread something about the Tach causing this issue but even with the sender wire for it removed there still is not spark.

 

[Scott Danforth]

I should have said that. I did replace the condenser and breaker as well. I removed the new cap and it seems like there is not any power even being sent to the distributor from the coil. I did read in an old thread something about the Tach causing this issue but even with the sender wire for it removed there still is not spark.

do you understand points ignition? there is no power. the points only open and close the ground path to the negative side of the coil. the ignition switch provides power to the positive side of the coil thru two paths, path 1 is direct from the starter I or R terminal to provide full battery voltage during cranking. path 2 is thru a resistor wire or ballast resistor to provide about 9 volts to the points when engine is running

how did you set dwell? if you didnt use a meter, go back to that.

 

[ClearlkWellcraft]

do you understand points ignition? there is no power. the points only open and close the ground path to the negative side of the coil. the ignition switch provides power to the positive side of the coil thru two paths, path 1 is direct from the starter I or R terminal to provide full battery voltage during cranking. path 2 is thru a resistor wire or ballast resistor to provide about 9 volts to the points when engine is running

how did you set dwell? if you didnt use a meter, go back to that.

Scott
Thanks for sending me in the right direction. We now have it started and seems to be idling ok. The problem now is when we put in gear it stalls. I am thinking that now we have a timing issue.

 

[Scott Danforth]

Scott
Thanks for sending me in the right direction. We now have it started and seems to be idling ok. The problem now is when we put in gear it stalls. I am thinking that now we have a timing issue.

If you properly serviced the point and set the timing, you would not have a timing issue

Stalling going into gear could be a few things.

Idle is supposed to be 650 in gear

Could also be bad lower shift cable