Mercruiser 4.3l Alpha dies when ignition key is released

[mwesley]

Need help! 1999 Regal with Mercruiser 4.3l Alpha engine, starts but dies as soon as ignition key is released. Keeps running as long as you hold key in start position. I have changed the ignition switch, fuel filter, and oil pressure switch. Wired around kill switch and new oil pressure switch to test them but still dies. tested fuel pump, drained tank of old gas, refilled with new. Anyone have any other ideas?
Mike

 

[Bt Doctur]

Re: Mercruiser 4.3l Alpha dies when ignition key is released

have you checked the main harness plug at the engine. running with the key in start means your getting power from the solenoid, not running in "on" means no 12v to the coil.

 

[mwesley]

Re: Mercruiser 4.3l Alpha dies when ignition key is released

have you checked the main harness plug at the engine. running with the key in start means your getting power from the solenoid, not running in "on" means no 12v to the coil.

I have not, I am not with the boat right now but I will check that on Thursday. Thank you so much!!

 

[mwesley]

Re: Mercruiser 4.3l Alpha dies when ignition key is released

I have not, I am not with the boat right now but I will check that on Thursday. Thank you so much!!

I would also like to know how to test the coil to make sure it is good. You had said to check the main plug in the harness, to make sure it is good connection and clean? Thanks again!

 

[Don S]

Re: Mercruiser 4.3l Alpha dies when ignition key is released

It wouldn't start at all if the coil was bad.

Check for voltage on the purple wire on the ignitions switch, also check the voltage coming from the kill switch (don't just jump it, check for voltage) and check on the coil, the purple wire on the alternator, and the purple wire on the choke to see where the voltage is missing.

All tests with a meter are done with the black test lead to a good ground, and the ign. sw. in the run position.

also try disconnecting both wires going to the shift interrupt switch.

 

[mwesley]

Re: Mercruiser 4.3l Alpha dies when ignition key is released

It wouldn't start at all if the coil was bad.

Check for voltage on the purple wire on the ignitions switch, also check the voltage coming from the kill switch (don't just jump it, check for voltage) and check on the coil, the purple wire on the alternator, and the purple wire on the choke to see where the voltage is missing.

All tests with a meter are done with the black test lead to a good ground, and the ign. sw. in the run position.

also try disconnecting both wires going to the shift interrupt switch.

Thank you, Don, great information! Going out in the morning to do the tests, will get back with you if it does not work.
Thanks again! & Have a great evening!