2000 5.7 carb, no spark

[spydermann22]

i have a 2000 23SC with a carb. 5.7 Alpha One. No Spark
I have been doing a little reading trying to find the issue, so I will note a few observations that may help a knowledgable mechanic.
The Tack started acting strange a while back, it would be ok, then the needle would bounce all over. No affect on how the engine ran.
Recently the engine would have a slight sputter when throttling up to get on plane.
Last time out, it started right up and idled ok but the sputter was all of the time except idle.
I had never replaced the spin on fuel filter so I did this, as well as replaced the Distributer Cap, Rotor and plugs. Now no spark. I havent tested with a voltmeter yet....

[mmwjr]

How have you verified there is no spark? Could you have installed the wires in the wrong order? Did you verify the kill switch is in the run position?

[spydermann22]

Originally Posted by mmwjr

How have you verified there is no spark? Could you have installed the wires in the wrong order? Did you verify the kill switch is in the run position?

I verified that the wires to the cap are correct. I unplugged the throttle linkage microswitch and plugged the leads together (I didn't try with them not connected). Kill Switch is in run position. no spark from coil, old or new, tested cranking with a bolt leading from the wire to close to exhaust bolt. both coil leads have 12.5v to ground when the key is on. the coil has 14.5 ohlm resistance from the leads to the middle. This is 16.2 to the leads to the coil wire (2 more ohlms than without the wire. The Tach connection looked ok.

[spydermann22]

I did come across a ground wire that is not connected but I can't remember removing it, hopefullythe pic uploads.

[mmwjr]

Use he troubleshooting guide in Mercruiser manual #24 under Documents.

[spydermann22]

Originally Posted by mmwjr

Use he troubleshooting guide in Mercruiser manual #24 under Documents.

So reading that the Distributor Sensor should have 1000 ohlms minimum, Lead to Lead. This one has 8.7
It looks much different than anything on line.
Any idea what the P/N is? Possibly Quicksilver 87-892150Q02...?
its a carburated model with the round base.

[mmwjr]

I believe the two wire sensor has been replaced by a three wire one. Contact these folks for help.

https://www.mercruiserparts.com/merc...ookup-drawings

[spydermann22]

Thanks for your help Mike!

[spydermann22]

That solved it, the ol' 5.7 purrs once again!
i took the ground wire and found a home for it on the intake.
Thanks for the help!

[mmwjr]

Originally Posted by spydermann22

That solved it, the ol' 5.7 purrs once again!
i took the ground wire and found a home for it on the intake.
Thanks for the help!

So new ignition sensor; correct?

[spydermann22]

Yep, I think it was original so it made it 22 years.
Next project is the fuel Guage! I will start testing tomorrow

[mmwjr]

Originally Posted by spydermann22

Yep, I think it was original so it made it 22 years.
Next project is the fuel Guage! I will start testing tomorrow

There’s always a project.