timing question on 96 mercruiser 3.0LX

sltintexas

Petty Officer 2nd Class
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May 28, 2010
Messages
109
I have a question on timing a 96 mercruilser 3.0LX with EST ignition. I am a little stumped on the a few lines in the manual.

the following is from Service Manual #13 page 4b-25
3. Bypass the shift interrupt switch by disconnecting wires at shift interrupt switch. Temporarily join the engin hardness wires together.

If you look at the picture attached, Do I have the correct connections circled in red? Connect the purple wire to the wht/grn wire (female purple to male wht/grn).


I also know about the jumper wire needed at the distributer..that part I understand.
 

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fat fanny

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Re: timing question on 96 mercruiser 3.0LX

Yes joint them together thats why they are landed male female opposite of each other.
 

sltintexas

Petty Officer 2nd Class
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May 28, 2010
Messages
109
Re: timing question on 96 mercruiser 3.0LX

Everytime I disconnected the purple wire, engine would die. I tried with it off, and connected to green/white wire and engine wouldn't start.

Am I doing something wrong??
 
Joined
Mar 27, 2010
Messages
3,008
Re: timing question on 96 mercruiser 3.0LX

I have a question on timing a 96 mercruilser 3.0LX with EST ignition. I am a little stumped on the a few lines in the manual.

the following is from Service Manual #13 page 4b-25

If you look at the picture attached, Do I have the correct connections circled in red? Connect the purple wire to the wht/grn wire (female purple to male wht/grn).
QUOTE]

In that picture, the purple wire and wht/grn wire are basically the same wire, in a series to get to the distributor. The only thing that makes them different is the switch in between, which when activated connects the two together.
 

Rocky_Road

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Oct 8, 2008
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1,798
Re: timing question on 96 mercruiser 3.0LX

Everytime I disconnected the purple wire, engine would die. I tried with it off, and connected to green/white wire and engine wouldn't start.

Am I doing something wrong??

Try letting the engine reach running temperature before you jump the wires for base timing. When you put the wires together going to the shift interupt switch, you are taking away the timing advance...and that may cause a 'cold' engine to refuse to idle.

The other possibility is that someone has set your timing without following the proper procedure, and the timing is too far off to run with the shift switch wires connected. If that is the case it may be possible to jump the wires as instructed...have someone turn the engine over while you use your timing light...and see if you can get an idea of where you are at. You should be able to set the timing within the 'ballpark' while trying to start, and when the engine fires off do the fine tuning at the correct idle speed.

When everything goes as advertised, you will notice a hefty increase in rpm's when the shift switch wires are disconnected and returned to the switch. This tells you that you have gone back into the normal spark advanced mode.

Happy boating!
 
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