advance timing goes to zero

doboy13golf

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Mar 17, 2009
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I have a 93 ski supreme with a mercruiser 350 mag. converted to electric timing (a delco hei from marine power) initial timing is dead on 8* but advance timing goes to 0* under throttle. put on water and power is way down and it will not get beyond 3000 rpms. I am at a lost? Help.

ps i can hear the advance shut off when i plug the advance cut off in to set initial timing.

Also I had to run another lead to coil from key switch to get a full 12v to the coil.
 

flargin

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Aug 13, 2008
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540
Re: advance timing goes to zero

Also I had to run another lead to coil from key switch to get a full 12v to the coil.

I would say if you find out why you are having problems with the 12v you will find the problem. I have a feeling you may be under-powering the HEI system and it is shutting down.
 

bruceb58

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Re: advance timing goes to zero

ps i can hear the advance shut off when i plug the advance cut off in to set initial timing.
What do you mean by this? Are you verifying this with a timing light?
 

doboy13golf

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Re: advance timing goes to zero

I would say if you find out why you are having problems with the 12v you will find the problem. I have a feeling you may be under-powering the HEI system and it is shutting down.

i am getting 12v to coil. ran new line cause the other ran thru a resistor that took it down to 8v for the old points system. the 8v line would not even get a spark on the coil

could it b my tach? works on the dash display. does it comunicate with the coil?
 

bruceb58

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Re: advance timing goes to zero

Definitely take your tach off for now. It hooks up to the negative side of the coil. You should see what the directions for the distributor says about tach hook ups to see if they have a seperate tach output.

You need to verify everything with a timing light. Don't do anything by "ear". Once you set base timing, run the engine and verify advance with the timing light at Idle ROM and up. You should be getting at least 25 degrees total advance from idle setting.
 

doboy13golf

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Re: advance timing goes to zero

Definitely take your tach off for now. It hooks up to the negative side of the coil. You should see what the directions for the distributor says about tach hook ups to see if they have a seperate tach output.

You need to verify everything with a timing light. Don't do anything by "ear". Once you set base timing, run the engine and verify advance with the timing light at Idle ROM and up. You should be getting at least 25 degrees total advance from idle setting.

yes all is verified by timing light. advance is going back towards 0* during acceleration. Im lost
disconnected tach no change
 

bruceb58

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Re: advance timing goes to zero

OK..next question...is this a standard rotation engine? What is the model number of the distributor?
 

bruceb58

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Re: advance timing goes to zero

you have a left hand or right hand rotation engine and what distributor dod you buy for? I can't find that model number by googling it.
 

doboy13golf

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Mar 17, 2009
Messages
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Re: advance timing goes to zero

you have a left hand or right hand rotation engine and what distributor dod you buy for? I can't find that model number by googling it.

481084 delco HEI kit on mercruiser 5.7 (OD624566) it had points
 

JustJason

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Aug 27, 2007
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5,321
Re: advance timing goes to zero

i looked it up and found that it was an est system.

start the engine, let it warm up.
join the 2 white wires on the ignition module together.
disconnect the shift interupt switch and temporarily join the engine harness wires together.
Point, shoot and twist the distro housing until you set your base timing. After you got it shut off the engine. Torque down the distro housing bolt, disconnect the white module wires, hook up your shift interupt switch again.
Should work now, if it doesn't then you probably have a bad ignition module.
 

bruceb58

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Re: advance timing goes to zero

Next question. Which way does you engine rotate? I know you have an inboard and it may have a non standard rotation.
 

JustJason

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Re: advance timing goes to zero

Perform the procedure I described then report back. Bet it works :)
 
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