HEI module
#1
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From: Chicago
Is there a way to test these to see if it`s good or bad ?
https://www.westmarine.com/sierra-18...yABEgJDrPD_BwE
https://www.westmarine.com/sierra-18...yABEgJDrPD_BwE
#2
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Joined: Aug 2010
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From: Cape Coral FL
Most auto parts stores have a tester. I don't know how accurate they are, but I have had a few tested over the years and none of them ever failed the test. It always led to more troubleshooting and in every case I found the problem elsewhere.
#5
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From: Chicago
The engines are doing weird stuff.
We can`t figure it out .
Everything works fine till it doesnt .
One day out of nowhere neither engine would start .. no tach signal.
drive it home , starts back up.
Same tune in both engines , one will be fine the other will drop duty cycle like a clock and only in gear .
Eddie Young says get rid of the daytona boxes they are not needed and cause RF interference.. maybe thats it.
Unfortunately I don`t know Mefi and how to rewire it so .. good times
We can`t figure it out .
Everything works fine till it doesnt .
One day out of nowhere neither engine would start .. no tach signal.
drive it home , starts back up.
Same tune in both engines , one will be fine the other will drop duty cycle like a clock and only in gear .
Eddie Young says get rid of the daytona boxes they are not needed and cause RF interference.. maybe thats it.
Unfortunately I don`t know Mefi and how to rewire it so .. good times
#6
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Joined: Sep 2014
Posts: 864
Likes: 250
From: Portland, OR
Most likely not your issue but mine had this mess that a big time shop missed while diagnosing why it would not run... and "foul plugs" total garbage but that's a long story.
The tiny little relay on the right and the dist. block runs 2 of my 4 fuel pumps, looks pretty trustworthy eh?. All been replaced/ cleaned now.
Since you have nothing else better to do
it may be worth checking out if nothing else but to clean. I had to dig under some covers to find these.


The tiny little relay on the right and the dist. block runs 2 of my 4 fuel pumps, looks pretty trustworthy eh?. All been replaced/ cleaned now.
Since you have nothing else better to do
it may be worth checking out if nothing else but to clean. I had to dig under some covers to find these. 

#8
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Joined: Jan 2006
Posts: 3,598
Likes: 1,167
From: taxachusetts
Most likely not your issue but mine had this mess that a big time shop missed while diagnosing why it would not run... and "foul plugs" total garbage but that's a long story.
The tiny little relay on the right and the dist. block runs 2 of my 4 fuel pumps, looks pretty trustworthy eh?. All been replaced/ cleaned now.
Since you have nothing else better to do
it may be worth checking out if nothing else but to clean. I had to dig under some covers to find these.

The tiny little relay on the right and the dist. block runs 2 of my 4 fuel pumps, looks pretty trustworthy eh?. All been replaced/ cleaned now.
Since you have nothing else better to do
it may be worth checking out if nothing else but to clean. I had to dig under some covers to find these.
#9
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Joined: Jan 2006
Posts: 3,598
Likes: 1,167
From: taxachusetts
Is there a way to test these to see if it`s good or bad ?
https://www.westmarine.com/sierra-18...yABEgJDrPD_BwE
https://www.westmarine.com/sierra-18...yABEgJDrPD_BwE
short story,I got a tune for a starting point on mefi4b,,little did I know,the tuner had jacked up the dwell 2-3 x more than a stock merc.I'd be going along and the engine would just die.finally stumbled upon that one,,never blew another module.did get good at replacing them while boat was under way.
#10
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Joined: Nov 2004
Posts: 14,068
Likes: 3,668
From: On A Dirt Floor
you run holley efi,right.is there a place for inputting dwell?
short story,I got a tune for a starting point on mefi4b,,little did I know,the tuner had jacked up the dwell 2-3 x more than a stock merc.I'd be going along and the engine would just die.finally stumbled upon that one,,never blew another module.did get good at replacing them while boat was under way.
short story,I got a tune for a starting point on mefi4b,,little did I know,the tuner had jacked up the dwell 2-3 x more than a stock merc.I'd be going along and the engine would just die.finally stumbled upon that one,,never blew another module.did get good at replacing them while boat was under way.
Many car tuners have run into the ignition dwell issue too. Maybe because many didn’t understand it.
Fun fact - Carb’d motors I used to literally bypass the module when using the crane box with the gm est dist , i just used the dist as a magnetic pick up distributor.




