Need HEI Conversion Wiring Help - JeepForum.com
 
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post #1 of 10 Old 11-13-2009, 05:15 PM Thread Starter
guysnydr
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1983 CJ7 
 
Join Date: Aug 2007
Location: Pennsylvania
Posts: 203
Need HEI Conversion Wiring Help

Hi all, I am strongly considering an HEI swap on my 79 CJ7 258 6. Couple of questions. Do I still need the icm box that's on the DS inner fender or can I get rid of that with the swap? Also, what existing wires will go where on the HEI? I have a stock distributor now with some wires coming out of it and also of course the + and - leads on the coil. If someone could let me know I would sure appreciate it. Thanks in advance! - Guy Snyder Trout Run, PA

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post #2 of 10 Old 11-13-2009, 08:00 PM
Tager705
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1983 CJ7 
 
Join Date: Jan 2009
Location: Lincoln, NE
Posts: 61
All you need is a good +12 volt lead, I used the wire off my old coil, and a plug salvaged from a old GM pick up in the junk yard. You will need to move your dipstick a little and remove the old coil, and to adjust stuff if you still have stock air filter assembly it will need to be taken off while you adjust stuff. Also I found the distributor fits better with the vacuum advance parallel and closest to the fire wall. which requires the wires be about 180 degrees from their position on the AMC distributor. I will try to post a photo of mine in the morning.

83 CJ7 258 AMC TF999 Dana300
It Idles now :D
http://www.jeepforum.com/gallery/data/4/PIC-0294.JPG
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post #3 of 10 Old 11-14-2009, 06:12 AM
JeepHammer
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1973 CJ5 
 
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Location: South West Indiana
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The factory feed wire to the ignition coil has a resistor in line.
This will limit the effectiveness of the HEI ignition.
The factory wiring is undersized for the HEI ignition also.

The 'Easy' way to feed the HEI is with a Power Relay.
With a Power Relay, you will be able to feed the HEI with a CLEAN power source,
And you will be able to supply it with proper gauge wire so it works at well as any HEI can.

All new car ignitions use power relays to the ignition because of these facts.

If you need diagrams for this conversion, let me know and I can provide them.
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post #4 of 10 Old 11-14-2009, 11:20 AM
Tager705
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1983 CJ7 
 
Join Date: Jan 2009
Location: Lincoln, NE
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Here Are the photo's of how mine is oriented, I heard that the original coil wire has a Resistor in it but as near I can tell , mine runs great off the stock coil wire. There was a resistor on the old plug off the GMC pickup going from one pole to the other I cut it out and it works fine.


I just zip tied the old distributor wires to the fire wall.

Allot of people upgrade the feed with 10 gauge wire.

Mine runs fine on the stock wire I was out playing in a mud pit with it and it never missed a beat.

83 CJ7 258 AMC TF999 Dana300
It Idles now :D
http://www.jeepforum.com/gallery/data/4/PIC-0294.JPG
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post #5 of 10 Old 11-14-2009, 11:56 AM
Mike Romain
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1986 CJ7 
 
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Location: Off the Grid in Chester Grant
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I would use the stock coil power wire to turn on a relay to give full power to the HEI. Stock the coil only gets 9 or 10 volts when the engine is running. I think the hotter spark boosts gas mileage. I have a hot coil and get 21 mpg highway.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
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post #6 of 10 Old 11-14-2009, 06:33 PM Thread Starter
guysnydr
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Join Date: Aug 2007
Location: Pennsylvania
Posts: 203
Thanks a million for all this good info. Also, can I just unhook and get rid of the original icm box then?
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post #7 of 10 Old 10-06-2012, 10:14 AM
Schzap
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1984 CJ7 
 
Join Date: Sep 2012
Location: Blue Springs
Posts: 28
Ugh I feel so behind the curve here..im still working on getting my amc360 into my 84 cj7...i see many prefer the hei and it seemed cheaper than relpacing all the other "who knows if its good" parts, im aware ill need to change the gear..check...now about these wires... the hei has two..rocket science now..one is ground since i dont think any wiring on this is "switched ground" now the other i assume is 12 volts (ok so 11-13.8 depending on altenator) now...if you were me... which wire would you grab to hook it into this? i see no plugs that will slip into the plug hole on the hei..i assume i will need to use a couple of spade connectors and use some wires from the previous system.
oh heck..this may get me bumped but while here...which wires should i grab to run back for a fuel pump? my 360 has the mechanical pump plated off and i dont care to open that can o worms... i assume a swithced 12v, and just ground really close to the pump (say the holes i have to drill to mount the bugger?)
im not an idiot, but treat me like one please? more info is way better than missing some key component. like..."oh use a clutch alignment tool to get things straight before attempting to put the engine in...THAT would have saved me 3 days and about a quart of useful red blood cells....

or if by chance anyone is within driving distance of my home town...i will provide booze for help/advice. (this always works in the movies)
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post #8 of 10 Old 10-06-2012, 12:13 PM
Dngrs1
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Join Date: May 2009
Location: Mohave Valley,AZ
Posts: 866
Quote:
Originally Posted by Schzap View Post
im not an idiot, but treat me like one please?
Reviving a 3 year old thread when all the info you want is in the sticky's?
The HEI has an internal ground; the second wire is for a tach.

I would rather have a tool I don't need, than need a tool I don't have.
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post #9 of 10 Old 02-19-2013, 07:29 AM
Schzap
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1984 CJ7 
 
Join Date: Sep 2012
Location: Blue Springs
Posts: 28
I'm an electronics tech...with little background in vehicle maintenance so the magical secret grounds on my CJ were a mystery. Now that everything not a wire is now ground things became much more clear...like gauges with only one wire...thank you to all here who put up with noobs lost in a sea of information. John Strenk had the gauge info. That's a cool dude.
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post #10 of 10 Old 02-19-2013, 07:45 AM
brownbagg
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Join Date: Feb 2010
Location: pearl
Posts: 2,470
pertronix makes an electronic pickup that replaces the points in an old distrubor, I myself have the gm hei but the pertronix would have no wiring modification or looking for a junkyard distrubor
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