76 CJ7 Ignition Control Module - JeepForum.com
  • 1 Post By CSP
LinkBack Thread Tools
post #1 of 8 Old 04-05-2020, 05:27 PM Thread Starter
Registered User
Join Date: Apr 2020
Posts: 3
76 CJ7 Ignition Control Module

After reading through many other threads I’m still stumped on an issue. Decided to replace my ignition control module after noticing it was leaking white stuff out of it and having some performance issues. Jeep will run and idles fine on it but sporadically going down the road it will lose all power and I would have to “crank” it again.

So I tried a couple of Crown units and when I would go to crank it I couldn’t get it to fire. Saw they didn’t have great reviews so I got a BWD instead and same issue. I’ve relocated the ground but am still having the same woes. Weirdest thing is that I can still use the old module to crank it up and it idles fine. Anyone have any insight on this?

I’m open to an ignition upgrade but couldn’t find a good video for it either. The write ups I’ve seen are good but I’d trust myself more to see it done.

Godawgs4498 is offline  
Sponsored Links
post #2 of 8 Old 04-05-2020, 06:44 PM
Registered User
1978 CJ5 
Join Date: Jun 2005
Location: Albany~town, Oregon
Posts: 2,482
I haven't had this issue but it sure sounds like something is cooking. I've subscribed to the ignition upgrades using MSD products, although I've yet to replace the ignition box with that MSD 6A. Kinda short on pocket of late.

The parts shop that stocks part for Skylab II will not have parts for our year/model of Jeep
We cannot accurately judge the trajectory of a speeding critter (cat, dog, sasquatch)
Record heat waves and floods only occur when we visit that area
turbogus is offline  
post #3 of 8 Old 04-05-2020, 11:22 PM
Registered User
Join Date: Aug 2002
Location: Colorado
Posts: 17,142
Swapping in a different ignition altogether is what I'd suggest. The Prestocrap ignition was bad with OEM modules and no surprise that Crown doesn't work at all.

I chose a factory GM HEI for mine. Worked well stand alone and ever better when it was incorporate into the fuel injection system to let it control spark timing.
uptillnow likes this.
CSP is offline  
post #4 of 8 Old 04-06-2020, 01:38 PM
Registered User
LJameson's Avatar
1990 YJ Wrangler 
Join Date: Jun 2008
Location: Trapped in the cesspool known as LA county
Posts: 3,960
Here you found the problem with the aftermarket replacement Prestolite ignition modules, they're all Chinese junk. I had the same problem with my 76, it would die driving and the replacement modules just would not work at all.

What I ended up doing was converting my ignition system to the Duraspark system used in (I think) 78 and newer CJs. Since it is a Motorcraft ignition system, I was able to find a module from an old Ford Econoline at the junkyard, and all the connectors to make the harness were available through Summit racing. Ever since I did the swap (about 15 years ago), I haven't had a single ignition issue.

1976 CJ7 Restoration:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
LJameson is offline  
post #5 of 8 Old 04-08-2020, 05:30 PM Thread Starter
Registered User
Join Date: Apr 2020
Posts: 3
Thanks all, I’ll take a look at some of the conversion write ups and scour YouTube to see if there’s one I think that can dumb it down enough for me haha.
Godawgs4498 is offline  
post #6 of 8 Old 04-12-2020, 10:22 PM
Registered User
1979 CJ7 
Join Date: Oct 2016
Posts: 104
So the best...in my opinion is an MSD 6 or similar CDI box. You can get them used for around 100 dollars, you cant fill these things so dont be scared. Then get rid of the oem ignition coil and get a Ford style e core ignition module. Lots of companies make them I have an older Mallory one that is nice. If you have the motor motorcraft dizzy keep it because it's fantastic. But go get a Ford adapt a cap and a large ford style distributor cap. They have the male terminals so you will need new wires but you want at least 8mm wires for this anyway. You will be highly impressed with reliability and throttle response. So if you shop around you will be put about 200 bucks maybe 250.
SC401 is offline  
post #7 of 8 Old 04-13-2020, 04:46 AM
Web Wheeler
BagusJeep's Avatar
1981 CJ7 
Join Date: Jul 2009
Location: Bali
Posts: 7,369
The Duraspark has a better rep than Prestolite ad was installed in millions of vehicles, its Achilles heel is that it draws amps when the engine is not turning but the ignition is on. That heat leads to damage.

The modules need to ground the primary windings in the coil to collapse the field and generate the spark, so all modules will get hot but the Duraspark is poor for this.

A better and cheap module is the GM HEI type. This has been used in millions of vehicles and is reliable but again needs a good heat sink. Jaguar called it an "ignition amplifier" and put it inside a very nice aluminium box and charge $150 for a new one, but it is just a $25 module in a nice box. The reason I mention it is that there is a Stealth HEI method, just hollow an old module box and wire and fasten an HEI module in, it will live quite happily in there.

The Prestolite distributor also has a habit of cracking its vacuum module. I suggest you discard and go for the Motorcraft style used 1979-1986. Get a 1979 to 1981 version, the advance head will allow more mechanical advance, otherwise you got to take it apart and flip the head over.

Almost limitless options for ignition from very simple and cheap eBay HEI clone distributors (not recommended) upwards.

BagusJeep lives in Bali.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1951 Willys CJ3A/MB/M38 - Little Willy
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline  
post #8 of 8 Old 04-14-2020, 10:36 AM
Registered User
1979 CJ7 
Join Date: Oct 2016
Posts: 104
Turbogus.. a less expensive option to the msd but still very good would the Echlin TP 44 by napa. It is a a very solid ignition module
SC401 is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.

Email Address:


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome