1984 CJ7 ignition wiring help no spark from coil - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep CJ Forum > 1984 CJ7 ignition wiring help no spark from coil

FS: 2007-2013 Jeep Wrangler "HALO" Angel Eye KitThe Original 3/8" Ruffstuff Diff Cover!Building a Bumper?

Reply
Unread 05-23-2014, 03:24 PM   #1
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
1984 CJ7 ignition wiring help no spark from coil

I have a 1984 Jeep CJ7 with the 6 cyl 258. Although I use this forum frequently, this is my first post. So please bear with me.

Last weekend I changed out my lifters, push rods, and rocker arms. After putting everything back together and running it for about 20 min I changed the oil. Then the ignition problems started to surface. The ignition system wiring is not my strong point and I need help.

This jeep has had loose wires and vacuum hoses for a while because my father and a few shade tree mechanics took off the emission control stuff about 20 years ago. I tried to pay close attention to the wiring for the coil, distributer and all but must have missed something.

I know there are lots of posts on this issue and I have read through many of them to get a good idea of what my problem is. However, after trying several things and replacing the coil and control mod, still no spark.

COIL I tested the spark from the coil by pulling the coil wire from the distributer and checked for spark by leaving a gap between wire and ground and MO SPARK. I replaced the coil because the old one was damaged (big dent in the side) about a month ago when the battery fell off the shelf and down beside the coil and distributer. still no spark.

Coil wires connector The wire connector that is plastic and clips to the top of the two coil posts was the original one and was actually broken. Replaced it with a new one from NAPA. Still no spark


Connector wires for distributer I found that two of the three wire on the distributer side of the connector where breaking off at the connector. I temporarily connected the directly until I can get a replacement part. Still no spark

Control Module I checked the control mod on the driver side fender and it was fried. I do not know how long it has been like this or what caused it. I replaced it and still no spark. I'm concerned that my root problem may have fried the mod and simply replacing it could damage the replacement.

Loose wire / where does it connect? One problem I know I have is I have one wire that I believe should be connected to one of the coil wires but I'm not sure. I appears to be dark green and has what looks like a resistor on it. I have looked back at some of the pictures that I took before working on the lifters and unfortunately could not find where it goes.

Where should I start with the testing to get things back up and running?

2014-05-23-15.55.52.jpg   2014-05-23-16.04.49.jpg   2014-05-23-15.57.20.jpg   2014-05-23-15.58.09.jpg  
2014-05-23-15.52.44.jpg

2014-05-23-15.53.22.jpg

rcrayne is offline   Reply With Quote
Unread 05-23-2014, 07:04 PM   #2
JeepHammer
Running On Empty...
1973 CJ5 
 
Join Date: Aug 2007
Location: South West Indiana
Posts: 9,952
Take a good look at the diagrams below...
And if it were me, I'd trace every wire in your ignition harness to make sure they are going where they need to be,
That they have solid connectors and connections,
And I'd have a look to see if the wiring were pinched, rubbed through or melted anywhere.



------------------------------

One thing I see right away is the 'Ground' wire for the module goes through the distributor housing.
The 'Black' ground wire for the module is cut and hanging in space in the bottom picture.

I *Think* the 'Where does this connect' wire/connector is the O2 sensor wire.
JeepHammer is offline   Reply With Quote
Unread 05-23-2014, 09:22 PM   #3
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Thank you jeephammer. I've seen those diagrams on other threads before. However, this time I looked at it I noticed #8 in the bottom section. I think this is the wire I'm tracking down. Just weird that it is green, I thought most green wires are ground. I will be tracing and checking them all tomorrow.

As for the ground (black) wire from the distributer is actually still conected through the connector. Only thesheilding is gone right up atthe connector exposing the copper wire. Just hard to see in the picture. I think I will go ahead and cut out the connector and just conect it to the distrbuter directly like I did the purple and orange ones (temporarily).

thank you for the post. I will post my progress tomorow.
rcrayne is offline   Reply With Quote
Unread 05-23-2014, 11:56 PM   #4
Unretarded
Member
 
Unretarded's Avatar
1963 CJ5 
 
Join Date: May 2014
Location: Ventura, Ca
Posts: 229
I hope you get it tracked down!


Just thought I would mention this for your sake and others that might read this.......when I see those crimp connectors I cringe.......if they are not crimped tight enuff, bad contact, if crimped too tight you cut wires and only a few strands connect....bad contact......they trap moisture and corrode, bad contact......see a pattern here....bad contact.

I have tried to spruce them up before inside with dielectric grease before crimping etc.....but even then, you still just can not see in them good enuff to tell if you have bad contact, corrosion etc.


Plus they just kind of look bad when you see a lot of them every where under the hood.

A good solution which works perfectly and looks good, is to solder them with the correct non flux solder....preferably electronic silver solder, then take and coat with dielectric grease and finally slide a piece of heat shrink over the repair and shrink it down.....quality heat shrink makes a difference too.

This makes a world of difference.......full contact of the wires is achieved, dielectric grease sort of protects the bare wires and the heat shrink seals out the moisture............it works good, looks good and lasts.

The heat shrink comes in a few different colors also allowing you to sort of color match the wires.

Doing it this way ends up with pro job, looking good and is a lasting repair you will not have any troubles with.

Short of replacing the entire wire length.....which is not possible sometimes or a new part harness........the method outlined above will yield the best results.

Not mandatory and there is certainly no shortage of those connectors on wires and for the most part work acceptable , for a time,....but are definitely prone to failure at some point....sometimes years, sometimes weeks, sometimes minutes.
Unretarded is offline   Reply With Quote
Unread 05-24-2014, 12:45 AM   #5
BagusJeep
Web Wheeler
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali, Indonesia
Posts: 4,268
Your wiring is a mess and you seem to have a terminal ICM. Apart from that it should all work, this is pretty common.

As well as checking the wire routes you need to get yourself a 12V test lamp and some long leads. You can use this to check for voltage and grounds and work through the system. If you also have a resistance meter you can check the sensor wires have about 650 Ohms and the continuity and resistance of the coil.

Also be aware the sesnor wires are supposed to conect one way only, if you swap the wires you will get problems as the sensor will not sense properly.
__________________
BagusJeep lives in Bali, the Land of Temples.
With a Jeep every prayer counts.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline   Reply With Quote
Unread 05-24-2014, 06:28 AM   #6
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant, Nova Scotia, Canada
Posts: 11,980
Have you checked the ign/lps fuse? It is on the lower right of the fuse panel, second up from the bottom.

Your fried ignition module can happen from leaving the key on to say, listen to the radio or troubleshoot.
__________________
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
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
Mike Romain is online now   Reply With Quote
Unread 05-24-2014, 06:34 AM   #7
orange150
Registered User
1982 CJ8 
 
Join Date: Apr 2014
Location: Raleigh, NC
Posts: 75
Quote:
Originally Posted by Unretarded View Post
Just thought I would mention this for your sake and others that might read this.......when I see those crimp connectors I cringe.......if they are not crimped tight enuff, bad contact, if crimped too tight you cut wires and only a few strands connect....bad contact......they trap moisture and corrode, bad contact......see a pattern here....bad contact.
One tool that has been a huge help with crimping are ratcheting crimpers. They ratchet down and won't release until the appropriate amount of pressure has been applied. I hate wiring so these things have been worth every penny.
http://www.toolaid.com/content/profe...rminal-crimper
__________________
'82 CJ-8
258/T5/D300
AMC 20/D30
orange150 is offline   Reply With Quote
Unread 05-24-2014, 07:58 AM   #8
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Thanks to all the post's.

Unredtarded -My plan is to clean up the wiring mess unter the hood after I diagnose what's wrong and get it repaired. The connedtors I am currently using are temporary. I plan on using the shrink and better crimps at that point. I didn't want to go through the extra time and expence at this point only to have to cut it back out and do it again later.

Mike- Thanks for the sugestion about the fuse. That will be ther first thing I check this morning.

More to come today as I work through this. This forum is awsome! Kinda like the"jeep wave", it's nice to know how jeepers help each other out in a time of need.
rcrayne is offline   Reply With Quote
Unread 05-24-2014, 09:49 AM   #9
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Ok, update time.

Ign/lp fuse in fuse box ok.

I downloaded and printed the shop service manual for my jeep. I am workin through the ignition system testing startin on pg C-62.

Results so far.

step 1 - key on- voltage from positive on coil to ground on battery - 12.86 (bat voltage) - voltage NG - go to step 4
step 4- key on- disconect starter motor solenoid I-terminal - observe voltage at pos coil terminal - 12.74 (bat voltage) - voltage NG
step 4 ( continued) - connect jumper between coil neg and ground- 12.16 volts. Drops but not 6+/- 5v. - NG - vo to step 6 test resistance wire.
step 6- turn key off- check resistance- connect meter between coli positive and dash connector FW . This is where I am stuck.

what is the dash connector FW?

Your top diagram also shows a "ingnition resistor" on the red wire between the coil positive and the ignition module. The botom diagram shows a " resistor (potor wire) " between the coil positive and the red "harness power connector" and the splice to the ignition source from key switch.

I need help verifying the resistor wires. Is it the green wire with the black plastic thingy on it? At this point I have confirmed that the wire with the disconnected end in my above picture leads up into the harness and to the #2 connector (14b lt. Blue 14ga) at the control mod. So I guess the wire that is still loose is actually light blue, with years of grease and heat changed to look green on that end. Should this wire be attached to the coil positive terminal? Should it be spliced in red wire between the positive coil terminal and the red wire from the starter selenoid? Although this may not resolve all my issues, I think if I get this wire connected properly, I can move forward.
rcrayne is offline   Reply With Quote
Unread 05-24-2014, 10:05 AM   #10
Matt1981CJ7
Web Wheeler
 
Matt1981CJ7's Avatar
1981 CJ7 
 
Join Date: May 2011
Location: Elbert, CO
Posts: 9,890
Dash connector FW. Also known as "firewall connector". FW describes which terminal to check.

Matt
jeepcjfirewallconnector.jpg

Matt1981CJ7 is offline   Reply With Quote
Unread 05-24-2014, 10:46 AM   #11
Mike Romain
Registered User
1986 CJ7 
 
Join Date: Nov 2007
Location: Off the Grid in Chester Grant, Nova Scotia, Canada
Posts: 11,980
If you have 10 -12 volts on the coil positive with the key in run, consider step 6 passed.
__________________
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
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com (10 new albums added Sept 16/10)
Mike Romain is online now   Reply With Quote
Unread 05-24-2014, 10:47 AM   #12
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Thank you Matt, I've been tracing back all o the wires through the harness. This helps
rcrayne is offline   Reply With Quote
Unread 05-24-2014, 10:55 PM   #13
BagusJeep
Web Wheeler
 
BagusJeep's Avatar
1981 CJ7 
 
Join Date: Jul 2009
Location: Bali, Indonesia
Posts: 4,268
Quote:
Originally Posted by rcrayne View Post
Ok, update time.

Ign/lp fuse in fuse box ok.

I downloaded and printed the shop service manual for my jeep. I am workin through the ignition system testing startin on pg C-62.

Results so far.

step 1 - key on- voltage from positive on coil to ground on battery - 12.86 (bat voltage) - voltage NG - go to step 4
step 4- key on- disconect starter motor solenoid I-terminal - observe voltage at pos coil terminal - 12.74 (bat voltage) - voltage NG
step 4 ( continued) - connect jumper between coil neg and ground- 12.16 volts. Drops but not 6+/- 5v. - NG - vo to step 6 test resistance wire.
step 6- turn key off- check resistance- connect meter between coli positive and dash connector FW . This is where I am stuck.

what is the dash connector FW?

Your top diagram also shows a "ingnition resistor" on the red wire between the coil positive and the ignition module. The botom diagram shows a " resistor (potor wire) " between the coil positive and the red "harness power connector" and the splice to the ignition source from key switch.

I need help verifying the resistor wires. Is it the green wire with the black plastic thingy on it? At this point I have confirmed that the wire with the disconnected end in my above picture leads up into the harness and to the #2 connector (14b lt. Blue 14ga) at the control mod. So I guess the wire that is still loose is actually light blue, with years of grease and heat changed to look green on that end. Should this wire be attached to the coil positive terminal? Should it be spliced in red wire between the positive coil terminal and the red wire from the starter selenoid? Although this may not resolve all my issues, I think if I get this wire connected properly, I can move forward.
So far you have established only that you have battery voltage at the coil +ve (positive for you septics) in On. This means you have voltage but you do not have a resistance wire. It would be in that red with tracer wire leading to the coil. You do not have one.

The only light blue wire is the Starter wire, live in Start only. This goes to the solenoid S tab and the module 2 way plug.

Here are a few diagrams that may help understanding.

The Duraspark II diagram is a generic Ford diagram, your will have adifefrent cap and the layout of the wiring is as per the ignition schematic.

the ignition schemaic is pre-Nutter so the sensor goes to the computer. If the computer i sinoperable no signal will be recived by the ignition module.
84-86fuseboxsch-copy-2-.jpg

schematic-ignition-layout.png

durasparkii.jpg

__________________
BagusJeep lives in Bali, the Land of Temples.
With a Jeep every prayer counts.

1981 CJ7 258ci - Bagusjeep
1984 CJ7 258ci - Puthijeep
1981 J20 258ci - Gladys
1995 Cherokee 4.0 - CHEROKEE
BagusJeep is offline   Reply With Quote
Unread 05-25-2014, 10:05 AM   #14
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Up and running. Will post details later today.
rcrayne is offline   Reply With Quote
Unread 05-27-2014, 10:45 AM   #15
rcrayne
Registered User
1984 CJ7 
 
Join Date: May 2014
Location: jacksonville, florida
Posts: 9
Update time.

First of all thanks to all of the help from those of you in the forum, we are back up and running and feeling pretty good about my wiring now.

This is a few of the things that I found and fixed through the process of verifiyng each wire's routing and connections.

One thing that I would recommend to anyone reading through this thread in seach of help for their project is take the time to check each wire and connection in your ignition system yourself. Especially if you are not the original owner. Although I thought I knew more about my jeep's mechanical history because my father was the original owner and I have been involved with what I thought was most of the repairs over the years. However, through this process I found out otherwise. Evidently my father had a few buddies that were self proclaimed mechanics that like duct tape for connecting wires, LOL!! Although it may seem like a lot of ectra work, I should have done this from the start. It would have saved me a great deal of time and it will help you feel more confident about your work when finished. It also will force you to learn more about what things are under teh hood and how everything interacts together to give you that AWSOME JEEP EXPERIENCE!.

To start with, after all of the above posts and trials, I opened all harnesses to expose all wires and connections. Some wires went into the harness one color and due to a past shadetree splice, came out the other end another color. When I started seeing this, I decided to check each wire and connection in the entire ignition system.

My final repairs and installations were as follows.
1) For each connection or splice that I made I used a socalled "weather proof" crimp connector that has the heat shrink on the outer casing. I put dielectric grease in each connector, made a solid crimp, then heat shrink.
2) Replaced the original coil with a Accel Super Stock Coil from Advanced Auto ($35.99). I decided to go with a coil that has the nut & bolt connector type in order to eliminate the stock, slip on type connector. I put the dielectric grease on each of the terminals before connecting to help deter corrosion at the coil terminal.
3)I replaced the original distributer connector (BWD Distributor Ignition Pickup -Advance Auto $27.29) because two of the wires broken off at the female connector.
4) Replaced the original control module with the direct replacement (BWD Select Ignition Control Module - Advance Auto $35.99)
5) Replaced the Ignition Control Module Connector because one of the four wires to the connector was broken off and spliced around the connector. (BWD Ignition Control Module Connector - Advanced Auto $17.99)
6) Added the recommended additional direct ground to the black ground wire between the distributer and the control module.
7) Replaced the resistor wire (potor wire) between the coil/solenoid spice and the ignition switch/control module splice. Checked resistance and is fine now.
8) Retested each wire and connection individually again for correct voltage or resistance before attempting to start the engine, (cranked just fine).
9) Reused some existing split wire harness and added some knew. I wanted to eliminate as much of the electircal tape wrapped harness as possible. It looks better and is easier access for future work.

Once again, Thank You to all that provided the expert advise.


All seems to be well now as for my wiring under the hood. Although this project has lead me to start on the dash wireing as well. I have lots of things to work on there. Starting with the gas guage not working. Will start a new thread for that project soon.
rcrayne is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.