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Electical problem

Electical problem

Alex

Jeeper
Posts
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Location
ontario canada
Vehicle(s)
1978 cj5 I6
I replaced the coil re-wired the engine to the basics and so far i only get the odd spark, turns over no problem distributer is clean but only sparks once when i try to start. im new with forums this is my first post any ideas would help!
Thanks
 
sounds like you got a little too basic, have you still got an ECM, engine control module?:cool:


I replaced the coil re-wired the engine to the basics and so far i only get the odd spark, turns over no problem distributer is clean but only sparks once when i try to start. im new with forums this is my first post any ideas would help!
Thanks
 
Yes the ECM is there still, i was wonder how often do they go bad? and is it possible to find replacements?
 
Yes the ECM is there still, i was wonder how often do they go bad? and is it possible to find replacements?


try smacking the module with the end of a screwdriver or LIGHT hammer...

Mine acted up on me last year, and I got it running by whacking it!!

Had to do so 4 or 5 times to get me home...

Now I ditched the module altogether....in favor of MSD... I got tired of it letting me down.
 
yea they go bad and you can still buy them , made in china. If you can swing an MSD box and a distributer upgrade it would be money well spent.:cool:
I am not going to say that this is the reason you won't start, if it ran before you rewired it it could be something entirely different.:D


Yes the ECM is there still, i was wonder how often do they go bad? and is it possible to find replacements?
 
I will try the small hammer, and i will look into the MSD ignition sounds more reliable and alot of ppl seem to do that upgrade. Thanks for the ideas
 
I will try the small hammer, and i will look into the MSD ignition sounds more reliable and alot of ppl seem to do that upgrade. Thanks for the ideas

Yes, but it isnt real cheap..
In a hurry, get the replacement module. I spent about $25 last time...

If not in a hurry and have the extra $$$, then go for it. It is not just a plug in replacement. There are quite a bit of wires that get removed, and re-routed. You shouldnt use the factory cap if you do the upgrade. Supposedly it is NOT a good idea. You need to go with the bigger cap...

BusaDave9 did a great writeup about it...

http://www.jeep-cj.com/forums/f2/teamrush-ignition-upgrade-11416/
 
Where would i find a replacement ecm, junk yards or store? I dont want to spend much on the jeep untill i know it will run and is worth the time.
 
just about any auto parts store can do it, there is a pick up in the distributer that will fail and do the same thing as well. just saying.:cool:
 
just about any auto parts store can do it, there is a pick up in the distributer that will fail and do the same thing as well. just saying.:cool:

Is there any way to diagnose the problem between the ecm or distributer? ecm is going to cost me 70$ distributer components about 40
 
I think the parts house can test the ECM.:D
 
So, i replaced the pickup in the distributer and the rotor because they looked like they needed replacing and still no spark at all, guess i have to bite the bullet and buy the ECM and try that? The auto parts place's say they cant test the ecm for me
 
Maybe I missed a post, but have you used a meter to verify that the coil, dist and ecm get 12v while the key is in the run position? I hate to see anyone just buying parts without doing a proper trouble shoot.
 
Maybe I missed a post, but have you used a meter to verify that the coil, dist and ecm get 12v while the key is in the run position? I hate to see anyone just buying parts without doing a proper trouble shoot.

Ya i used a test like to make sure i had power at the coil and before the ecm, just didnt know where to test after ecm. anyway to just bypass the ecm? My buddy has a amc 360 in his jeep and i didnt see an ecm
 
Ya i used a test like to make sure i had power at the coil and before the ecm, just didnt know where to test after ecm. anyway to just bypass the ecm? My buddy has a amc 360 in his jeep and i didnt see an ecm

Are you calling the Ford ignition module an "ECM"?
His 360 either has it, or some other aftermarket ignition...that is unless he converted it to a GM HEI distributor.
 
You can check you ignition control module with a test light, the kind that is sold at an auto parts store. Connect it to the battery positive and with the probe end, touch it to the green wire at the coil connector. Crank the engine and you should get a flashing light, if you don't, the problem is the module unless you have a wiring error. You can also connect the test light to the negative side of the battery and probe the coil red wire. You should get a dim light with the key in the run position and a bright light while cranking the engine. On the module look for signs of melted plastic around where the wires come out, if so your module is shot or going to be soon. With the engine running a bad module will be hot to the touch. A good distributor pick up coil should get 400-800 ohms at the orange and purple wires with a test meter.
 
Last edited:
If I could find my ecm you can have it. Or anyone else out there
 
the 77 and 78 have a "unique" ignition system It will be different from your buddy with the 360.:D
 
Replaced the ecm after testing off the coil and i now have spark and it fires just need to set the timing and work on the carb, thanks for the help
 

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