While driving the engine started to cut out some at higher speeds then after awhile it just died. So there I am stuck on the side of the road thinking I have a fuel problem. Fuel flow checks good. Spark checks bad. After replacing coil still not working correctly.
12v to starter solenoid
7v out of solenoid and to coil in run position
9v out of solenoid and to coil in start position
when cranking no spark until you release ignition tumbler then I get one lously spark. Gives half a sputter then nothing.
Could I have a problem with my tumbler or ignition pack/module?
how should I proceed now?
Nutter'd ? Thats where I would begin, Computer could be screwing things up. Then after all this, I would look into the Control Module over on the driverside fender below windshield wiper fluid filler. I have the same year jeep, and this is how it acted before I nuttered it and put a new control module on.
OK, I've posted this several times, but there is a new crop of 'Ignition Help' threads again, so I'll throw it up again...
First off, you need a TEST LIGHT.
Volt-Ohm meters don't load the circut correctly, so you can't test to see if the resistor wire built into the ignition circuit is working.
A cheap test light will load that resistor, and give you accurate readings.
Test light runs about $6 at the parts store,
Looks like an ice pick with a light bulb in the handle and a wire coming out the top.
Connect the wire (alligator clip) to the battery NEGATIVE first.
Pull off the coil connector.
Test the terminal in that coil CONNECTOR 'Red' wire.
(not the coil, which should now be unhooked)
With the key switch in the 'Run' position,
You should get a 'Dim' light.
That tests the ignition fuse, factory tach, ignition switch, and the wiring to the coil.
With the key switch in the 'Start' position,
You should get a BRIGHT light at the tester.
This tells you the jumper 'Start' circuit from starter relay (Solenoid) to the ignition coil is working correctly.
That one test tells you what side of the ignition the problem is with, Key switch side or the actual ignition side.
Now, connect the tester to the battery POSITIVE post.
Probe the 'Green' wire terminal in the coil connector,
You should get a steady 'On' bright light.
If you do not,
The module probably isn't getting 'Ground'.
Probe the 'Green' wire terminal in the coil connector while someone cranks the engine.
You should get a FLASHING bright light.
If you DO get a flashing bright light, you probably have a bad coil, bad coil wire or burned up cap/rotor.
If you DO NOT get a flashing light while cranking,
Then the problem is probably a fried ignition module,
But could also be the trigger in the distributor,
Or a break in the circuit somewhere between distributor and module.
Reconnect the coil,
Take your tester to the ignition module connectors.
These will be on the back side of the drivers front fender,
Under the washer tank.
Disconnect the TWO WIRE connector.
Module side should have a 'Red' & 'White' wires,
Harness side should have a 'Fat Red' wire and a 'Blue' wire.
Stick something in the slot on the HARNESS side so you can test the Harness terminals.
When the key is in the 'Run' position,
You should get a 'Bright' light on the 'Red' wire.
When the engine is cranking, key switch in the 'Start' position,
You should get a 'Bright' light on the 'Blue' wire.
If you fail either one of these tests,
You have a wiring issue.
Now you are down to a 95% chance it's the ignition module gone out on you, which is VERY common.
To test the distributor trigger (Stator),
You test the parallel terminals in the distributor plug.
You should show 400 to 800 Ohms resistance,
With about 625 Ohms being pretty standard.
Then test between one of the parallel terminals and the distributor housing.
Should show 'Open' circuit or Zero Ohms.
Do the same with the other parallel terminal and should show same results.
If there is ANY Conductivity between the parallel terminals and 'Ground', then replace the trigger stator.
I have directions and pictures of how to do that if it turns out to be the stator.
Now you are down to the Module or the wiring between distributor to module.
Take your module out and have it tested, or just get a new Borg Warner unit with lifetime warranty.
Don't forget to use a marker and mark down where and when you purchased it.
Makes things MUCH more simple if it goes out again.
If the new module still doesn't do it for you,
Then get back with me,
I'll post up a diagram of your ignition wiring harness and how to test the harness for defect.
Also be advised,
Due to a quirk in the Jeep/Motorcraft ignition system, you MUST NOT leave the key switch in the 'Run' position when the engine IS NOT RUNNING!
If you do, you WILL Smoke the module.
If you need accessory power with the engine off,
Then use the key switch 'Accessory' position.
If the engine isn't running, the module WILL smoke in a pretty short period of time...
Wish i could do an awesome write up like Jeephammer, your an awesome dude. I can just hit and miss, which is fine with me, I am sure the parts need to be replaced anyhow, and with jeeps we just collect parts some working some not. Makes good for spare parts to take on excursions and what not.
Lol, yeah I am by far not rich, and have went weeks at a time driving a limp vehicle. Usually I can educated guess right, lucky I suppose. But never had the pleasure of being in a post with the famed JeepHammer. Have read all your posts to the umph degree and did them according how you said, and argued with locals about your upgrades and how they think they are pointless, but I can tell a difference.
If your ever in the Chelsea Oklahoma area, I will buy you a beer sir fyi
I appreciate your help! I have read through a few "ignition problem" threads but I guess I missed this one. I have seen some similar problems but not this one. I'd have to tell you though that I am learning a lot and soon hope to be the guy with the answers.
Took me a year to learn a little bit, and what I have learned on the 80's modeled jeeps is Nutter, Control modules, and everyone on this forum is really nice and willing to help, and no one mocks for being a newbie question . I just went ahead and stripped my computer out of my jeep, and recently put in a fully rebuilt 79' style engine, because I got tired of leaky valve covers, sol-vac systems and that carter bbl.
Yup, AMC screwed a lot of things up,
But to own something that is so uniquely AMERICAN is worth the 'Education' (read: 'Azz Kicking'!) to get it working well!
It's like a Harley from the same era,
If it doesn't leak, squeak, rattle and refuse to run occasionally,
It's not a 'REAL' Jeep!
I had a guy in here, 24 years old, complaining about his Jeep not running correctly.
I worked on it for about two weeks lining out all the vacuum leaks, crap in the carb, worn throttle shafts, worn out ignition and all the other 'Issues' that go along with a '78 CJ that had been rode hard and put up wet down through the years...
He still complained about 'Sluggish' acceleration...
I took it out, did burn-outs on dry pavement and it seems very responsive to me...
Still complained about 'Sluggish' acceleration & 'Hard' starts...
So finally I had him take me out and show me EXACTLY what he was talking about...
He had never driven a carb before!
Didn't know you have to kick the pedal once or twice before you hit the key,
Didn't know there was going to be a hesitation when you mashed the throttle since it takes a half second for the fuel to reach the cylinders,
Didn't know that old linkages take some pushing to get the slop out of them!
Now he wants a remote starter like he's got in his car.
I draw the line at some sacrilegious things!
My GSX still has the factory Q-jet on top the Stage 1 455 engine...
I let him drive a CAREFULLY TUNED Quadra-Jet,
And he doesn't think his carb is that bad now!
Nothing like a Q-jet for giving you time to eat a bologna sandwich between the time you stomp it and it actually comes in and runs!
When it finally DOES come in, you had better be hanging on to something, but you get a coffee break waiting for the fuel to reach the cylinders almost two feet away from the carb!
If i am not mistaken then when I crank ignition I should get consistant sparks from the coil. I replaced the ignition switch and still I only get one spark when I release to the run position. Module and coil checked good.
Coil connector light does not change on red wire from run to start. (kinda in between bright and dim)
Found a loose wire from the 3 wire harness connection to module that was just hanging. Another wire hanging real close, hooked it back up and now I get the flashing bright light from the green wire in the coil connector.
from the module I checked the two wire connector and neither wire get a light while in start position. Red wire gets light in off position and blue wire gets light in off and run position.
I'm guessing I have a wiring problem. But what could it be? I was driving down the road and then a big gust of wind it me (thinking that was the final straw for the one the came disconnected) and jeep just died.
Thanks for your help guys, especially JeepHammer. I found the problem. Had a broken wire to the ignition module and after I fixed that I still had problems. I was working in circles but then found a bad solenoid. Guess I messed it up during troubleshooting....