83 CJ7 Quit running on highway

[jeepwanabe]

1043404

Hi all,

I have an 83 CJ7 - Straight 6. I was driving last night and all of a sudden the engine quit running. I coasted to a stop on the side of the road and tried to figure out what was happening. When I tried to start it the engine turned over but no spark that I could see (I didn't hear any spark at all when trying to start). I checked the carb and I can see gas going into the carb. From here I don't know where to go. I suspect an electrical issue but I don't know the sequence of events to troubleshoot. For instance, what does the coil do, what is it's function and where is it in the sequence of events of a running engine. Is there some material out there which explains this? I have a Haynes manual but it doesn't explain the sequence of events and how they work. Can anyone help me with this?



TIA,



[addsig]

 

[RedWrang]

1043406

Try replacing the control module first. Only about 19.00 at Auto Zone. Its located on my 87 on the drivers side inner fender under the windshield washer bucket. Every Jeep owner I know carries a spare even me. Hope this helps out.[addsig]

 

[jeepwanabe]

1043416

Would that be the same for a 83 CJ7? Do they also have control modules? What function does this control module have?





Thanks,[addsig]

 

[berettajeep]

1043446

you should have a control module,the key word being should.

Did you check to see if the coil power wires were still attached?That happened to me,I was driving down the road and the jeep cut out,after a few swear words,I popped the hood,looked around and saw that the coil wires had fallen off.I hooked them back up and it started.[addsig]

 

[jprtroy]

1043471

No spark= no juice to coil. The coils function is to amplify battery voltage up to 25,000 to 40,000 volts. (somewhere in between) The disribuator's function is to distribuate the spark energy from the coil to each of the spark plugs. It does that through the dist. cap, rotor and wires. The rotor is what actually spins inside the cap, and as it spins, a metal blade on the rotor comes into close proximity of a post that has individual plug wires pluged on to it. The spark is then transmitted to the post, down the plug wires, to the spark plug.

The distributor is rotated by a gear on the camshaft located in the engin. (timing)

Now, the initial voltage that's sent to the coil comes from an ECM (electronic control module) or control module, or some other name. You'll have one trust us. If it's gone bad, no signal out to coil, means no spark out to the plugs, means, engin no fire. Is this all that can be wrong? No. The coil could have gone bad. A way to check to see if the coil has gone south is to measure voltage on the wires that go to to the coil when the ignition is turned on. If a voltage is present, (can't tell ya what that voltage is though) then, you should have a spark on the coil wire. If no voltage is there, then the ECM is probably bad. If you have voltage on the wires and NO spark on the coil wire, then the coil needs to be replaced.

The coils do go out, as do the control modules.

What else could be wrong? Well, until you can get a spark out of the coil, you can't do much more.



Chain of events: Turn key, Ignition is turned on, control module is activated, sends a signal voltage to the coil, the coil jumps that voltage way the hell up to a huge spark capable of igniting gasoline and knocking you on yer butt, then sends it via the rotor in the distributor cap to each spark plug, spark plug recieves the huge spark and ignites the air/fuel mixture in a voilent explosion contained in the cylinder, piston goes down and you move.

3 things are needed to make the motor run. Air. Fuel. and Ignition source (spark) any one of these things missing, motor no go bang!

Good luck, hope this helped a little.

[addsig]

 

[jeepwanabe]

1043518

jprtroy

Jeep Addict,



Thanks a lot. That helps a great deal. I'd really like some reference material on this and other subjects concerning jeep repair. Haynes is ok but could be a whole lot better in my opinion. How about the Jeep Shop Manual? I heard they are good. Can anyone comment on this? Any other references worth mentioning?



Thanks in Advance.[addsig]

 

[jprtroy]

1044058

I strongly recommend the jeep Technical manual, (shop manual) my ran me $90 many moon's ago (decades) Worth the coin's though. The hayns type books only touch on certine things, the rest is "left to teh factory" or sum such s#$%!

The Tech manual is what the factory tech use. The manual goes into detail on how to rebuild among things, the rear end, how to set the backlash, pinion depth etc.. what the tolerances are how to get them.

It contains "DAR's" Diagnostic and repairs has flow charts, block diagrams, shematics Basically tells ya how to rebuild/replace anything on the series of vehicles in the book.

Covers mechanical, electrical, drive trail, motor, body, fuel delivery, cooling, if it needs fixin, this book tell's ya how.

Don't expect your local stealer to have it in stock though, it'll have to be ordered. BE sure to ask for the TECHNICAL manual.

Good luck again.

[addsig]