HELP My Jeep Wont Start

[Memphis77]

Ok,
So I have a 1977 CJ7 stock that I have had about four months . It has stalled on me a few times but then starts back up . About two weeks ago I took my wife for a ride and it was having a hard time moving and back fired then stalled . I went online and decided to replace the coil . After that it ran great for a few days then stalled after driving for about an hour started back up fine after a few Min.

Then this week I took it to the store and it started then ran rough stalled and has not turned over since. I replaced the ICM thinking that could have been the problem and it still won't start . It has new Cap , Plugs and wires . I smell gas when trying to start it but have not tested the fuel pump . It tries to start but it just won't turn over .

The jeep has a 258L six with a carter YF single and the original electronic ignition . Please help me get my jeep back on the road . O it was raining when it stopped working it that matters . I read online it could be a fuse but the post did not say what fuse . I don't drive the jeep in the rain and noticed I got water dripping behind the dash from the old cowl seal could that have blow a fuse ? I am not a mechanic but I am not afraid to pick up a wrench and try anyway !! I would appreciate any advise I can get . I plan on trying to get it back on the road this weekend .

 

[Lumpy Grits]

Clean ALL battery cable connections.
Clean and remount ALL ground connections on the engine, frame and body tub.
Try another battery--
LG

 

[jzak]

Ok,
So I have a 1977 CJ7 stock that I have had about four months . It has stalled on me a few times but then starts back up . About two weeks ago I took my wife for a ride and it was having a hard time moving and back fired then stalled . I went online and decided to replace the coil . After that it ran great for a few days then stalled after driving for about an hour started back up fine after a few Min.

Then this week I took it to the store and it started then ran rough stalled and has not turned over since. I replaced the ICM thinking that could have been the problem and it still won't start . It has new Cap , Plugs and wires . I smell gas when trying to start it but have not tested the fuel pump . It tries to start but it just won't turn over .

The jeep has a 258L six with a carter YF single and the original electronic ignition . Please help me get my jeep back on the road . O it was raining when it stopped working it that matters . I read online it could be a fuse but the post did not say what fuse . I don't drive the jeep in the rain and noticed I got water dripping behind the dash from the old cowl seal could that have blow a fuse ? I am not a mechanic but I am not afraid to pick up a wrench and try anyway !! I would appreciate any advise I can get . I plan on trying to get it back on the road this weekend .

On my last jeep, which had simular problems, it was the carburetor which was the issue, but before you try to rebuild that carb, you might want to look at switching out the fuel filter and pump. A bad fuel pump that works intermittently can cause a lot of the problems you mentioned.

Is it an issue that it goes from running great, to just cutting out completely? Or does it never run right?

 

[Torxhead]

I would think from your description that it would have been the icm, it could have been but anyway you not seem to have no spark, since you can smell gas when you try an start it. I think you should first verify that you have no spark then go from there.

 

[TeamRush]

Without putting to fine a point on this,

Diagnostics...

You don't know if it's wiring/electrical (Fuse),
You don't know if it's fuel,
You don't know if it's ignition.

This would be DIFFERENTIAL DIAGNOSTICS.

I'd start with a can of starting fluid.
A shot of starting fluid in the carb, then hit the key will tell you if it's fuel or ignition.

Staring fluid will fire with the SMALLEST spark happening, so if it fires, more than likey the ignition/wiring is working,
And you have a FUEL issue.

If it DOES NOT fire a lick with starting fluid,
Then you more than likely have an ignition issue.

This is a can of starting fluid and turning the key...

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

IGNITION,

Pull the coil wire out of the ignition coil.
Wire up a 'Test Plug',
Simply a spark plug with STRIPPED wire wrapped around the threads,
And the other end of the wire connected to the battery negative.

Have someone crank the engine.
The plug *Should* spark RHYTHMICALLY as the engine cranks.

If the plug DOES NOT spark, or only sparks ONCE as you turn the key switch off, then further investigation is needed...

SPARKS... Then you have an issue with coil wire, cap or rotor, Ignition isn't getting to the plugs.

Sparks only once when you turn the key switch off.
Trigger or module isn't working.
Firing the plug ONCE means the coil was getting power when the key switch was 'ON', but wan't getting triggered by the distributor trigger or module.

NO SPARK AT ALL,
Take the POSITIVE wire off the coil,
Get a test light, connect between WIRE and battery negative,
Turn the ignition switch on to see if you are getting power to the test light.

If not, possible fuse or ignition switch issue.

-------

Take your test light to the module 4 wire plug.
Test the 'Red' wire in the HARNESS side of the plug (testing an UN-Plugged module does no good, test the HARNESS)

See if you have power to that 'Red' wire when the ignition switch is 'On'.
If not, you have a power feed issue in the wiring.

If you do have power, it's time to get that module off the fender and have it tested or get another one...
It could also be a bad trigger in the distributor NOT triggering the module, this is common with a Prestolite ignition.

---------

TEST LIGHT CONNECTED TO BATTERY POSITIVE,
Then PROBE the single 'Black' wire going to the module.
If you DO NOT get a 'Light', the fender bolt has lost connection to 'Ground'.
(horrible way to try and 'Ground' the ignition through sheet metal with a rusty bolt...)

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

Once you differentiate between FUEL, IGNITION, WIRING then give what you found and we can track your progress and make suggestions on what next...

 

[BusaDave9]

Ok,
it started then ran rough stalled and has not turned over since.

the engine is not turning over? ?
When you turn the key does the starter turn the engine? If not you have a problem with the starting system. Not the carburetor. Not the ignition system. It sounds like it wasn't running very good before it died all together but now you have a separate problem; a problem with the starting system.
The starting system is very simple. When you turn the key a solenoid on the fender delivers battery voltage to the starter that turns the engine over. Those are the only components in the starting system.

We often get threads like this where someone doesn't explain the problem very well and everyone goes off on a tangent telling them to replace things that could never cause the real problem. Maybe I'm the one off on a tangent but I would like a little more clarification before I tell you to replace anything. It's these "engine not starting" threads that are the worst for people not communicating properly. That's why I created this thread: http://www.jeep-cj.com/forums/f99/engine-wont-start-troubleshooting-guide-19494/

My apologies if I am the one causing the confusion.

 

[TeamRush]

... It tries to start, just won't turn over...

I took that as 'Cranking' but won't 'Start'...

Cranking and won't FIRE, Fire before starting...

 

[CJBlues]

Thanks , I could not log back on so I created an new user . I removed the fuel line after the filter and I had fuel so that was out . I just replaced the battery so that was not the problem . I used a ignition tester it looks like a spark plug you connect the wire to it and crank the engine and it will spark it you got well spark . First I did it after the distributor and no spark so then I went to the wire from the coil to the distributor no spark . I just replaced the coil but decided to try the old one that was the original coil from 77 and bam spark . Hooked it back up and it started like a champ . So now I don't know if the ICM was bad and blew the new coil or it was a bad coil . The ICM was also the original I will keep the new one in and see if I still have the stalling issue . I did return the coil and got a new one different brand and will keep it in the jeep just in case .

 

[Torxhead]

If you have one of those slip on coil connectors, that could have been the problem, since they can loosen up and/or corrode. I think a safer bet would be a coil with bolt down terminals.