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Spark plug wires... Jeep wont start...

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Old 11-19-2010, 06:09 PM
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Default Spark plug wires... Jeep wont start...

Hey guys. So i did a tuneup several months ago. replaced the rotor and the cracked distributor cap. The oil soaked burned looking air filter with a dead snake in the box. All the spark plugs and wires. Well ever since i did that the jeep was backfiring. I simply tookt he new cap and switched one wire from the other cap to the new one then bolted it down so as not to mess anything up. Then moved onto the plugs. Stripped some plugs out had to get more learned im supposed to hand tighten them...luckily doesnt seem like i stripped out the threads on the engine. Anyways that backfiring thing isnt good for the jeep so i decided to try and redo it now that i had my haynes manual. Looking at the picture and the my jeep the order of the wires is friggin obvious. I mean theres now ay i could be getting it wrong.\

The first thing i noticed was the 4th plug wire was in the 1 plug wire spot. I switched those two and instead of backfiring it sounded like it was running alot better other than a loud knock from the engine....so i pulled all the wires and put htem in the manuals indicated spot. Now it wont start at all. Starter was spinning but then the engine made a sound as if it wanted to start but abruptly lost power and all the interior lights dimmed and then the process would repeat. After redoing it several times with the same results all i did was switch the 1 and 4 wires back again and it almost sounded like it was originally before i started this. However i cant get the engine to turn over. It just spins and spins the starter and you can hear it catch for a moment then goes back to starter spinning. And i could smell gas heavily under the hood. EVentually its gotten dark and way too damn cold... I really need help guys. WTF did i do?!
Old 11-19-2010, 06:40 PM
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I know its a thick read guys but please... I really need help here.
Old 11-19-2010, 06:54 PM
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Oh and its a 92 cherokee 4.0 automatic 2wd....
Old 11-19-2010, 06:58 PM
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Is the new cap you installed marked for the #1 cylinder?

Firing order is 153624 clockwise, double check this.
Old 11-19-2010, 06:59 PM
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Did you re-connect the line from the ignition coil to the center of the distributor cap?

And you drove around with it misfiring for a couple months?!?
Old 11-19-2010, 07:03 PM
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Yes the center wire is connected. I did not touch that wire from before. And yes i drove it while it was misfiring for a few months. I needed it running just to get to work and i didnt want to mess anything up like i have now.
Old 11-19-2010, 07:07 PM
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And it's firmly connected to the ignition coil? Also, replacing the ignition coil itself would probably be a wise idea. Most don't consider it, but you have to figure, it's seen just as much wear and tear as the rest of the system. Just a thought.

Is the new dizzy cap cracked at all? Even a hairline crack will allow it to arc. Best thing to do, wait till it's dark out, have someone try cranking the motor while you watch the dizzy closely. Any electrical short will be easy to see at night with no light.

Hope that helps!
Old 11-19-2010, 08:54 PM
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Ok, as it was running before it's most likely it's to do with some of the stuff you've been touching.

You said you got the wires/firing order correct, but it's very easy to get it wrong. Happened to me before as well. I'd also make sure the plugs are really sparking. Get yourself a little tester, or take out the plug, connect it to the lead, ensure it touches ground, start engine and see if you have a spark.

As you've been busy with the distributor cap, check a few things as well. Check if the cap sits properly on the distributor. Sometimes they don't sit completely straight. Take the rotor off and check the inside. There's some sort of small pin that fits in the rotorshaft to fix it in the correct position. You can check this also by trying to (carefully) twits the rotor. Also check for play in the rotorshaft. After years of use, the bearings wear out, meaning the rotor isn't going round in the correct position.

Check the inside of the cap. Any evidence of the rotor banging into it or the different contacts. That should indicate some of the above problems too.

Also, inside the cap should be some sort of spring loaded pin that presses on the rotor when you put it all together. Check it's there and there's sufficient movement. Without it you won't have a spark at any of the plugs.

Make sure all the leads are really clean, before you push them in the cap and or plugs, and make sure they are in properly.

All of the above are a few easy checks that shouldn't take more than 10 - 15minutes. Sort of my collective experience over the years of what can be wrong with the basics of the ignition system.

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Old 11-19-2010, 09:11 PM
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You said you have a haynes manual, follow the pics, if the wires are correct and you engine is running like crap, then its something else, you did say you ran it for a month or longer with it misfiring
Old 11-19-2010, 09:21 PM
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Right now im thinking ive flooded the engine with how much gas i was smelling. It got too cold and too dark to keep messing with it today. But tomorrow gonna take all the plugs out replace any that may need it. And follow the other suggestions here with some luck hopefully.

A friend of mine was saying the length of the spark plug wires affects things. All the spark plug wires are different lengths. Does anyone know anything about this?
Old 11-19-2010, 09:25 PM
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Originally Posted by OverlandXJ
Is the new cap you installed marked for the #1 cylinder?

Firing order is 153624 clockwise, double check this.
Thats that same as the manual says. And it shows the number 1 cylinder connector at the bottom of the distributor cap to the left of the bottom screw. The first cylinders spark plug would be closest to me standing from the front. Im about to get colored tape and take pictures just to get your guys opinions.
Old 11-19-2010, 09:34 PM
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like this right
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Old 11-19-2010, 10:49 PM
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Well, yes the length of the spark plug wires does matter to some extend. Some engines are much more susceptible to it than others. I've fiddled around with mine on my 98 XJ. Did not make a blind bit of difference. I've also got a 1982 Mercedes and there it is somewhat noticable.

I wouldn't think the wrong length to the wrong plug would prevent the engine from starting. At worse it won't run as nice or as efficient as could be.

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Old 11-20-2010, 12:45 AM
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Originally Posted by freegdr
like this right

Exactly.
Old 11-20-2010, 10:04 AM
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Just for giggles double check that you put the new rotor in before you dropped the cap on.

I'v done this.. and am man enough to admit it.


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