Old Jeep fun | TexAgs

whoop_2004

Joined: Jan 30, 2007

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So a few weeks ago my 81 CJ-7 died at a light. Was acting like a dead battery but luckily a nice fella stopped and helped us push it so I could pop the clutch. Finished our errands, stopped for lunch and she fired up no problem. Get home and about an hour later go to move it back into the backyard. No start. Jumper box didn't work, jumping off my truck didn't work so I used the winch to drag it into the backyard.

Starter ended up being bad so I replaced that and she cranked strong but wouldn't fire. Ignition coil tested bad so I decided it was a good time to upgrade to HEI.

About a week later I Get it dropped in hooked up yet she wouldn't fire. This afternoon I pulled the valve cover off and I think I found the issue…apparently Bluetooth pushrods do exist! Anyways made sure none were bent, and torqued the rockers down. Probably a collapsed lifter? She fired right up and idled smooth after I put it all back together.

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EskimoJoe

Joined: Oct 28, 2010

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12:33a, 4/27/25

Drop the oil and look for glitter. Cut the filter open and do the same. You could have a cam lobe going flat.

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whoop_2004

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2:08p, 4/27/25

Drained the oil and cut open the filter this morning. No sparkles thankfully. Took the valve cover back off and going to remove the rockers and pushrods to see if anything obvious stands out.

Burdizzo

Joined: Oct 11, 1999

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9:20a, 4/28/25

AG

That is weird. Usually they make a hell of a clatter when they throw a pushrod, and four lobes going bad simultaneously is not something you hear about often. I am baffled how an engine would throw four pushrods at once

whoop_2004

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11:30a, 4/28/25

I'm really leaning towards my timing chain jumped a few teeth….the mystery deepens

Centerpole90

Joined: Dec 12, 2003

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9:43p, 5/5/25

AG

Have we done any work on this? I'm curious what the culprit was.

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whoop_2004

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9:52a, 5/6/25

After getting the motor to TDC I discovered that my timing mark was at 8 degrees AFTER top dead center. Popped off timing chain cover to find a very stretched and worn timing chain that had definitely jumped a few sprockets.

Waiting for some free time to change this out and hopefully that will be that.

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Centerpole90

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In reply to whoop_2004 • 7:25a, 5/7/25

AG

Awesome. I'll doubt that's an interference engine, and I'm sure you'd have been alerted at a clatter; you should be 10/10 with the new timing chain.

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whoop_2004

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5:19p, 5/15/25

Finally got it put back together and it's amazing what a difference a new timing chain makes. Here's a photo of the old one compared to the new one. Hard to see the broken nylon teeth on the sprocket.

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