Distributor Problems

[Ryank]

Hi All, Thanks in advance for any input / ideas you might have.

Sometime in January my '97 TJ was sitting in the driveway running, my brother says he heard it rev up and then a pop happened. ( Wish I was there to help describe it better) And, that was that, it wouldn't start at all.

My dad is pretty handy when it comes to this kind of stuff so he did a lot of reading and came up with a game plan, he removed the head cap to make sure everything was functioning properly and all is well. Next we checked the distributor, we pulled it out and about half of the gear had been ground down to nothing.

So, we go get a new one from Advanced Auto, replace it (made sure timing was all good), and boom, jeep works again. It would backfire here and there I just thought maybe the gas had turned, or maybe the fuel pump wasn't working properly. I drove it for about two weeks like this, It would run fine, then hit a deadish spot (spit and sputter) then continue driving just fine.

Then, one day in the middle of an intersection the jeep decides to die on me. I can't for the life of me figure out whats going on. I let it sit a while and then it starts again, we get it back home and let it sit. Dad thinks maybe he didnt seat the distributor right. We go to remove it and it won't pull out easily, we almost needed to pry it out.

I wish I knew the correct terms, but the washer tabs were bent down onto the gear, so we think ok, bad part, take it back, replace it, install it. Back in business. I drive it 12 miles and this time it completely dies no restarting this time. We tow it home, go to remove the distributor and the same thing has occurred.

I'll upload a pic of what I'm explaining. If anyone has any ideas I'd really appreciate it!

 

[Jeep9748]

I replaced the distributor in my 97, mine was a problem under the cap and rotor. If you remove the cap and rotor and the electrical components, you will see a bearing. mine was gone so the shaft wobbled and was horrific. just a thought. Also look into the distributor switch plate. Lastly, as I know you are installing it correctly, did you happen to ensure nothing fell into the hole while the distro was out. Good luck

 

[Jeep9748]

And when you reach your limit of IDK's....I remember ALONG time ago when I worked at an auto parts store, sometimes the store would get a bad batch of parts all the same type. The last one I dealt with was a shipment of Batteries that were all bad. I want to say the count was 75 batteries. So I guess I am saying that if you are distributor number two, and they are the same brand, return and get a different brand.

 

[Ryank]

And when you reach your limit of IDK's....I remember ALONG time ago when I worked at an auto parts store, sometimes the store would get a bad batch of parts all the same type. The last one I dealt with was a shipment of Batteries that were all bad. I want to say the count was 75 batteries. So I guess I am saying that if you are distributor number two, and they are the same brand, return and get a different brand.

Thank You, I appreciate the input. We will check things out. A different auto parts store had two different distributors for the same model. Maybe this is in fact the wrong one?

 

[radmon]

OK, everyone listen up, just went through the trouble of registering to drop a secret knowledge bomb for you that I attained after a epic battle with a 1989 Wrangler. Yes that's a bit dramatic but if you knew how long I hunted for the source of the problem before I got this simple epiphany you'd understand.
I was experiencing symptoms just like Ryank. I changed carbs multiply times, changed the dist., did the computer lockout, adjusted valves after assuring they all were working properly, even scoped the cylinders. Nothing worked. Sometimes it would run great, sometimes it was crap. It was a multi-personalitied demon bastard.
Then it hit me. I checked every aspect of timing except the one very few people think to check, the timing chain. A sloppy chain, if you think about it, will bounce around from leading to lagging depending on crank acceleration and deceleration, cam and valve train inertia, how much valve spring tension there is against either the front or back side of the lobe. In other words, lots and lots a variables, hence the erratic behavior.
So yeah, keep your chains tight boys and girls. You can check for a loose chain by turning the engine by hand one way then the other. Pull the cap and watch for rotor lag and feel for changes in the force needed to turn the engine. Compression and valve load will cause gradual increases or decreases in that force but a timing chain change will be more of a distinct thunk and you'll feel it in both turning directions and with equal, consistent distance. It'll usually be within just a few degrees of rotation. Also, with a timing light, look for fluctuations. your timing should advance smoothly and return steady when you rev the engine.
After I changed the chain in my Wrangler, it ran terrific. Especially since everything was optimized while looking for the real problem. In fact, the guy I sold it to said it was easily the best running, fastest I6 jeep he ever drove or rode in. It idled perfectly, had lots of off line acceleration with 33's and 3.73 gears and had no problems passing on the interstate.

 

[Ryank]

Very interesting radmon.

I ended up purchasing a 98 motor. Dropped it in and now I can't get that puppy to run.

But, the reason I did this is because a mechanic told me that the camshaft was no good.

Im curious now to find out if the chain was in fact loose on my 97 motor.

Thanks!

 

[radmon]

Since it’s easily accessible, pull the timing cover and visually inspect it. It should have very little slack if it’s good.
I to suspected the cam in mine till I pulled the valve cover and measured how far each valve was opening.