So i finally managed to check the timing with a timing light. Its more or less at zero.

I forgot to mention in my initial post that i also replaced the timing chain a year ago and that did not solve the problem. Tooth picl test at distributor is okay so i assume the chain is okay.

Was also thinking about the exhaust manifold. Will test this with a leaf blower next weekend.

Something strange that i recognized today is that it got slightly better. The only thing that changed is that it is getting colder where i live. Outside temperatures are dropping to 7 degrees C.

Regards,
Johnny

 

Wanted to give an update after endless hours of searching for the root cause and swapping parts.
I came across another post in this forum that mentioned the seals of the throttle shaft bearing. Checked that, bearing seal was completely brittle and came apart on disassembly.

Ordered new bearings and installed them. Problem solved.
By the way. The original manufacturer of those bearings was SKF. They are out of production. The ones you find on ebay are most likely 20+ years old.
Koyo Bearings still produce this bearing under a different Part Number. Its a direct fit: KOYO JTT67

Lessons learned. Try to find the root cause before firing the parts canon (if possible...)

Thanks to all you guys in the forum. My jeep runs fine again.

Regards,
Johnny

 

Good fix, it reminded me of reading about it long ago. Pretty good how that ever was discovered to be the cause. Reminds me of my trying to find the cause of a slight intermittent little stumble at idle.

Did you replace the bearing or did you do the o-rings thing?

 

I installed new bearings. Did not trust to use O-rings as a dynamic seal. The Koyos work nicely.

You need a needle bearing remover tool to get out the old ones. The new ones go in easy if you have a press. I went to a machine shop and gave them 10 bucks to do that.

 

And thanks for coming back aftrr all time and letting the thread know how this ended 👍🏼. Too many threads have no closure..

 

Nicely Done!! Thanks for posting the part number!!