cbwymore,
Yup, that was the solution, to change the oil pump drive.
If you can get the engine to TDC on the compression stroke, it will be the safest way to make sure everything lines up for the swap. You can do it with the crank anywhere in its cycle, but you need to carefully note the position of the shaft on the old part before you take it out. The drive has a pin hole in the housing and the internal half-moon sheild. With a punch or toothpick through those holes and the engine at TDC, the drive should almost drop right in. with the notch for the sensor at at the rear. Keep in mind that the heilical cut in the gears will require a slight twist as the drive drops down. You have to twist it the opposite way before hand so that the sensor notch points to the rear when the drive drops down. If you don't account for this, the drive will end up one tooth off. One more thing, the end of the drive drops into a slot on the oil pump. If these don't line up, the drive won't drop down all the way. Pull out the drive, use a long screwdriver to tweak the position of the slot, then drop it back in. I had to do this a few times. If you've ever worked with an old distributor on just about any vehicle, this is exactly the same thing.
So, the odd part was getting it dialed in. I had to guess where to position the notch in order to start the engine. I used the markings made by the hold down clamp as the oil pump drive slipped in order to guess how far back to turn the new drive as compared to the old one. If you found TDC exactly, you should be able to use the holes and a punch or toothpick to eliminate this guesswork. I started the engine, loosened the clamp, and twisted the drive until the engine ran right (just like timing with an old dist and no computer). There wasn't much play, a little too much one way or the other and the engine ran like crap or died. When it was spot on, the thing ran like a top. Rev the throttle a little after each adjustment to see if you have it right. Mine idled fine but couldn't rev up at all if the adjustment was off in the slightest.
I left the batt cable off last night and today I have no codes. I'm pretty sure it's perfectly fine, but I don't wanna drive it far until I have the dealer do the "fuel system sync" with the DRBIII scan tool. I'll update Weds night with the results of that.
One of the things that baffled me was that so few people reported this. Then I realized 2000 was the first year for the DIS, prior to that it was all distributors. I searched today and found that seizing distributors are a little more common, but not as common as crank pos sensor. It made me feel a little better that its not something else wrong with my engine that may come back to haunt me next week. I then disassembled the old pump drive tonight. With the roll pin out, the gear slid right off and the thrust washer looked good. When I tapped the shaft out, the upper bushing came out with it, it was really tight on the shaft and may have rotated in the housing. The lower bushing was fine. The shaft has a spiral slot to help oiling the lower bushing. There is no provision for oiling the upper bushing. There were bits of bushing strewn about inside the housing. What a silly design. I would like to have taken the new oil pump drive apart and had the upper bushing treated with some sort of tfe coating, but I need to get this back on the road and I am tired of working in the freezing garage. Maybe I'll get another one of these 80k miles from now, treat it and replace the one on there now
Oh, lastly, for posterity, I had birds chriping under the hood early last week. Noticed it two days or so before the "event". It happened when cold and went away as after just a few miles. I figured it was just the belt tensioner. Searches on failed distributors revealed that similar squeaking preceeded those failures, too.
Hopefully my adventures will help you save some time getting your XJ back on the road! Good luck.
Mark D.
