Xj broke down while traveling

[Vitzaa]

Ya that's what I did. Set it to tdc compression and aligned the holes. Runs like crap, hesitating, rough idle, backfiring through intake with load... I rotated the shaft couple degrees clockwise and it doesn't start. Went counterclockwise from baseline and the same symptoms. Can't get it to run right at all. Spark plugs are fouled black

[Vitzaa]

I'm wondering if my timing marks on the crankshaft pulley are off or misaligned? I verified with the screw driver down the spark plug hole but there's such a huge range on the numbers where I can't feel the piston move any more. I can feel it start going back down about a quarter/half inch past the degree plate

[maxbraketorque]

Originally Posted by Vitzaa

I'm wondering if my timing marks on the crankshaft pulley are off or misaligned? I verified with the screw driver down the spark plug hole but there's such a huge range on the numbers where I can't feel the piston move any more. I can feel it start going back down about a quarter/half inch past the degree plate

I was wondering how you were going to do the alignment. From what I saw, the late model XJs have a tiny slot on the harmonic damper and then a single line on the block. Is that what you have on your XJ?

Did you disconnect the battery after your initial alignment?

The videos I watched seem to suggest that there is a pretty wide range of camshaft position sensor body angles where the ECU can successfully sync the camshaft position sensor signal.

Is there a chance that your camshaft position sensor is damaged, or maybe there is something off with your crankshaft position sensor replacement?

[RCP Phx]

Originally Posted by maxbraketorque

I was wondering how you were going to do the alignment. From what I saw, the late model XJs have a tiny slot on the harmonic damper and then a single line on the block. Is that what you have on your XJ?Did you disconnect the battery after your initial alignment?
The videos I watched seem to suggest that there is a pretty wide range of camshaft position sensor body angles where the ECU can successfully sync the camshaft position sensor signal.
Is there a chance that your camshaft position sensor is damaged, or maybe there is something off with your crankshaft position sensor replacement?

There's at least 2 reasons for that:
1 - the sensor has a tolerance range of at least + or - 3* with no affect on anything
2 - the assembled body can be rotated to any position as long as the pick-up was timed correctly

[Vitzaa]

It's just so weird this isn't working.

I do have a tiny slot on the harmonic balancer but the plate with degrees have increments of 8° 6° 4° 2° 0. With notches in between the numbers. I'm guessing the timing chain cover was replaced at one point. The timing chain and sprockets were replaced by a shop before we started our road trip journey and have 4k miles on them...

The synchronizer came with a cam position sensor. I also replaced the sensor today with a new spare one I had. Both sensors exhibited the same symptoms. The sensor is pointing towards the firewall and is parallel with the engine. With the engine in TDC, the open cup inside the synchronizer faces the firewall and is slightly angled towards driver side.

I did disconnect ground on the battery after the synchronizer install.

I'll shoot a video of it tomorrow

My camshaft sensor connector (wiring harness side) does have some exposed/l wiring on the base and the plastic insulation is brittle. I ordered a replacement connector and going to pick it up tomorrow so that I can solder it in.

I'm just totally stumped. I've got the factory service manual and have followed the steps to a t. I'm guessing something is fudged with the degree marks on the timing chain cover? Spoke to a buddy today and said all the timing chain covers from '84-'01 are identical so the numbers should correspond...

I'm totally stumped and have no idea what's happening here

[RCP Phx]

Originally Posted by Vitzaa

I do have a tiny slot on the harmonic balancer but the plate with degrees have increments of 8° 6° 4° 2° 0. With notches in between the numbers.
I'm guessing something is fudged with the degree marks on the timing chain cover? Spoke to a buddy today and said all the timing chain covers from '84-'01 are identical so the numbers should correspond...

The 2000-01 has factory marks! The harmonic balancer spinning is a real possibility though.

[Vitzaa]

Originally Posted by RCP Phx

The 2000-01 has factory marks! The harmonic balancer spinning is a real possibility though.

I'm not following the timing marks comment. Are you saying the '00/'01 timing marks on the timing chain cover would have the 0 at a different spot than pre '00?

Have you or anyone ever heard of the harmonic balancer mark getting displaced? Ive never fumbled with one so I'm not sure how it's assembled (pressed vs welded)

[Anak]

The potential problem with the balancer is that the outer ring will move relative to the center. The two are held in relative position by a ring of rubber in the center. Over time the rubber degrades and the outer ring could slip.

By this time, most XJs probably need to have their balancer replaced. Note that this is not something you want to hammer into place. Balancer removal tools and installation tools may be "rented" from some parts stores.

[75SV1]

Originally Posted by Vitzaa

I'm not following the timing marks comment. Are you saying the '00/'01 timing marks on the timing chain cover would have the 0 at a different spot than pre '00?

Have you or anyone ever heard of the harmonic balancer mark getting displaced? Ive never fumbled with one so I'm not sure how it's assembled (pressed vs welded)

Yes, I've had one fail or slip on me. I replace them if I buy a used XJ.

[maxbraketorque]

Originally Posted by maxbraketorque

..., or maybe there is something off with your crankshaft position sensor replacement?

Just making sure that you saw my previous comment about CPS.

[Vitzaa]

Verified TDC manually with a screw driver... The balancer is half a degree off, which isn't much, and the synchronizer holes still align.

I did find the potential culprit. When I took out the #1 plug I noticed two hairline cracks on the ceramic insulator... Started picking at it and half the insulator fell off. Gonna get a taxi to town and pick up a set of plugs. If that's the culprit, talk about a simple overlook. Fingers crossed.

[Vitzaa]

Originally Posted by maxbraketorque

Just making sure that you saw my previous comment about CPS.

Yes, it's a Mopar unit so I doubt it's defective, it's also a straightforward install with having just the two holes on the mount and not needing alignment... If the new plugs don't fix it I'll dig into the crank sensor and wiring.

[Vitzaa]

Originally Posted by maxbraketorque

Just making sure that you saw my previous comment about CPS.

Also, regarding the computerized drb tool calibration, I don't have access to one and every shop is booked out and can't see me for weeks. Tried mobile mechanics and no dice either

[Vitzaa]

Everything is resolved and jeep works like a top! Idles much better with the fresh ngk plugs... I'm so relieved. Phew!

You guys recommend to get the cam synchronizer tuned with the DRB tool? At least I can drive to a dealer somewhere to get it done

Thanks so much for all the help and support, y'all rock!!

[RCP Phx]

No, the fsm considers the toothpick method as accurate. I've checked before and you would not like what they charge just to plug-in the drb. Btw a good scanner can read the sync info.