Short story: driving at highway speed, car starts to skip and stall. Thinking there's an issue with CPS. Get home, check to find out the CPS bracket is loose. (!) Tighten it up and think all is right with the world.
Next time driving, engine light starts blinking then sets 2 codes. P0303 (misfire in cyl 3) and P1313 (bad one - possible cat damage - unspent fuel). Check coils, oil in the plug wells. Take care of the valve cover gaskets, clean the coil boots and contacts, change the plugs, make sure to switch the cyl 3 coil with the cyl 2 coil, clear the codes, and off for a test.
Now, sets P0304 (misfire in cyl 4) and P1314 (rear cat this time). Do nothing but clear the codes and take another test ride. Now back to P0303 and P1313.
Got to thinking (dangerous) it may be the CPS anyway - it's the original, so it may be iffy. I have another on order.
Question: Am I onto something, could an unstable signal from the CPS cause this weird chain of events? I'll update when the new CPS is installed.

 

6 or 12 cylinder lump?
The V12 has 2 CPS's
Breakdown can cause all sorts of weird problems.
As can the CTS.

 

AJ16 inline 6 - 96 xjs

 

Both my AJ16's dropped the CPS at 160000kms (100000miles), for no apparent reason.

BUT

The 3.2 still had female moments, and I eventually found the 2 pin loom connector, in that STUPID bracket on the front of the timing cover, had filled with oily crud over the years. Removed it and sealed the unused holes, cleaned both plug and socket, sprayed some lube and refitted, 5 years now, sweet as.

ALSO

If that CPS has rubbed on the crank star wheel, when it was loose, its probably past its replacement time, they dont like that treatment.

 

Yes, that's what I am thinking. I'll let you all know... thanks!

 

Yup, that deal with the CPS...
Replaced the old with the new today, set the proper air gap, and away we go. Issue solved. Thanks to all who engaged this post.

 

I didn't know there was a gap adjustment. What is the proper gap if I may ask, for the AJ16 engine?

 

Hi carsandplanes

Same question here, I had to fit a new CPS on 'Carmen' and from what I could see there was no way to adjust the Gap

 

Specified gap is .020 - .040. If an adjustment is necessary, you may need a file...

 

No files necessary. If you need more gap add a shim to the back side of the bracket. Easy to make shims out of nylon sheet, aluminum sheet, or hard gaskit paper. I doubt you would need less gap. The factory casts these items with great precision and on the tight side of spec.

My experience with these hall affect sensors has shown that they will will still work properly with a gap way out of spec on the open side, but they may exhibit signal loss as the RPM increases.