2000 Vanden Plas, 90k miles. Engine running great until the noise from the timing chains. Bought the parts but didn't buy the special tool to lock the cams. Had a bear of a time but finished. Engine started but wouldn't run below 1000 rpm. Realized we screwed up. Tried looking for vacuum leaks, etc. No luck! Somebody suggested resetting the computer by disconnecting a terminal on the battery and frankly, I don't remember what I did. From then on, it ran very rough and I got the diminished performance message. So we opened it up and found out we were off by one tooth. The cams are still in sync (flats up and equal but not at TDC of left front cylinder). Reset the chains and rotated several rotations to verify. Now it won't start. Begins to start but cuts out while cranking. The more we do, the worse it gets. Can only work on it during weekends but my frustration is starting to wear me out. Is the computer not allowing the engine to start because of all the new wrong data it has gotten from our repair efforts? Any ideas? Thanks for reading. Oteymus

 

Maybe bore wash

 

Please move this to the X308 section.

bob

 

Hi Oteymus,

I have moved your thread from the forum for the X350 to the forum for the X308, which is the Jaguar factory project code for your 2000 VDP.

One thought that occurs to me is that your Crankshaft Position Sensor (CKPS) may not be reconnected. A known issue is that when connecting the two halves of the electrical connector one or more of the pins may back out of the connector, preventing a proper connection. Since the Engine Control Module (ECM or computer) relies on the Camshaft Position Sensor (CMP) to establish initial timing within less than one engine revolution, then relies on the CKPS signal for engine timing from that point on, it seems possible the engine might seem to start while cranking based on the CMP signal, but without a good CKPS signal the ECM can't maintain timing and shuts off the ignition by default.

Just a theory, but worth ruling out.

Cheers,

Don

 

1. you've been VERY lucky running offset from TDC and getting away with it
2. disconnecting the battery terminal (a.k.a 'hard reset') only loses learned adaptations such as fuel trims - it doesn't lose the ECU programming
3. as JagV8 wrote in post #2, after all the cranking bore wash is likely
4. Don B puts forward a beautiful theory for CKPS malfunction

Dry the plugs, prime the cylinder bores, check all electrical connections again. Also check for air leaks at MAF sensor and Throttle Body.

Graham

 

And......

Always disconnect the battery whenever you are working on the Jag, even if you are only replacing a light bulb, disconnect it.

Leaving it connected for an oil change is the only work I would risk doing with the electrical system live.

The computers in our cars (yes, there is more than one!) are very sensitive and if you get some voltage where it shouldn't go you could have big trouble.
Vector