Hi everyone, for the first time in 15 years of continuous Jaguar ownership I have a no start situation at 98,898 miles.
Monday evening my 1990 Majestic crapped out. I had the car put on the rescue truck and delivered to my driveway.
What I found, what I did;
1. No fuel in the fuel rail. I replaced the the fuel pump with a Denso 951-9002 (bought for replacement a little later along with filter).
2. Replaced the crankshaft position sensor with a new one I had, (spliced in the old plug)
3. In order to "easily" replace the CPS I removed the SLS valve block, pump and plumbing.
4. Had spark.

Barely started, idled decently, wouldn't accelerate, shut it down, wouldn't restart. DTCs 29, 44.
Yesterday removed neg. terminal from battery, started after a few turns, fast idle (800 RPM), wouldn't accelerate and died when I pressed the accelerator.
DTC 14 - connector was loose re-attached, cleared DTC and no restart.

Where to look; any ideas? The car ran fine before all of this trouble.
I have the workshop DVD and will start at the beginning of diagnostics, to be sure any possibilities are greatly appreciated.

Thanks,
Roger

 

There was a recent thread where a similar situation occurred and I believe after much consternation the fault led back to the spliced plug CPS which IIRC was the incorrect part?

here's the thread, several red herrings along the way but a good result (long but well worth a read)

https://www.jaguarforums.com/forum/x...500rpm-185132/

Larry

 

Hi Roger,

So sorry to hear about your no start. In addition to Larry's great question about your CPS splicing, remember that a basic test of the CPS is to watch the tachometer while cranking the engine. It should read around 200rpm. If it registers 0rpm, suspect the new CPS or the spliced wires.

I'm curious to know if you carried out any diagnostics on the fuel pump electrical circuit prior to replacing the pump? It's easy enough to swap another relay for the fuel pump relay and to test for the correct voltages at the fuel pump relay socket.

If you don't have the electrical guide, you can download it here:

Jaguar XJ40 Electrical Guide 1990

Cheers,

Don

 

My Majestic needed a tuneup!

I changed the spark plugs, coil, ignition control module and installed a new, correct CPS. I turned the key and it fired right up. The spark plugs had virtually no electrodes left and likely burned the coil out. I had all of the parts here in my parts drawer and the new CPS was delivered by noon.

The CPS sensor itself is a Lucas CS4 and is the same I've seen in six cylinder Jaguar applications. The new CPS I removed will have proper plug/receptacle (on order from Corsa Technic) installed removing the splice and reducing the overall length to 17 inches.

For years I've replaced all items prone to failure, on my vehicles, at the 100,000 mile mark. This routine has saved me substantial heartburn. My Majestic crossed the 99,000 mile mark during the test drive yesterday.

Before the holidays I'll finish up my 100,000 mile maintenance routine by replacing the starter motor and the remaining items on my list.

 

My no start was caused by a burned out secondary circuit in the coil. Spec is 6 to 6.5k ohms, my coil measured 7.3k ohms.