Good day all. New to Jag and the Jaguarforum so bear with me.
I purchased a 95 XJR last fall, ran great with no issues.
Took it out of storage yesterday and it had a miss I blamed on last years fuel in the tank. Put in a can of seafoam and topped it up with premium. changed the supercharger belt as it was coming apart.ran like crap all day, sometimes all 6 cylinders(fun!!) sometimes 3 and then 2. shut it off to have supper. went out later and it wouldn't start. we took it to a buddies shop, OBDII would not connect, and it has no spark and no signal to the fuel injectors.
Point me in a direction please. Thank you much.

 

I *think* a dead crankshaft sensor would account for no spark and no injector pulse. Wait for others to chime in, though

Cheers
DD

 

May also be a relay.

 

Crank sensor is what we came up with to. we checked it with a graphic scope and it appeared to be working, consistent highs and lows.

Resistance on the crank sensor should be about 1.35 ohms(cant remember the range)?

Is there an ignition control module on these cars? Or is it all in the ECU in the trunk?

Also the relay would be on the Passenger Front fender (LHD)?

 

Crank angle sensor = spark.

Cam angle sensor (that wizzy thing where a distibutor used to live) = sequential injection pulse.

Relay = RH engine bay fuse box, the Blue one = Ignition relay.

 

Seems odd to lose both the fuel and ignition at the same time.

 

Agreed.

My system of checks would be to probe the red (i think) wire going TO the crank angle sensor. It should have battery voltage with the ign ON. Anyway, one of the 2 wires should have battery volts, and that is supplied from that relay, so if you got volts the relay is more than likely OK.

Get a mate, put him in the boot (trunk), turn on the ign, and he should hear the fuel pump whirr, if you got whirr, pump is working, step 1. No got whirr, maybe pump has died, they do that, or more than likely the FP relay is having a moment??. Got whirr, then go the the fuel rail fitting at the rear of that rail, and carefully "crack" that 2 nut connection, as see if you actually got fuel supply, step 2. This will confirm fuel is getting to the rail/injectors, as the fuel hose from the pump (inside the tank) has been known to blow off, so the pump whirrs, but fuel just sprays around inside the tank, good job, NOT.

Then I would remove a coil, plug a spare spark plug in the end, and earth the spark plug on something, and crank the engine, and see if spark is happening. That will deem the crank angle sensor, good or bad, and it is the most common culprit. Mine went legs up in the driveway, as I changed from work clothes to going out clothes, drove in fine, not a thing 10 minutes later, swapped the sensor with mates car, good as.

I would also unplug and replug the connections on the cam angle sensor, the airflow meter etc, just because.

 

Thank you to all who Chimed in. I must admit I am the fool.
The security system had taken a hold of the car. A couple turns of the key in the drivers door and away it went.

Now it looks like I will be chasing the spark issue. The tach is reading about 3500-4000 rpm at idle. From what i have been reading I need to check my coil packs.

is there a resistance that they should measure?

 

Hey, don't be harsh on yourself

 

The only spec I've ever found is .75 ohm primary resistance....that is, the resistance measured between the two connection pins

Cheers
DD