Non starter

[HaylingJag]

Men of infinite knowledge'

I have a 1990 XjR 4.0 which since it's winter lay up refuses to start.i have renewed the coil, dizzy cap, rotor arm and had the immobiliser disconnected and still nothing. car turns over sweetly just no spark and apparently no no pulse to the injectors. I wave taken it to a trusted garage to diagnose but it has him stumped too. Next thing to try is the cam position sensor, could I be right in assuming this could be the cause? The other thing to consider is potential damage to the ecu from jump starting it, any thoughts please,

Cheers
Darren

[Tame Technician]

Crank sensor is usuall if you loose spark and injector pulse together.

Think we used to put a heel board fuse box on xj40's and x300's also for this, but was a long time ago memory is poor.

[Jaguar steve]

Yes it could be crank position sensor.

A indication - not always a guaranteed diagnosis - is when turning the engine over the rev counter should flicker slightly - if not then I'd make sure the sensor connections are clean and sound and if they are replace the sensor as these can randomly fail.

[HaylingJag]

Thank you Men,

this will be the next step

D

[Jim AK]

Same issue with my 96 X300 3.2 Sovereign.Been laid up since mid January.

Should I be looking at same things?

[Jaguar steve]

Jim AK said:

Same issue with my 96 X300 3.2 Sovereign.Been laid up since mid January.

Should I be looking at same things?

Depends on the exact symptoms but yes, crank position sensor is a likely candidate for sudden failure to start. Do the usual free stuff first - check fuses, plugs, under bonnet connections and see if the rev counter flickers when you turn the engine over.

If the engine won't even turn over but know the battery is good then you may have a immobiliser or starter/wiring fault

[HaylingJag]

New CPS dispatched overnight from David Manners, £114 gamble has paid off, all up and running like a dream

Still waiting for Harwoods, Chichester to come back to me with a price for a CPS their loss!

thanks fellas, for the input much appreciated.

[Jim AK]

Thanks for info JS. No movement in counter whilst cranking, only 1 small movement on turning ignition to 2nd position before cranking. Sounds like il be getting my hands dirty Saturday!!!

Good result for you HJ. You will be enjoying your Jag before me.

[Tame Technician]

Perhaps I should have added.....(I dont feel so guilty now its fixed) ...you can test them, so no need to gamble.

There should be about 1000ohms resistance across the two pins.

If its open circuit its TF'ed

Test the old one now its off see what it says compaired to the new one, be handy for anyone else.