Jag help needed

[Liteace]

Hi All need a little advice. I have here a Jag 89-90 XJ40 4.0L, the car has been sitting for a year or so, It didn?t have a spark so Ive changed the ignition module and now I get a very weak spark every now and again, Ive checked the coil, the resistance is a little out from what it says in AD but it does work as it?s the same as what?s used on a early Fords and ive tried it on an old Sierra we have here, according to AD I should be seeing 1.1 volts AC when cranking from the CKP, Ive removed the plugs so it cranks faster, if I unplug the CKP from the ECM Im only getting about 350mv. I have also checked the output of the ECM, on pin 4 (blue plug) Im seeing 5v with ignition on, that?s correct, Ive scoped pin 1 (ECM to Ignition module)(blue plug) and Im only seeing a waveform every now and again, like Im seeing a spark every now and again, question is does anyone know what the resistance should be on the CKP with it off the car. The problem is we don?t have many Jags over here and the only place I can get parts from is main dealer or UK I don?t want to order from UK and find out that its not that, so if anyone could help me out here I?d really appreciate it

Thanks
Steve

[r6eck]

350mv not enough from crank sensor ,
crank sensors were always a bit poor on jags,
check airgap failing that new sensor required

resistance from memory between aprox 800 and 1200 ohms(same as most ac pickups)

[cristec]

Have you checked the voltage on the ignition coil, should have battery voltage on ignition feed side.
If it is low this is usually caused by dry joints in the drivers side kick panel fuse box, can be dismantled and re-soldered.

HTH

[Liteace]

Have you checked the voltage on the ignition coil, should have battery voltage on ignition feed side.
If it is low this is usually caused by dry joints in the drivers side kick panel fuse box, can be dismantled and re-soldered.

HTH

Thanks, Ive done that, theres a good 12v feed there, I also put a load on it to make sure it stays constant and it does so it looks like it?s the crank sensor

[Liteace]

Ive checked the crank sensors and its got open circuit, according to Lucas tech sheet it should have 1350 ohms so it looks like thats the problem.
Thanks all for your help