1995 XJ6 VDP 99K miles

Hi again,

Can someone tell me what are the various symptoms of Bad Crank Positioning Sensor so I can decide to replace mine or not?

My car starts beautifully and iddles superbly well.

Thanks you so much

Claude
Durham NC USA

 

Claude:
Then I guarantee you your CKPS fine! Now, it is a known failure item, so you might want to get one and put it in the trunk incase yours goes out, but as they say, if it ain't broke, dont fix it. There is no guarantee that the new one will work better than the old, and you might break the connector changing it.

A good sign your CKPS is bad is that if the car cranks, but the tach does not read 15-250 rpm, and it does not start, THERE'S YOUR SIGN!

 

Exactly as Ross said.

Mine was at 161k kms, and drove in the driveway, changed the clobber to take the wife out for a meal, NO start, BUGGA. All dressed up and no car to go in. Took her V12 and heard about reliability ALL damn night.

Luckily the guy next door was away, and I had his keys, so I nicked his crank sensor, and away it went. New one fitted to mine and his back in his car, all good.

I have that new one in mine, and a spare in the glovebox, coz if that sucker goes legs up, you are dead in the water.

For some reason 160k kms (100k miles) is the "magic number", and I do not have any explanation for it.

 

Hi again,

Thanks for your replies

If I read you correctly this CKPS is either "on" or "off" but no intermediate situation that could affect the engine running (meaning good start, good idle but a bit erratic engine betweee 2000 and 3000 RPM)

Thanks again

Claude

 

Yep.

That's the way I understand it. the thing is basically a counter, and the missing tooth on the wheel is what triggers what it does.

If you are getting odd running at specific revs, and it is fine above and below that rev mark, then I do doubt the sensor at the moment. If it is getting hissy at that rev mark and stays that way further up, then the sensor is high on my list, as is the fuel filter, and/or fuel pump.

The face of it is easily contaminated, so a wipe over will do no harm.

The connector, which hangs vertically, is another item that caused grief on mine recently, and I have since "sealed" that connector with RTV, and so far no issues, even after washing the area.