Crank Position Sensor

[paultv]

Was out having a thrash today, had a repeat of something I had a year ago, momentary power loss - half a second, like I turned off the ignition for a brief moment.

So I'm checking CPS wiring to the DME and happened to measure the sensor resistance which should be 540 ohms + or - 50 ohms, mine is a new one which measures 1.2K

Probably naff all to do with the issue, but handbook says "outside this tolerance, get a new sensor."

True or False? True....or False - I really wanna see those fingers!

Paul

[paultv]

So I reinstalled my old cps which measures correct impedance, and the car starts more quickly but the tickover is now 950, put the " new" one in and the tick is correct but less easy to start. So I reckon the old one is knackered and the new one is for a newer car, I read maybe an E36 has a 1.2kohm cps.

More testing to do,

Paul

[Speedtouch]

I would say if the new CPS measures twice the resistance of the original, you're probably better off sticking with the original, or get another proper new one.

I had a 1999 Fiat Seicento Sporting, which has the CPS mounted to the engine block; as the block heats up if you get stuck in traffic, the resistance of the CPS would rise to the point where the ECU couldn't read it and would shut the engine off - you would then have to park up and wait for 20 minutes before you could get going again.

It drove me mad, and I couldn't find a cure, despite fitting two new CPS and adding cooling ducting and reflective foil so I sold the POS.

[paultv]

I think I might bite the bullet and buy an original BMW item, the Meyle one which is cheap has the right resistance and looks the same but does not have the same part number... so could be another waste of money in the end.

My original BMW marked one has a damaged sleeve, and has AB marked on it - not sure who that is as a manufacturer?

Paul

[Speedtouch]

Can't you just use heat-shrink wrap to repair the sleeve?

[paultv]

Yes I could but the tickover runs too fast with this cps, so I guess it has some other problems.

Paul