Wire off!

[Pogo]

Can anyone tell me what the sensor / thingy is at the back of the engine on my GTI 1.9 8v?
Only the wire isn't connected to anything and seems to have broken off, but I can't find where from.
Everything seems to be working normally
It the thingy with the wire coming up towrds the camera

[BX Bandit]

Looks like either tdc sensor or crank angle sensor. Position wise I'd guess as crank angle sensor but if it is broken, then you'd have engine running issues. That's my best guess and as I'm unfamiliar with the 8v I'd have to leave it there!

[Pogo]

Thanks, I was thinking crank sensor,but would the engine run with this wire broken off though?

[RobC]

Do you mean the green wire or the thick black one? If it's the green wire then it could be either the oil temperature sensor lead or one of the two oil level sensor leads. There are also often one or two other thin green wires in the BX loom that float around the engine bay not connected to anything, in my experience, presumably there due to different equipment fitted on different models...

However if it's the thick black wire then yes I'd go with TDC / CAS as per Bandit! Funny how the engine runs with it disconnected though...

[Pogo]

According to honest John, the engine will run with the crank sensor disconnected (in a 205 Gti), and is only used for timing?, it seems like it was broken a while ago by the state of it.

http://www.eurocarparts.com/engine-management-sensor" onclick="window.open(this.href);return false;

It looks very similar, but I'm still not sure.

[mat_fenwick]

I'm not too familiar with the dates they changed over, but the crank sensor was only used on the Motronic engine management system, and I think a 1990 is likely to be Jetronic. If my recollections are correct then it's possible the gearbox has been swapped at some point with one from a later model (the sensor is at the top of the bellhousing) and it just left in place, dangling.

[JayW]

Can you see where the other end goes?

My 8v had 2 earths to the gearbox, one thick and one thinner.

[Pogo]

Car is JETRONIC. Can't find the other end!
Should it connect under the coil somewhere?

[Pogo]

http://www.ebay.co.uk/itm/Crank-Positio ... 2c7342e05c" onclick="window.open(this.href);return false;

According to this listing, the part is for a GTI of this year (Mine is 1990).
Confused. I am contacting the last owner to see if he can shed any light.

Looking at my picture again, it is fitted to the end of the bellhousing isn't it?

[JayW]

The crank sensor is fitted directly on the top of the bellhousing close to the block (so it aligns with the flywheel).

The loose wire in your pic is not for the crank sensor, it has the wrong termination and i'd still go0 for earth...

[Pogo]

No, not an earth as I've taken off the sensor (just pulled out), so can't be an earth

[mat_fenwick]

The eBay link you've posted is for the primitive 'diagnostic socket' fitted to some XU and TU engines. It's not really a diagnostic socket at all, but referred to as such in some manuals - all it allows is for you to plug in something to tell you the revs. If the connector you have matches the one in the link I'm certain that's what you have, but I had forgotten about its presence until now!. The connector is usually mounted next to the coil on the engines I've seen, and not actually connected to anything.

Certainly the Jetronic system doesn't have the input for a crank signal.

[JayW]

Sorry, i've just looked yet again at the photo, i thought i was looking at a spade-ended eylet, but now i'm not sure what you're all seeing!

[mat_fenwick]

It does look like the earth eyelet, with the reflection from it, but the OP is talking about a sensor. And the writing on it suggests moulded plastic. Try squinting a bit and you might see it totally differently!

[JayW]

Ahhhhhh! All becomes clear (looking on the big screen instead of my pocket PC)!

Yeah, as previously mentioned, it's the crank sensor which isn't supposed to be on a '90.
Look at your ECU under the drivers seat and it'll say "Jetronic" instead of "Motronic". Someones changed your gearbox and left the sensor in situ.