GOLFII is down.

[Spyda]

Have you got any wires cut somewhere ? Follow the loom back to the back of the firewall.

The colors would be Brown/White and Brown/Green for the Blue temp sender that goes to the ECU.

Not sure what long term effect it would have on the motor. Just get it fixed.

The wires come out from the ECU main plug at pins 6(brown/white) & 10(brown/green)

Thanks mate, ill have a look when it stop raining. If i cant get it worked out ill take it to volkswerks or some place.

[Spyda]

Looked at the wires coming from the plug and they are brown with green and brown with white. So that means they are for the blue sensor. I pluged it in and everything was fine till the earth cable for the ignition coil came loose (it keeps coming loose while driving).

When this happens does something reset? Because the car wont run properly untill i diconect the blue sensor cable. Then when i plug it in later it is fine.

I dont get it.

And now what about the other white sensor?

[aussieg60]

How is your water temp gauge working then ?
It should be connected to your other sensor (white for you, mines black)
Wire colors should be Red/Yellow and Brown.

[Spyda]

How is your water temp gauge working then ?
It should be connected to your other sensor (white for you, mines black)
Wire colors should be Red/Yellow and Brown.

I have no idea. But it does work.

When i plug in the blue sensor the car doesnt work properly, the idel drops to 750 and if you step on the throttle it coughs and strugles and then turns off. If i unplug it the car will go but no matter how much throttle you give it below 3k rpm it feels like it has lost half its power then comes back like a turbo after 3k rpm.
Funny thing is that it didnt work when i got the car, then it did work after i got the shoks and stuff fited and then when i washed the car it didnt work.

I cant find the other sensor wires or plug anywhere.

Any idea on how to fix the blue sensor problem?

*EDIT*
Ok, had a good look. Found a yellow wire with red stripe and brown wire they are pluged in under, as shown below. Another thing i have to corect is that the wires that are atached to the top of the oil filter dont run in to the same sleeve as the brown/White and Brown/Green for the Blue temp sender. They are two different sleaves cable tied together. One sleave contains the brown/White and Brown/Green for the Blue temp sender and the other contains the wires that are attached to the top of the oil filter and the yellow/red and brown wire.

This is where the yellow/red and brown wire are pluged in to. Any ideas why it is here? Is this normal? how do i fix the blue temp sender problem? are these sensors related?

[aussieg60]

That picture makes a bit more sense now.

What you have is the new OEM flange where the bottom is usually blanked off and the top 2 are usually used for the temp senders on a MK2. Someones, stuck the temp sensor down the bottom, hence you got an extra sender on top (white). I suppose you got a spare or bakup. The bottom connector is your temp sender for your gauge by looking at the color of the wires and that seems to work ok as you say.

Did the car run better with it plugged in the white sensor ? Maybe the blue sensor is faulty ?

[Spyda]

That picture makes a bit more sense now.

What you have is the new OEM flange where the bottom is usually blanked off and the top 2 are usually used for the temp senders on a MK2. Someones, stuck the temp sensor down the bottom, hence you got an extra sender on top (white). I suppose you got a spare or bakup. The bottom connector is your temp sender for your gauge by looking at the color of the wires and that seems to work ok as you say.

Did the car run better with it plugged in the white sensor ? Maybe the blue sensor is faulty ?

The white sensor was replaced 3 times and it didnt make a difference when pluging it in to the white one instead of the blue one.

ECU fault?

BTW Thanks for helping me out mate.

[GOLFBALLS]

Your car is digifant i'm guessing.
Mine is/was k-jet but i think a similar issue happened to mine. The blue plug on my car was at the end of the intake manifold and connected to a kind of 'fifth' injector to deliver more fuel for cold starting. Maybe vw use the blue to symbolise temperature? I had bad running when cold but it got worse when engine was warm! Turned out the engine temp sensor was faulty and consequently giving a "cold engine" reading to the metering head which in turn told the 5th injector to kick in, thus giving too rich a mixture causing bad running especially at idle.
I disconnected the blue plug to disable the cold start injector and it was a little rough when cold but obviously improved once it was warm because the mixture wasnt so rich.
Perhaps the water got in somewhere and shorted something with your temp sensor plug and now its giving wrong 'instructions' to the cold start mixture???
Just a thought...wade

[Spyda]

NEWS,
when i plug in the blue sensor in the moring (car 100% cold) the car runs perfect, like normal. When i parked at the train station, turned off the car, tryed to turn it back on to fix parking the problem was back. I left the car in the sun, so it wasnt full warm when i came back from the cbd but was warm and it would start fine but as soon as u start to drive the problem would come back.

The car runs fine when it goes from cold to warm but as soon as you turn it off and try to turn it back on while its warm the problem is there and i have to unplug the blue sensor so i can drive the car.

What do you guys rekon?

[Spyda]

Bump.

Any answers?

[GOLFBALLS]

yep, sounds like what i said.
Engine is getting too much fuel when warm. The blue plug is probably the thing giving the extra fuel.
Its gotta be something to do with the Digifant cold start valve which is prone to gremlins.
It thinks the engine is always cold so it feeds heaps of fuel like a choke, which is fine when engine is cold, but no good for a warm engine as it gives a really rich fuel mixture basically flooding the engine.
I'd say the blue plug/sensor is either the cold injector, or the thing that tells the cold injector to squirt more fuel in. This would explain why the car runs better when warm after you disconnect it (because you have stopped the flooding).
Maybe your engine temp sensor has died?
Wade

[aussieg60]

There is no "Digifant" cold start valve. The injectors are pulsed longer for extra fuel by the ecu.

[Spyda]

Ive ordered a new blue sensor, comes in on tuesday, $34 damn it

I hope it solves the problem.

[robiom]

Any joy ?

Hey Spyda,

Did you find the solution to your problem? Was it the Blue sensor that fixed it ?

I have a VERY similar sounding problem....after 2 days of finally buying my lovely MK2 at last

I just want to drive it now...

Thanks,

Rob

[benough]

The engine (dont worry thats not how the plug sits when the car is running)

Hey sorry to be a bit O/T but what that red air filter thing on your rocker cover?

Doesn't the stock thing connect via a hose to somewhere?

Thanks

[h100vw]

You can check any of those sensors with a multimeter on OHMS range. Hook to the sensor and watch the resistance change as the water gets hotter. I don't know the figures but the resistance should start higher and come down as it gets hot. NTC negative temperature coefficient.

I have been thinking about this one too. Again not having a book handy, I wonder if when the plug is disconnected, it also stops the ECU looking at the lambda probe. Which is in fact the real problem.....

Maybe Jimmy will chime in if he sees this thread.

Gavin