Drinking fuel??

[h100vw]

Funny that because the blue temp sensor doesn't even work.

How do you know that??

[16v_kid]

How do you know that??

Because on the temp clock the needle doest move. The termoster works though, just not the temp reader.

[h100vw]

There are 2 water temp sensors in the top hose mate. The blue one is connected to the ECU so it knows when the engine has warmed up, the black one runs the temp gauge.

Swap the plugs over and see if the temp gauge moves then. This will prove the Blue sensor or the gauge/wiring.

[16v_kid]

I'll swap them over, but how will the ECU know when the engine is warm if sensor that will be connect to when swapped is faulty?

Regardless, I will need a new temp sensor.

[h100vw]

I'll swap them over, but how will the ECU know when the engine is warm if sensor that will be connect to when swapped is faulty?

Regardless, I will need a new temp sensor.

You have got it in one. If the car is pumping out black smoke it is clearly running rich. One reason could be that the ECU thinks the engine is cold. So runs a rich mixture.

You have stated the temp gauge doesn't work and think it's the sender? Swapping the plugs will do 2 things, prove if it is the wiring/gauge or the sender.

If the gauge starts working, then you can say the sender is the fault and get a new one. You will also know that the Blue sender is likely to be ok and that the black smoke is being caused by something else.

The idle screw is just to hold the tickover not to keep the engine running if you load it up, by selecting drive or having the AC on. There are idle-up signals and air-bypass solenoids for that (IIRC it will be idle up signals).

Once you have the senders sorted out, you need to check the output of the lambda probe with a multimeter. Start with a cold engine if possible, the probe will start out close to 0 Volts and as the engine warms the output will increase towards 1 Volt. Once right up to temp, it will cycle between .5 and 1 Volt. You can't see this with digital meter due to the sampling rate. You would see it hunt around but enough of a trend to say what it's doing is correct. If you get a solid voltage then there's something wrong with the probe or wiring.

[16v_kid]

I just swapped the sensors over. I let it run for a little while, rev it a little to, to get the temp up. The gauge didn't move!
It looks like both sensors are faulty. It also blows some smoke from the exhaust once warm up. Also, one of the wires that's meant to be connected to the lambda probe is ripped of.

[Golf Loon]

Listen to H100VW he speaks the truth. The blue sensor should have a blue connector and the black sensor a black connector.

I reckon that loose earth wire might be the earth for the lambda, connect it to a bolt on the rocker cover and see if that helps the smoke / economy.

I reckon I`d get 2 new sensors, check the lambda is working, or replace it anyway and check the timing, when car is warm with the blue temp wire disconnected.

Idle screw should have a good o ring on it too.

They are getting old these cars, but can still run nicely if setup well by a competent person. If you tinker with everything and replace stuff without diagnosis, you may never get it right.

Good Luck.

[h100vw]

That smoke looks like condensation to me. What does the oil temp get to on the MFA. That's a good guide to engine temp, the oil warms up slower so when it gets to 50 degrees, the water should be plenty warm enough.

That busted wire most likely won't be helping matters at all. You need to see if there's anything voltage coming out of the probe though. IIRC the black wire will be the signal to the ECU. You should get hold of the wiring diagram and make sure the probe wires are connected to the ECU.

Gavin

[ryana89]

I thought my car used alot of fuel, but judging by the soot over the back of the car, mine only seems a little thirsty
Btw yesterday I changed the BLACK temperature sender (thinking that it would probably do nothing and that my guage was faulty), and now my Temperature Guage works pefectly!
MK2's seem to warm up very very fast!

[16v_kid]

Thanks for helping out guys, appreciate it.

Will be fixing the wire tomorrow. I will need 2 new temp sensors to suit this engine and a new o-ring for the air bypass screw.

Can you help me source these parts Loon?

Thanks,
G.