Hi all, I've done a search but not really found out what should happen when you unplug the blue temp sensor? I just unplugged mine with the engine running after my drive home and left it to idle, seem's the engine felt a bit smoother and I'm more than sure for the 30secs or so it idled normally, when I plugged it back in it started to have a slight mis-fire again!

So my question is what should happen when I unplug the sensor while the cars running?

Rich.

Hi all, I've done a search but not really found out what should happen when you unplug the blue temp sensor? I just unplugged mine with the engine running after my drive home and left it to idle, seem's the engine felt a bit smoother and I'm more than sure for the 30secs or so it idled normally, when I plugged it back in it started to have a slight mis-fire again!

So my question is what should happen when I unplug the sensor while the cars running?

Rich.

Rich mate,

When you unplug the sensor your revs should come up at idle by about 200 revs as it increases the fueling. If it runs abit rough with it plugged in then you need to check your dizzy timing. Unplug the blue temp, give it two revs about 2k (resets the ecu) then do the dizzy timing with a gun. Plug the sensor back in and it should run sweet as a run. Unless your mechanical timing is out.

Hmm! I've no idea how to check the dizzy timing etc but I guess I'll have a look in to getting it done - Does the fact it runs poo with the sensor plugged in (mainly when electrics are on or when at idle/pulling off) mean that the sensor is infact fine? as a lot of people have told me it's likely to be the blue sensor!

Strange thing is it can run perfect for ages and then suddenly start spazzing out and then the revs drop a bit then raise again etc night time it's more likely to happen/stall due to the electricals that are on!

Thanks btw matey

Rich.

Edited 29 October, 201015 yr by lingl9z

This is a good topic for Blue Sensor problems and tuning

http://www.clubpolo.co.uk/forum/index.php?showtopic=109802

Thanks for that link buddy will give this ago at the weekend regard the idle etc as when I changed it I never knew about removing that blue temp sensor to set it etc!

just a quick one - Wheres the plug for the lamda sensor isit located under the car by the sensor or is it in the engine bay or something?

Rich.

The lamda sensor plug is usually on the inlet manifold plug mounting bracket iirc

The lamda sensor plug is usually on the inlet manifold plug mounting bracket iirc

Cheers buddy any idea to which one it is? :)

The lamda sensor plug is usually on the inlet manifold plug mounting bracket iirc

Cheers buddy any idea to which one it is? :)

Hopefully going to a breakers yard to find some bits, anyone advise me on what to get that could be a relation to this problem so I can try and eliminate problems!

Blue temp Sensor?

AFM? (I assume just the bit that the wire plugs in too?)

Lambda?

TPS?

I did unplug the blue temp sensor which made it run better (only while idling) but was told it'd put it in service mode - I assume unplugging any sensor will make the car run a failsafe map and should in theory run a lot better but then I guess I wouldnt know what the actual problem is! =(

Any other advice for when I go to scrappy.

Thanks again

Rich.

The lamda sensor plug is usually on the inlet manifold plug mounting bracket iirc

The lambda sensor is a sensor that measures fuel/air ratio after combustion.... Meaning that its found in your exhaust. Just before the catalytic converter to be exact.

Also ,if unplugging your blue temp sensor makes your engine resume normal running condition , It is obviously faulty and needs replacing. A few quid from GSF! ,

By the way, The blue temp sensor is there to relay coolant temperature information back to the ECU. If the coolant temp is cold , The ECU adds more fuel to the mixture up until normal running temperature is reached.

and if your blue temp sensor is faulty, It will be chucking in fuel when its not needed. Meaning that MPG and running conditions will suffer massively.

Max

Edited 3 November, 201015 yr by MaxMax

The lamda sensor plug is usually on the inlet manifold plug mounting bracket iirc

The lambda sensor is a sensor that measures fuel/air ratio after combustion.... Meaning that its found in your exhaust. Just before the catalytic converter to be exact.

Also ,if unplugging your blue temp sensor makes your engine resume normal running condition , It is obviously faulty and needs replacing. A few quid from GSF! ,

By the way, The blue temp sensor is there to relay coolant temperature information back to the ECU. If the coolant temp is cold , The ECU adds more fuel to the mixture up until normal running temperature is reached.

and if your blue temp sensor is faulty, It will be chucking in fuel when its not needed. Meaning that MPG and running conditions will suffer massively.

Max

Thanks for that buddy although my symptons seem slightly different to threads I've read as the ones that suffered with a blue sensor that's failed had poor running until warm, mines usually fine untill warm (not that I can see due to the temp gauge not reading!)

can anyone post me a pic of the TPS/Lambda sensor plug location please? would be really helpful :p

Rich.

Well to be honest , it makes more sense that engines with a faulty blue temp sensor would suffer at normal operating temperature, But be OK when warming up.

It will be adding in too much fuel when warming up, Which will almost help in this respect. But when it starts to reach operating temp (90 degree's) , It will still be adding in too much fuel still, Meaning that you will have a fuel rich mixture which reflects the bad running issues you have.

If your temp gauge isn't working, It will be more than likely your black temp sensor, Its this sensors job to work your gauge.

Change them both ASAP :-D

can anyone post me a pic of the TPS/Lambda sensor plug location please? would be really helpful :p

Rich.

Its just before your catalytic converter, Which is just after your downpipe in your exhaust, Have a look under the car, You will see a it straight away as its got wire going to it.

sorry to hijack but i have a similar problem and am trying to narrow down the prob..my car's current operating temp is 70 degrees..should it not be 90? its running fine but mpg are horrendous.. have to buy a lambda probe and a blue temp sensor so.. any other things i should change?

Air filter?

What car is it?

Air filter?

What car is it?

sorry. its a polo gt. but my air filter has only done a few hundred miles,its a jetex panel filter. dunno if this helps?

Hmm okay will give them all a check, may try a second hand one from scrappy as they'll be pence (could still be faulty but if it works I can go ahead and get a new one!) where's the actual plug for the lambda on the inlet? that I could disconnect? any pictures?

Rich.

Thanks again btw!

The actual probe is no where near the inlet , Its in the exhaust.

The connector may be somewhere near your inlet manifold , Have a look?

Have you had a look at the wires coming from the probe?

Not had a chance yet tbh with you but I have a rough idea what the lambda looks like from doing it on the old 306 GTI-6 ! just wondering where the connector was to swap it out etc! Thanjs fir the help max!

Yeah you will have to undo the connector to disconnect it obviously.

just follow the wire and you'll find it.

Cheers buddy hopefully get a few bits tomorrow if I can find any - Any other cars that the bits will fit from? The 8v Gti AFM a straight fit? (Mk2 golf)

The connector is clipped to a bracket on the inlet manifold as has been said above. Juust follow the wires from hhe probe in theexhaudt under the engine. One that's been sat in a scrapyards isn't likely to be much good though.

Cheers guys, there a way of cleaning them as a temp fix (just to see if it is that) as I don't want to spend out 60 odd quid if it's not at fault as I'm a bit tight on money now xmas is here!

Nah once it's gone it's gone, but try a scrapyards one and see if it's any different anyway