Does The 1.6i Have Ecu Temp Sensor?

[Ricardo 0]

Thought my idle speed may be down to needing a new ECU Temp sensor but read somewhere the LE2 Jetronic multipoint fuel injection system doesn't have one

Is this right?

Cheers

[EdCherry 34 1 Cars]

No, it does have one. Blue plug under the dizzy cap.

[Ricardo 0]

OK cheers for that. Good old Haynes manual!!!

 

I'll check it out now and maybe get a new one anyway.

Thanks again.

[Ricardo 0]

Is there an ECU temp sensor in the AFM (1.6)?

[GLPoomobile 958]

Part of the AFM is an air temp sensor, so yes to your question above. The AFM works by airflow, so the flap opens against spring tension and move an arm across a carbon track, and it also works by air temp, monitored by the above mentioned sensor. You'll see this sensor in front of the flap if you look in at the incoming side. This is not a replaceable part.

 

Don't confuse it with the ECU temp sensor. This is something that monitors the coolant temp so the ECU knows what the engine temperature is. So if you start it on a freezing cold morning, the ECU knows the engine is stone cold and will inject extra fuel. This combined with the extra air flow provided by the SAD will up the revs. An electronic choke in other words.

[Ricardo 0]

Cheers that has cleared my confusion

Doesn't help me sort the cold tickover tho unfortunately!

SAD works and there is voltage to it. No leaks.

 

Could the ECU temp sensor (water) cause low cold tickover if faulty but not effect running when hot?

Cheers again I'll just replace it anyway I think.

Richard

[GLPoomobile 958]

They're funny buggers those sensors. They can be totally shot and cause constant over fuelling, or they can have intermitant faults causing mucho confusion, then you can have a sensor that works but broken wiring in the loom or terminals that have pushed back inside the plug, again causing intermitant faults.

 

There are resistance tests you can do on them, where you check the resistance across the pins when the sensor is placed in water at varying temps. But that can end up being a red herring if the sensor is intermittantly faulty.

 

For what they cost and ease of fitting, I would usually say they are worth swapping if ever in doubt.

 

You haven't gone in to detail about your idle problem though, so I can;t offer any advice, except to say that just about every 205 GTI owner will have experienced idle problems, and it's usually a combination of many things, but not usually the ECU temp sensor.

[Ricardo 0]

Well I've ordered a sensor for wot it's worth (£12 from GSF inc vat+pp!)

Had the SAD off and adjusted it with the small stud, and had the 'pie hole' when cold and almost totally closed on the house radiator. Voltage is OK at the SAD terminals. Cleaned breather and air pipes. Haven't checked the TPS 'click' yet.

I started looking into this in august and you gave me some sound advise, I shan't touch the AFM spring!

Could the air temp sensor in the AFM effect idle? would cleaning it with carb cleaner help?

The difference isn't too bad cold to hot, about 900 - 1100. Doesn't usually get too low as to cut out but dips to about 700 then back to 900 unless just been thrashed and then its 1100-1200 untill throttle blipped.

Next I will remove and clean the throttle body even tho I've cleaned mixture screw and afm side of butterfly.

Thanks for the input.