Fuel Temperature sensor - do you have one?

[mep12345]

Continuing to chase my high idle problem and think I may have narrowed it down to the AFM wiring but not sure where as the wiggle test with the star tester shows nothing but the engine running test comes back with AFM fault and the fault code follows the wiring when the two AFM connectors are swapped over (and also when a third one was used in place of the one that initially showed the fault). DVM reading seem to show an intermittent problem with the voltage supply and earth being fine but the air temperature sensor and the output wire sometimes steady at expected voltage and following revs respectively as they should but every now and again both seeming to go straight to 5V (i.e. breakthrough from the supply voltage of 5V).

Any ideas on this welcomed.

Also in also helping Mark (white S3) with his fuelling problem and some spares he mentioned the fuel temperature sensor next to the back pressure valve. Having looked up in the Haynes manual my car does not have one fitted (it has the threaded port but no sensor) and the wiring is there but clearly with no sensor is not connected to anything. The Haynes manual says to remove the sensor you need to depressurise the fuel rail so I would assume it would be open to the fuel rail, but clearly mine with a tapped hole has no fuel leakage so cannot be open to the fuel rail. Therefore my question is did they all have fuel temp sensors fitted and has mine been removed at some time? or are there other cars out there without the fuel temperature sensor.

On the cast aluminium fuel rail the temperature sensor should be right next to the back pressure valve where it clamps into the fuel rail directly above the oil filler cap.

Answers on a thread please

Mark

[PompeyTim]

When I first got my S3 there was no fuel temp sensor fitted, but just like you I had the connector & threaded hole ( and it is just that, not open to fuel system in any way). The part is obsolete through Ford and I didn't have any luck with a number of Ford specialists. I eventually managed to get one from ebay but I had to buy a whole fuel rail to obtain it.

In all honesty I can't tell one way or another whether it actually did anything or not. Given this and the fact that they seem to be rarer than front indicators I'd be inclined not to worry about it & leave as is...

[Griffinr]

PompeyTim said:

When I first got my S3 there was no fuel temp sensor fitted, but just like you I had the connector & threaded hole ( and it is just that, not open to fuel system in any way). The part is obsolete through Ford and I didn't have any luck with a number of Ford specialists. I eventually managed to get one from ebay but I had to buy a whole fuel rail to obtain it.

In all honesty I can't tell one way or another whether it actually did anything or not. Given this and the fact that they seem to be rarer than front indicators I'd be inclined not to worry about it & leave as is...

Same here, I was given a sensor by Norman and it made no difference whatsoever.
Rob.

[phillpot]

When I changed from the rusty horrible pressed steel manifold to a nice alluminium one there wasn't a sender fitted and the one from the steel manifold wouldn't fit without a little adaptor I made to lift it clear of the fuel pressure regulator.

I suspect (and hope) it is not too critical?

[Barkychoc]

I would male a temporary 'mini loom' from the appropriate afm to ecu and see if the issues go away.