Sensor Help Required.
Sensor Help Required.
Author
Discussion

boroboy

Original Poster:

35 posts

233 months

Thursday 5th July 2007
quotequote all
confused
Does anyone out there know much about the Fuel Rail Temperature Sensor on an S2. It is the one screwed into the fuel rail next to the Dissy cap.

Is it a Sensor, ie Resistance changes with temperature, or is it a Switch, ie its on or its off.

I have put a multimeter across the terminals of mine and it is open circuit, which if its a switch may be Ok, but if its a sensor its not.

I have checked the Bible and it doesn't give any clues on how to test it and I have checked the Haynes Granada manual and that is even less help.

Any Help would be appreciated.

Jed-S

660 posts

245 months

Thursday 5th July 2007
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I've just put a meter across mine (S3) and it is open circuit at room temperature.

Sweet Thunder

220 posts

250 months

Thursday 5th July 2007
quotequote all
According to the manual it is a switch. Normally it's open, it closes at high temperature.

boroboy

Original Poster:

35 posts

233 months

Thursday 5th July 2007
quotequote all
Thanks for checking yours for me Jed-S and thanks for the info Sweet Thunder, which manual did you find that in.

I might take mine off and test it in some boiling water as I believe 90 degrees is the point the EEC starts to over fuel.

Sweet Thunder

220 posts

250 months

Friday 6th July 2007
quotequote all
The manual I have is a Ford Service Training manual, Technicians Product training for V6 engines 2.4 and 2.9. This was used by ford to train technicians when the 2.9 V6 came out in 1986. These are available on ebay every once in a while. Worth having, together with a copy of the bible and parts of several Haynes manuals. (Still looking for the gearbox chapter of a Capri manual, or a proper Ford manual for type nine gearbox).

boroboy

Original Poster:

35 posts

233 months

Sunday 8th July 2007
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Cheers for that Sweet Thunder, I will have to keep my eyes open for one of them. Trouble is though, everyone who has read this will also now be looking for one. Doh.

I did test my sensor by dangling it it boiling water and sure enought at about 92 degress it changed state to 0 ohms and changed back again to open circuit once the water had cooled down to 73 degrees, so that seems OK.

Barkychoc

7,848 posts

233 months

Sunday 8th July 2007
quotequote all
Might be worth saying why you are testing it.
Do you have a specific problem ?
If so pretty likely someone on here has seen it before.

boroboy

Original Poster:

35 posts

233 months

Sunday 8th July 2007
quotequote all
Yes my darling motor is acting up a bit from time to time.

She has a habbit of misfiring / kangarooing usually on partial throttle often acompanied with a back fire, but not always. If I have to stop while she is having one of these strops she cuts out, but up till now has always restarted. I have found that by unplugging the ECU for a couple of minutes has her running fine again for a couple of runs before the problem starts to creep back.

I have replaced the throttle pot and the ECU coolant temp sensor. I have also cleaned and tested the air flow meters, including the air temp sensor, and both seem OK. She has also had a new coil, rotor arm and plugs. She also used to tickover a bit erratically but that was cured after I found one of the air flow meters had been sticking. I have also had the fault codes checked on the ECU but nothing is showing up.

I have just been working my way through the sensors when I found the Fuel rail sensor was open circuit, hence the original post.

Barkychoc

7,848 posts

233 months

Sunday 8th July 2007
quotequote all
Can someone answer this.
Does the 2.9 fuel injection ECU 'learn'.
So when the ECU is reset it starts with baseline data, then starts to adapt to the sensor readings, which would explain why its OK after a reset, then presumably its getting duff information from a sensor, trys to adapt & fails.

Tell me if this is rubbish !

boroboy

Original Poster:

35 posts

233 months

Sunday 8th July 2007
quotequote all
scratchchin
Thats exactly the theory I am working on at the moment, I just can't find anything wrong. Every thing I have tested seems to be OK.

ketvrin

3,504 posts

238 months

Monday 9th July 2007
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I read somewhere on here (I think it was Tvrgit) that after a battery has been disconnected it takes 4 or 5 hot/cold cycles before the ECU "maps" correctly, during that time you can see symptoms which are like those of a duff throttle pot... sounds like yours is the other way around and becomes duff after 4 or 5 cycles ???