speedo cable sensor
Discussion
The speedo cable on my 400SE is bridged under the bonnet by a sensor. If the power supply is connected to the sensor the car will not tickover at under 2,300 rpm.
Disconnected it is fine although the revs take a few seconds to die down to about 1,000. Stepper and position potentiometer are all new, does anyone know where I can find a new sensor.
Tks
Rob
Disconnected it is fine although the revs take a few seconds to die down to about 1,000. Stepper and position potentiometer are all new, does anyone know where I can find a new sensor.
Tks
Rob
Must be Hot Wire ignition ?
90% certain its a Range Rover part. 1988-91
Try Rimmers or one of the Landrover specialists
Bit surprised its giving the problem described.
Its job is to tell the ECU whether the car is moving in a closed throttle condition - if moving it cuts fuel on overrun (less pops & bangs) if stationary (or v slow) goes into tickover mode.
Hope this helps
David
90% certain its a Range Rover part. 1988-91
Try Rimmers or one of the Landrover specialists
Bit surprised its giving the problem described.
Its job is to tell the ECU whether the car is moving in a closed throttle condition - if moving it cuts fuel on overrun (less pops & bangs) if stationary (or v slow) goes into tickover mode.
Hope this helps
David
Edited by djc1001 on Wednesday 27th August 13:36
Edited by djc1001 on Wednesday 27th August 13:39
I'm a bit confused too (especially as I didn't even know there WAS a speedo sensor).
Mine is a hotwire...Chimaera, and at present it has a new speedo cable to gearbox, fitted by RT, but awaiting a new gearbox speedo output cog, which was worn, so no reading at present.
I've now been waiting several weeks incidentally, so maybe it's time to look somewhere else.
Evidently my ECU is happy, as the car runs perfectly at all times.
Mine is a hotwire...Chimaera, and at present it has a new speedo cable to gearbox, fitted by RT, but awaiting a new gearbox speedo output cog, which was worn, so no reading at present.
I've now been waiting several weeks incidentally, so maybe it's time to look somewhere else.
Evidently my ECU is happy, as the car runs perfectly at all times.
grahamw48 said:
I'm a bit confused too (especially as I didn't even know there WAS a speedo sensor).
Mine is a hotwire...Chimaera, and at present it has a new speedo cable to gearbox, fitted by RT, but awaiting a new gearbox speedo output cog, which was worn, so no reading at present.
I've now been waiting several weeks incidentally, so maybe it's time to look somewhere else.
Evidently my ECU is happy, as the car runs perfectly at all times.
The Hot Wire Wedges (and RR's of similar age) have what looks like a mini gearbox halfway up the speedo cable, this is a speed sensor as described above. The speedo is still cable driven whereas I think later TVR models had electronic driven speedos (not sure on that one)Mine is a hotwire...Chimaera, and at present it has a new speedo cable to gearbox, fitted by RT, but awaiting a new gearbox speedo output cog, which was worn, so no reading at present.
I've now been waiting several weeks incidentally, so maybe it's time to look somewhere else.
Evidently my ECU is happy, as the car runs perfectly at all times.
Dependent on ECU and wiring - can believe it will run ok without but 3.9 RR manual states a defunct sensor will effect tickover.
r's
David
Well it is a Wedge of course...1990, just Chim motor, but evidently the sensor isn't affected by the speedo not getting a mechanical reading, as the engine (touchwood 
) runs fine, including tickover.
Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
) runs fine, including tickover.Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
grahamw48 said:
Well it is a Wedge of course...1990, just Chim motor, but evidently the sensor isn't affected by the speedo not getting a mechanical reading, as the engine (touchwood ) runs fine, including tickover.
Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
Interesting.) runs fine, including tickover.Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
Was it Hot Wire pre Chim engine and are you using the original 14CUX ECU or a Chim. verion
What have you done with the 2 wires from the sensor ?
Have also seen one running perfectly well without the stepper motor, just stuttered a bit when the altenator was loaded (lights etc) on tickover. I'm all for eliminating bits / simlifying where possible.
david
djc1001 said:
grahamw48 said:
Well it is a Wedge of course...1990, just Chim motor, but evidently the sensor isn't affected by the speedo not getting a mechanical reading, as the engine (touchwood ) runs fine, including tickover.
Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
Interesting.) runs fine, including tickover.Just seems a bit odd, as I would have assumed that the ECU would be getting a big fat zero for road speed.
Was it Hot Wire pre Chim engine and are you using the original 14CUX ECU or a Chim. verion
What have you done with the 2 wires from the sensor ?
Have also seen one running perfectly well without the stepper motor, just stuttered a bit when the altenator was loaded (lights etc) on tickover. I'm all for eliminating bits / simlifying where possible.
david
It does have the chim matching ECU, but with a different colour something or other to allow for not having cats. (Supposedly a HC motor)
It has a 218/220 Real Steel cam fitted, same time as engine change...about 6,000 miles ago. I wouldn't know about the wires to the sensor, as brummmiewedge did the changes.
I do know that the speedo did work ok up until a few weeks ago, but the new cable is not turning the nylon cog correctly, as the cog is worn.
Gassing Station | Wedges | Top of Page | What's New | My Stuff