Road speed sensor help

[red griff 500]

Griff interloper needing help! I'm getting wild fluctuations of speedo readings - it's sometimes reading correct speed and sometimes reading zero. Also, tickover is playing up, sometimes ok, sometimes too low at @ 500rpm and a general reduction in power.

The bible suggests that the road speed sensor is suspect in this case as it feeds the speedo and also the ECU. It says that the sensor is in the gearbox on an SD1 box (apparently it's at the diff with the T5 box).

Anybody any experience on

a) exactly where it is on the SD1 box?

b) how to clean it and reset it etc

thanks in anticipation.

Steve

[K4TRV]

My 93 Chim with Rover box has the sensor in front of the diff input/prop shaft- a starred/spoked wheel affair with sensor above it. Bit of a squeeze unless you get the car onto a ramp, but if you've long arms you could reach when on jacks, I suppose.

No idea on the "gap" - Mk1 eye-ball should determine if it's too close or too far ??

Also check wiring around battery, as I believe it goes to ECU before parallelling to speedo - bad connection ??

Trev McM