Intermittent problem with the speedo

[jasonsteptoe]

Hi,

I have a 2000 (w reg) Chim 400 and having an intermittent problem with the speedo. At times the speedo doesn’t work but when the car is driven harder the speedo pings back into action. The car also runs a little rough when the speedo is out and doesn’t want to idle that well.

Any ideas on what the cause is?

Thanks, Jason

[.Mark]

Doubt the running rough and speedo are connected to be honest, probably coincidence.

My speedo did the same as yours and then promptly packed up forever. I needed a new sensor at the diff end.

[K4TRV]

Speedo sensor feeds speedo (obviously) and the ECU (not so obviously, but ECU needs to know if no throttle is required whether you are at rest and hence moderates tickover or going down hill, no fuel required!!).

So, if your speedo is not working AND you have slow running/tickover issues they are related and you need to get under to front of Diff and check speedo sensor gap.

Do an advanced search.

HTH

Trev

[jasonsteptoe]

Thanks, do you know how close the sensor should be set to the wheel?

Jason

[jasonsteptoe]

Thanks for all your help, all sorted, it turned out to be a loose connection under the dashtop.

Jason

Edited by jasonsteptoe on Monday 15th August 19:47

[pbaker43]

if you have one of the original sensors then I would consider binning it. I had the same problem the speedo was all over the place, some times the number dials would rotate. I checked my sensor and it was 12thou from the gear wheel, but the wheel cut in to the face. Finally brought a replacement from Steve Heath and it works a treat. 3mm gap (no danger of damage) checked that the led pulsed on every tooth, never had a problem since speedo works, dials rotate.

As for your other problem no sure, I found that it is better to sort each problem as it comes along use a good method of checking each component that it is functioning correctly, before replacing many different items at a huge cost.