Why does my rev counter keep jumping - 1997 Land Rover Discovery

Low battery voltage can do strange things to the electronics of your vehicle.

Possibly a bad connection on the Cam Sensor. Clean the two sides of the plug with electrical switch cleaner.

https://www.google.com/search?q=2009+suzuki+grand+vitara+2.0+rev+counter+jumping

Sorry for the delay in answering :>D

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check the condition and tension of the drive belt. Check that the battery terminals and posts are shiny clean and tight. Have the battery load tested for faulty cells. Have the alternator tested for output

sounds like an engine sensor try the crankshaft sensor as the rev counter gets its info from that , might be helpful to get the OBD read by a suitable mechanic

may be it is injection pump, try to fix it with injection pump calibrator,

yes rev counter has a problem,. remove rev counter from speedo cluster and take to instrument place to get circuit checked and rectified, give clear discription of symtoms under 3000rpm fluctuates etc.

could be needing replace best to check with the main dealer

Your problem sounds as if the thermo sensor....which controls the air fuel ratio when engine is cold....is faulty. It is a common fault on this model.
This is not an expensive part, and takes only a short time to fit.
Good luck
John

sounds like the idle speed sensor,if your rpm's are idling up and down

Fuel filter or vacuum leak good place to start. Good luck and have a good day.