My 92K 4x4 has an erratic speedo and rev counter plus its mis firing slightly too. Any ideas? Have checked and cleaned the three plugs at the back of the engine and the idle control plug too. Any help appreciated thanks

 

Try the ignition module, it won't cure the erratic speedo though that's cable operated,

 

ok thanks

 

Check alternator.

 

Check the engine wiring loom plugs behind the cylinder head. They can cause a misfire and jumping rev counter.

 

New speedo cable sorted mine

 

ive had jumpy rev counter with a faulty coil

 

thanks for the replies