2000 lancer 1.5 auto. Tacho works fine when car is not moving but jumps around when driving. I put it up on blocks and put it in Drive and took it up to 100kph and it works fine. Any thoughts please.

There may be moisture in the transmission fluid that is causing ice to block the valves. When the transmission is hot, change the fuid

Have you ever had the transmission serviced? No guarantee, but I bet it will operate fine if you have the filter and fluid changed.

I would need to hear this knock to try and guess what it is. sorry.

This problem occurs when the starter is getting too hot from being close to the exhaust manifold. It can be fixed by placing a tin shield between the manifold and the starter allowing an air flow around the starter to keep it cool.. If you cannot get one from a auto speed shop/ auto electrician shop then you may have to make one

Your IACV idle air control valve has gone bad . When you put the car in gear does it take off and accelerate to about 50 MPH without touching the gas pedal ? Had the same problem. Part from Mitsubishi is about $435 PN # MR578268. It is about $30 to $50 dollars on any other car. If this is the problem, the IACV is located on the throttle body and is held on with three screws. I purchased the whole throttle body at a salvage yard for $40, took the IACV off and put it on my throttle body. Car works normal for now, I am looking for another spare. If enough people complain to MItsubishi and www-odi.nhtsa.dot.gov

you may have broken the shift cable, that's why it shows the vehicle is in park and won't go in any gear.
put your car in neutral with engine off and try to push it. if it does not move then you know it's in park and the cable is broke

We had tacho installation problem with out 98 lancer with no tacho on the panel. we got a aftermarket one but when we had to wiring it up it needed a tacho signle from the ignition coil. The ignition coil is built into the distributor which made it hard. The 2002 is the same distributor setup as the 98 so you can get step by step instructions with diagrams and pictures from my page, you will see an link that says Mitsubishi Tacho installation. website is www.sureyya.biz let me know if you find it useful.

Goodluck

your battery is dead. attempt to jump off another cars battery please look up instructions on how to do this if you dont know how. make sure to drive your car around after jumping it to help charge the battery, DO NOT JUST TURN THE CAR OFF RIGHT AWAY.
otherwise your battery may just be toast, go to your nearest auto parts store to buy a new battery and have it put in or put it in yourself if jumping doesnt work.

probably burnt or cracked circuit board on back of gauge cluster

i had the same problem on my g/f's 2000 lancer GLXi, (with tacho),
i fixed the problem by putting a jump wire on the back of the instrument cluster,
the fault was in the wiring to the tacho part & i drew up my own wiring diagrams for the cluster unit,
then traced the fault,
looking @ the back of the cluster unit, the top right hand screw for the speedometer,,, follow the track on the circuit-board, there is a link wire UNDER the board (there is a dotted line on top where it goes, i think its the left 1,,, there is 2) this track then goes to the bottom left screw on the tacho,,,
i soldered a small gauge wire from the bottom of the link solder joint (MAKE SURE ITS THE CORRECT LINK, THERE IS 2 SIDE BY SIDE) to the bottom right track on the vertical plug socket (its common pos for the warning lights) this is where the "MIRAGE" & other "CE LANCER" (without tacho) gets its speedometer & gauges power from,

kind regards waz
if anyone needs a photo i will pull out the dash again lol its only 6 screws