E30 Zone

hello there i wonder if any can help me on two technical points i have. first i chipped my ecu about a year ago i now want to install the orignal one back is it a case off just fitting and driving or is there a setup to follow. second my speedo some time stops and starts i have heard that the clocks have a battery in them is this true and do you think this is the promblem . and were is the battery on the clocks located thanks people.

Re-fitting the original chip is just a simple change over and away you go, I have always noticed a huge flat spot the first time you take the car out at about 2500 revs then all is ok.
Does the speedo tend to jump about at all, this is usually the cables from the diff need replacing.
If not you have to take the cluster out and the SI board is at the bottom.

hi thanks for reply speedo jumping about was how i was trying to explain my promblem so it sounds like the cable is first call

sorry about spelling

I've got same problem with mine, just haven't got round to it. If you pull the wires you should in feel 1 or both "stretch". Try and renew as much as possible.
Remember not to touch the legs of the chip either as this can shag it.
All the best mate.