Hello. i have just buyed a mb s124 300te 4 matic 1987 and i need some help.

My cars rpm gauge dossent work, what Are normal fails her?

And its not going at idle, its smood Rynning with a little gass but not holding idle. Its a m103 engine.

I got mechanic skills. But not at old carsat this and the k jetronic is pretty complicated system. I understand æ bit of it from school but not enugh. I tried to change ovp rellay but no help.

Im Norwegian so sorry for my english but og some one need more information. Just say what u need.

I tried Norwegian forums but no help