my 1988 318i e30 has got some problems, when started it will run fine start easy and idle good, but if i turn it off and try to start it again it is hard to start and when it starts it may idle high (not always)(3000 rpm) if i then turn it off and restart it may do it again or run fine?? then when running fine i can slowly accelerate up to 3000 rpm where it will start to miss fire, i can then turn it off and start it again to find out that it revs freely with no miss fire?? it will probably be a sensor on its way out, but which one is it? or if anyone has another idea please let me know? thanks for your time. this is my first post so i hope it has not been covered somewhere else as i can not find anything that helps me..