200TQ rough running/stalling

[Phil Payne]

> I have a problem (again) with my '90 200TQ. Usually it starts fine,
> sometimes, when it's warm, it will not start without pressing the gas
> pedal. In addition, it runs really rough and stalls below 2500 rpm,
> but over 2500, everything is fine. It will "pop" and almost stall
> below 2500 rpm, in addition, the tachometer needle jumps up and down
> like crazy, from 1000 to 3500 rpm when running around 2500. This makes
> me think "ignition". Where do I start? I'll pull the codes tomorrow,
> but any clues except sensors?

Could be anything.  I had this on mine, and in my case it turned out to be a VERY loose #1 injector seat.

--
  Phil Payne
  http://www.isham-research.com/quattro
  +44 7785 302 803
  +49 173 6242039