Thread: 300Tdi [automatic] idle ripple cure!!

I fixed my 300tdi auto idle ripple/surge today quite cheaply (and properly).

1. Get one of these --> Diesel tiny tach Welcome to Design Technologies and Tiny-Tach (I borrowed one). Forget the tacho, its not precise. This clips onto an injector line and is very accurate.

2. Run the engine until full operating temp.

3. Connect the transducer, set idle speed to factory figure of 720 +/- 20.

This is probably ok in Park or Neutral, but when you stick the auto in Drive, the hunt will return! So...

4. I slackened the throttle cable.
5. I set the idle speed using the proper idle speed adjustment rod (ie not just the throttle cable ferrule) to the lower threshold of 700 in "D". (many autos have the idle set in D)
5. Tighten the ferrule to remove slack.

It idles smoothly in lights at D now, not too excited in P or N. Best of all it drives like a bullet now

By the term surge or ripple, are you meaning the engine revs rising and falling at idle? Mine does that. Sounds like an easy fix.
Tony