Q&A: > Anybody ever figure out what RB meant by "zero the dial gauge w/ a > 1mm preload" - if you do, there's no way you'll even get close... > What they mean is, set the engine to TDC, and insert the dial gauge into the pump. Continue to push the gauge in until it reads about 2 mm. Lock the gauge in place, then rotate the dial face so the pointer is at zero. You must have a gauge that has about 5 mm of travel, and reads to 0.01 mm. These are not cheap, nor easy to find. (But neither is a dealer who will take the time to do the job really well.) The reason for the preload on the gauge is to ensure that the gauge contacts the pump plunger continuously while you are moving the engine around. Otherwise you will not be able to locate the start of injection point accurately. Hope this helps...