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On 19 Sep 2005 at 22:09, J. Jonik wrote: > Suspecting that Vacuum Advance wasn't advancing > smoothly and nicely enough, thought it was time to > take apart and clean the distributor...T 3 71 Fuel > Inj. > Out tumbled bits of a small broken "washer" or > bushing...the kind made of some solid plastic > insulating material. It was brittle. > What's the source of this thing? Anyone? I THINK, > based on size (about 3/8s of an inch...diameter of a > cigarette) it came from beneath one of the two > pivot/spring posts in the trigger contacts. It's a phenolic washer. Odd, I've never seen those break on the FI trigger points. > Q: > a) Is there a difference from side to side in trigger > contacts? Or, ought both be identical? They should all be the same, or rather mirror images of each other. > b) What might be effects of a missing insulating (?) > bushing? You don't want the contact to slip off the side of the fixed point, and you don't want anything to short to the base. > c) Are trigger contacts Dead Meat w/out this > insulating bushing? (Can't replace w/out grinding out > a rivet and somehow replacing.) Early FI trigger points did not have the little washer at the top of the pivot. You can just grind the riveted over end of that pivot off and throw the washer away. Replace the phenolic washer with a nylon or phenolic one that you can buy anywhere. > d) Is there a way to electronically test trigger > contacts to make sure they are properly insulated or > whatnot? Just use a standard VOM or DVM. > Effects were...uneven, hard to adjust,idling... > tending to the fast....and not so smooth transmission > when starting up and while slow driving after long > trips. Something was wrong. Subtle. But what? This doesn't sound like anything in particular that I recognize. I HAVE had some trouble (2 such sets of trigger points over 35 years) with trigger points that seem to have been poorly made. I'm setting up a test jig to check these now. The main thing to check is to verify that each point is closed for just under 180 deg of rotation (maybe about 160 deg each) and that the spaces where neither is closed are about the same size. You can do this check with a VOM and with the trigger points installed in your dist, which you're holding in your hand. Alternatively, you can send them to me to check, but that will take longer and cost you postage. I wouldn't charge for this, but I plan to start checking it on every dist I rebuild from now on. -- Jim Adney jadney@vwtype3.org Madison, WI 53711-3054 USA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ List info at http://www.vwtype3.org/list | mailto:gregm@vwtype3.org ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~