Chris, It sounds like you need some troubleshooting work done and your mechanic can do this if he has the Bentley manual (big green one). First of all it sounds like you had an idle issue before the A/C repair and the A/C repair is making it worse. The first thing I would check is the throttle position switch. This needs to be working and adjusted properly (Bentley). If that doesn't fix it then check the Temp II sensor (Bentley). If that doesn't fix it then check grounds. I would also be sure that your timing is right. I usually time my engines to 7-10 BTDC. You can do this without unhooking anything (ignore the instructions in the Bentley that talk about having the engine at 1500 rpms and unhooking the temp II, these instructions only apply if you are using a VW special tool that not even the dealers have any more).

If you get these base things right and you are still having problems then the problem may lie with the idle control unit or the Idle stabilizer unit. These units are expensive new so it is better to start with the cheap/free things first.

Hope this helps, Ken Wilford John 3:16

Chris Snyder wrote:

>Good morning list: > >I need some help with my 1987 Vanagon. > >I took my van in to get the A/C compressor replaced and afterwards, my >mechanic didn't like the way it was idling (rough) so he checked the timing and when >he put it to the 5 degrees BTDS it would hardly idle so he put it back where >it was and checked both the idle stabilizer and the little black box behind >the tail light assembly and when he disconnected it would die. also when he >disconnected the stabilizer that sits on top of the engine it would almost stall >the engine so we are guessing they are working but neither of the units are >"Humming" as I have been told they (Or one of them are surpose to do) so then he >attempted to adjust the air flow meter and the idle air screw which did help >the idle but, it's still not as it should be. > >Before he did anything when the engine was cold it would die until it wormed >up and then it was fine except that in park it would have an idle speed of >about 1500 until you shut the engine off then it would idle at 700 until you >drove it a little not, after the adjustments it idles at about 700 all the time >but, it is somewhat sluggish. And not as much power. > >Any help here would be appreciated. My mechanic is not a VW mechanic but a >good mechanic in general and is scratching his head as to what to do now. > >Chris S. </HTML> > > >