OT) surging at idle

[photo@intrex.net (Bill Collins)]

What year cabby? (or more to the point CIS or Digifant?)

I just fixed something like this on my '90 (Digifant)  The idle adjust screw was set way too high, but normally the computer brought the speed back down.  I disconnected the electrical connection to the idle stabilizer and adjusted the idle to about 900 RPM.  When I re-connected the stablilzer, the idle stayed at 900 and the surging hasn't returned.

I just helped someone diagnose something similar on a Digifant Jetta, but in this case the idle screw did nothing, so there must be some kind of blockage in the throttle body.

If your cabby has CIS and an idle stabilizer box that plugs inline with the ignition module (I don't know which years they used this, and it may have been a california only thing on the Rabbit), you can have the same kind of problem.

Bill

-------------------------------
     along with tons of work to the rocco, I've been working on the wifes 
 cabby as well.  I got running again lastnight (it's been down for a 
 month for many minor repairs) and a one problem remained. 
     At idle or right after you come off the throttle, the engine will 
 surge up and down and it's a bit more then your standard idle hunt I 
 think.  This is on a normal stock 1.8 8V cabby.  I still need to replace 
 the O2 sensor on it, but aside from that, what can cause the surging.  I 
 want all suggestions since I need for this car to run very well if my 
 wife who doesn't look at the damn gages is gfoing to be driving it.