Volkswagen Repair: Rough Idle problem, vacuum leaks, vw passat

Question
Hello Ryan, I hope you can help me out here, okay I have a 1990 VW Passat 16v. Had it since new, now has 189k. Timing belt snapped and bent some valves. since mileage was high but car is in perfect condition went ahead and had the top end redone. after car has great power but will not idle correctly. Idles really rough, but when accelerate past 1200rpm car engine runs fine. Mechanic cannot figure out what is causing the rough idle. It idles like it has a monster cam. Had new igintion wires put on, doubled checked the timing. The mechanic is now leaning torward a bad o2 sensor or bad injectors.. Can you help me out.. thanks

Answer
Biggest culprit in these cars with a  bad idle is the switch on th e throttle body that tells the ECU that the throttle body is closed.  Check to make sure that the switch works with a continuity tester.  I had one that would work when the car was cold then become intermittent whe the car was hot.  Also inspect all the intake boots and hoses for vacuum leaks.

Good Luck,
Ryan