BACKGROUND: I have a '73 2.0 with FI that I bought in April and it has run smoothly since purchasing until 3-4 weeks ago. So far, it's been a positive experience. I've done a few minor things myself to make the car safer (H4 headlights, H3 fogs, new Repa seatbelts, etc.). I have not touched the engine and have always left that stuff to professionals (aside from minor things like an oil change), but know eventually I will have to roll up my sleeves and learn how to maintain this car myself (as much as possible) to keep her on the road and running smoothly. Apparently, that time is now as I've had two issues come up that are preventing me from driving her.
ISSUE #2: this issue began just yesterday ... I started her up (cold start, first start of the day ... was hoping to troubleshoot the heating issue above) and immediately it started idling very high (2,000-2,500). Then the longer it sat idling, the higher the idling went (up to 3,000-3,500). I took it for a short drive around the block, but the idle never dropped even after warming up. Made it impossible to drive sitting at a light idling at 3,500. I checked the gas pedal (nothing seems sticky or stuck - gas pedal springs back fully when foot is removed). I popped the engine lid and I don't see anything sticking to the accelerator cable on the other end. I did noticed the voltage gauge was high too - it was at 13.5-14. Is the high voltage causing the high idle or is the high idle causing the high voltage? What could be causing the high idle out of the blue like this?
Thanks in advance for your help/suggestions.