Hey, I have a 91 Toyota Pickup with a 22RE engine. For a while I was noticing that when i hit the brakes at idle the truck would rev up and down consistently. Eventually that went away and now I just experience a rough idle. It starts easy everytime with one exception. One time I was up in the mountains at 11k feet and it was 30 degrees out and the truck didn't want to start. It took about 2 minutes of cranking over for it to start. I checked the plug on the MAF and it seems to be fine, when I disconnect it, it shuts off. It acts like the idle just needs turned up but the hard start in the mountains makes me wonder. Any ideas? Thanks

 

Please search...so many threads about this out there..."surging idle"

 

Also vacuum leaks, maybe around the brake servo since it was doing it when you pressed the brake pedal.