Isuzu Repair: 2000 isuzu amigo @ idle revving up and down, isuzu amigo, fuel pressure

Question
When sitting at stop light, the engine revs for just a few seconds and then slows back down.  It cycles every 45 to 60 seconds...and seems to do it more on low fuel in the tank than when full.  Ideas?

Answer
Bad intake gaskets/vaccum problem. Low fuel pressure and or clogged fuel filter puls injectors David. I would have all of these checked and one of these I am sure is the culprit. Although if you have anymore questions please don't hesitate to ask okay?