Nissan Repair: 1991 Nissan Maxima Stalling and other relatied problems, nissan maxima, optical pickup

Question
Hello,
 I have a 1991 Nissan maxima and I am having problems with stalling. The car has about 225,00miles and has been a great car until now. Frequently the car will go into a stalling fit. the car will stall repeatedly and then be fine for hours then go back to the problem. When its in its stalling tantrum. I will try to give it gas to help it from stalling and the engine will not go above 2000RPM. This happens in gear and out of gear. The problem seemed to be gradual and has now gotten out of control. The spark plugs have just been changed along with the fuel filter. My father and grandfather ( who are mechanics) as well as the mechanics at the shop , I use, are all at a loss for words as am I. Please help! Thank You
                      Michael Anderson

Answer
Michael,

Check the intake hose and see if it is cracked.  This is the black hose from the air meter to the filter box.  Another area to check is the distributor for oil on the optical pickup.  The distributor uses a optical pickup and shutter wheel that tells the computer when to fire the plugs.  If oil gets past the distributor's internal seal the optics get coated and the engine runs like you describe.  So, I think it is one or the other.