Nissan Repair: 1992 nissan sentra engine problem., nissan sentra, vacuum lines

Question
My sons car as been chugging or feels like it is going to stall while driving down the road. Took the car to a dealer whodid an analysis on it and it stated that the fuel pump 1/2 pressure it should have. Need to replace pump first, then check for possible broken vacuum lines. Now we have replaced the fuel pump and replaced a lot of vacuum lines with new lines. A day later my son told me that the car still wants to stall out( fells like engine has no fuel ) or chug at 80 kmph. Need help to stop this problem.

Answer
Check the distributor for oil in the optical pickup.  I had one where the seal went on the distributor allowing oil to get into the pickup.  This is under the cover that is under the rotor.  To get to it you have to take the distributor off and then take the cap and rotor off.  There are two screws that hold the cover on and once these are off you can see the disc.  It looks like a mineature CDROM with a few holes in it.  Well, the oil gets into the holes and blocks the LED intermittently and this makes the engine run rough.