Nissan Repair: engine miss, shaft seal, sheel

Question
I'm having problems with my '88 Nissan PU, with the four cyl z24i engine. It has developed a miss, but only when the vehicle is cruising at speed. It idles well, and runs normally when it is accelerated, but "bucks" and jerks (like it was running out of fuel) when I try to hold a given speed, at any speed.
This vehicle is in the Bahamas, and tech help is hard to find.
Thanks.

Answer
Richard,

The distributor is probably going out.  Inside, under the rotor post there is a cover that hides the optical pickup.  After this many years the shaft seal in the very bottom of the distributor has started to let too much oil enter the distributor.  The oil gets onto the optical shutter sheel and you get this nice miss.  Check it out and if you find oil on the optics or shutter sheel replace the distributor.