Nissan Repair: 88 Nissan Pulsar misses on highway, nissan pulsar, exhaust pressure

Question
My 88 Nissan Pulsar (42,000 original miles) feels like its missing on hills at highway speeds. It has also started doing this in the city, also on hills. The car had the timing belt replaced and the exhaust system replaced 2 years ago. More recently, it's had plugs, fuel filter, fuel system cleaning, O2 sensor, air filter. My mechanic found a knock sensor code in the computer and a frayed knock sensor wire. That was fixed and he said the sensor was fine. He also tested the exhaust pressure and said it was fine as well. This has not solved the problem. Any suggestions?

Answer
Mike,

Have him check the distributor for oil on the optical shutter wheel.  This is inside the distributor under the cover that is under the rotor post.  The oil seal fails and oil sppes up the shaft to the optics and that could cause the problem you describe.  The solution is a rebuilt distributor.