Hyundai Repair: no power, out of whack, camshaft

Question
niece has a hyundai....not sure on year and model...early 90's....it will start and run fine while in park or neutral(automatic)...when you pull it down into drive ,it acts like it has no power....have to pat the fuel to get it to take offf....have replaced fuel pump.everything seems to check out good....can the cat convertor be clogged up? any answers would be helpful...thanks

Answer
Could be the catalyst.  Camshaft timing could be incorrect.  Many of the cars of your vintage had adjustable ignition timing.  If that's out of whack enough, it could be causing the problem.  I've also seen some cars around this time have worn crankshaft timing belt sprockets.

Can you tell whether it's misfiring?