Vital Sensors

• While pre-1996 engines don't use quite as vast an array of sensors as their newer offspring, those that they do use are vital. The most important are the crankshaft/camshaft position sensor, the throttle position sensor, oxygen sensor and throttle position sensor. Most of these sensors don't fail outright, they fail intermittently and begin sending incorrect voltage readings to the computer. These intermittent readings confuse the computer, causing it to continuously adjust the air fuel mix to stay within its programmed parameters. This continual adjustment can result in lurching under cruise or acceleration.
  
  

Transmission Fluid Level

• Chrysler transmissions of this era are very sensitive to changes in transmission fluid level, and don't like being run dry. The transmission dipstick has two or three markings: cold, warm and hot. The "cold" marking indicates the lowest acceptable fluid level, and "hot" indicates where it should be under running conditions. If you fill the transmission to to "cold" when it's hot, the transmission pump will start sucking air and starve the torque converter and fluid passages of fluid. This can easily result in a lurch accompanied by a rise in engine rpm. Remember to always check you transmission fluid on level ground, not on an angled driveway.
  
  

Shift Failure

• This isn't a failure of the transmission so much as it is of the shift mechanism in the steering column. Many Chrysler K- and J-body cars of this era (including the LeBaron, Aries, Reliant, Dynasty and a number of minivans) developed column shifter issues, wherein the car would either refuse to engage overdrive or would slip into and out of it. The resultant lurch was either a result of the engine hitting the rev limiter in third gear or of the transmission repeatedly going into and out of overdrive. The only permanent solution here is to take the steering column apart and repair the shift mechanism.
  
  

Vacuum Leaks

• A number of transmissions from this era used a vacuum-actuated modulator that uses engine vacuum to control fluid pressure and shift firmness. If your vacuum line is leaking or cracked, the transmission may receive an intermittent vacuum signal and continuously adjust fluid pressure to compensate. Once fluid pressure goes up, the engine engages more fully and vacuum drops. Once vacuum drops, the leaking hose allows the pressure inside the line to equalize to atmospheric pressure and the transmission fluid pressure goes back down. This pressure fluctuation can manifest as lurching under cruise conditions.
  
  

Boost Fluctuations

• Many LeBarons of this era rolled out of Chrysler's Delaware and Missouri plants with turbocharged engines. Turbo pressure fluctuations can cause lurching just like any vacuum leak. These pressure fluctuations can come from a leaking turbo-to-engine tube, a leaking intercooler or a malfunctioning wastegate. Leaks in hard components like the intercooler will usually result in a general drop in boost pressure and horsepower, but leaks around soft rubber components can result in lurching. The wastegate is a boost-actuated valve that allows exhaust to bypass the turbo at a pre-set pressure level. The wastegate solenoid connects to the intake system via a rubber vacuum line; if this line develops a leak, the wastegate will open and shut repeatedly, leading to lurching and a shudder during acceleration.