[LauraBoston]

hey,
i see this a lot in caravans, never seen it in a jeep. i'v always come down to changing the fuel pump (but the problem is the pressure regulator). Or, it could be a restriction in a line. If you can get your hands on a fuel pressure tester, see if the pressure is high...then you know it's a pump.

Otherwise, Chrysler says it could be:
O2 Sensor
O2 shorted to ground
O2 heater operation
TPS voltage greater then .92 w/throttle closed
TP sensor sweep
Map sensor operation
ETC sensor operation
Engine mechnical
fuel pressure high
or PCM

Personally, I'd start with the fuel pressure.
A vacuum leak you'd normally hear...usually they are loud, you can get some carb cleaner and spray it arond the intake and what not, and if the engine surges it has sucked in some carb cleaner and you know there is a leak around there...good luck.

	Throttle position sensor A throttle position sensor (TPS) is a sensor used to monitor the position of the throttle in an internal combustion engine. The sensor is usually located on the butterfly spindle so that it can directly monitor the position of the butterfly throttle valve. The sensor is usually a potentiometer and therefore provides a variable resistance dependent upon the position of the butterfly valve (and hence throttle position). The sensor signal is used by the Engine Control Unit (ECU) as an input to its control system. The ignition timing and fuel injection timing (and potentially other parameters) are altered depending upon the position of the throttle, and also depending on the rate of change of that position. For example, in fuel injected engines, in order to avoid stalling, extra fuel may be injected if the throttle is opened rapidly (mimicking the accelerator pump of carburetor systems).