yboy82 10/21/2010The common possible causes of your vehicle’s trouble are plugged/damaged PCV valve, damaged/clogged PCV hose, damaged/fouled spark plugs, defective carburetor (if equipped) and damaged/defective accelerator pump diaphragm (if equipped with carburetor). Diagnose your vehicle with a scan tool to determine if there is a stored trouble code in your vehicle. Even if your check engine light is off don’t assume that you don’t have any stored trouble code. The only way to verify for stored trouble code is using a scan tool to diagnose your vehicle.
AWACS E3 Sentry 10/21/2010It maybe because you have a vacuum leak, to look for vacuum leaks, you need to connect a source of compressed air (approximately 10 psi will do it) to the intake manifold with the engine not running and listen for air leaks.
Hmmm no engine light...
yboy82 10/21/2010I'm sorry for my answer,your vehicle uses a diesel fuel so your vehicle isn't equipped with spark plugs and carburetor. If its diesel did you consider overhauling your injection pump? The strainer inside your pump may be clogged or dirty.