I wash my Jackaroo with engine degreaser and washed it down with the hose, now when I start the engine it won't idle or if I'm driving on the road it will stall, can somebody advise what could my problem be? And how I might be able to fix it?

You may have contaminated your Oxygen Sensor (HO2S) or oxygen sensor connector with emulsified oil or grease. Oil or grease residue will kill an oxygen sensor faster than lightning. The same thing could have happened to other sensors, such as the Throttle Position Sensor (TPS) or Idle Air Control (IAC) Sensor. See if you are throwing any codes. Additionally, remove the distributor cap and allow any accumulated moisture to evaporate.