1997 Plymouth Voyager

I have the above vehicle, when I start it up every morning I have to keep my foot on accelorator and then have to keep foot on gas and use break when stopping or van dies. After van warms up to the half way mark it keeps running on its own, one day I looked under the hood and went by the idler arm, and touched the cables and van stayed running while someone else was inside the van. I key tested the vehicle for codes and found none, I was wondering how slack the cables are suppose to be and if there is any way to tighten the cables they are extremely flimsey, if not what do I have to replace? This is an ongoing problem that is driving me crazy. Please help.

Thanks,

Kathleen