Chevrolet Repair: 1999 gmc savana van, gmc savana van, gmc savana

Question
van still runs after ignition is shut off, already replaced the ignition switch and van is still doing it.  

please help

Answer
Hi Dianna... is it run on, or does it stay running... if it's just run on try using a higher octane fuel. run on is caused by fuel combusting in the cyl after shutdown...if it is staying running then some where in the ign circut you have a power crossover...in other words the power side of the on side of the switch is staying live even after you turn key off. start van then shut off. probe the on side of the switch with a test light... should be no light...if there is then you will need to trace that circut and find the short to power.power is back feeding thru that circut... try looking at any connections that may have a crossover point...like at the starter. look for a corroision build up that could be bridging two wires or connection points. same at the fuse panel... you say you changed the ign switch. check wiring at the plug in at that switch. make sure that switch is adjusted properly so that it is not staying in the run positation and the rod is moving all the way to off...hope this helps