Ignition switch questions


Active Member
Aug 7, 2008
Hi guys posted this in the general section and got nothing so reporting here. I have been fighting a missfire and dieseling problem for a few months . Been threw injectors , injector harness , ECM , maf and then found a wire from the alt was open and grounded. Happend to be the brown wire that runs to the ignition switch . So I cut and replaced the wire but am still having the same issues.
So my question is , could a ignition switch that has gone bad cause a slight miss a crossed the entire rpm range and a car to diesel every time you try to turn it off .
Thanks in advance for any help.
Anyone else have any thoughts on if this could cause a car to diesel (run after the key is turned off for a few seconds ) .
Got a timing light? If so hook it up and watch if it still fires after you turn off the ignition.
But you say dieseling, so it's bucking belching etc.?
Or does it run on for a few seconds?
dieseling is usually caused by hot spots in the combustion chamber- usually the spark plugs. of course, it also needs fuel to do it, so maybe you've got a couple of injectors that aren't sealing off when you kill the power.. does it hold fuel pressure?