Engine keeps running after key removal

[FATRAY]

I have an 88 with the 2.5l. Recently the engine keeps running after turning off the key for about 3 seconds, or sputters till it dies. This varies, sometimes it will turn off, but if hot, stays running. It's more embarrising then an real issue to hear the engine clunk clunk till it shuts off.

What would cause this?

I've recently changed the plugs, wires, & cap.

 

[dieselearl]

if did not have the problem before you change parts . you may have a plug problem being a hotter range. the correct plug is champion RC12LYC{412}