Having changed a faulty (leaking) EHA valve on my 260e with a second hand replacement it started perfectly when cold. After a short drive, say ½ mile, it failed to start. It seemed to fire once or twice and then die. I was on a gas station forecourt, so not able to wait for engine to cool down again. Replaced old faulty unit ... no problems starting. Has a new ignition distributor and rotor. Is it necessary to readjust idling or EHA valve after replacement? Or do I have a faulty replacement EHA valve?