I turn the key and nothing happens, no glow plugs, nothing. After wiggling and jiggling the key a while the glow plugs will come on but the engine wont turn over. Have to play with the key more and then the engine will finally start but will turn off as soon as I let go of the key. After about 15 minutes of this wiggling jiggling act it finally stays running. Thinking it is a corrosion or ignition problem. Would like some help in this matter.