I have an 89 F350 with the 7.3L non-turbo diesel. My problem is that when it is cold out I have to cycle the key several times to get it to start if I haven't started it for several hours or plugged it in. Sometimes I have to cycle the key up to ten times. The truck will always start though. I know that the glow plugs are good and have replaced them recently. I have heard that there are several relays that could be causing the glow plugs to be turned off before they are ready.

Does anyone know what might be causing this problem.

I have replaced the relay that is behind the passenger side battery. The one that controls the voltage from the alternator to the battery that allows them to charge.

The glowplug controller is on the intake all the way in the back. Follow the wires from the glowplugs to find it. If should be energizing the glowplugs for 10 to 15 seconds, if its less than that then there is a bad plug(even one bad plug can cause probs) or the controller may be going out. If the batteries do not allow the engine to spin fast(as in alot faster than a gas engine) then you may not build enough heat in the cylinders to ignite the fuel as well.
If your batteries are good and all 8 plugs show to be good then I would find out about possibly testing the controller.

http://forums.thedieselstop.com/ubbthreads/

Thanks Fractalman I will double check everything you said and I think that I am going to copy and paste this thread to the Dielsel Stop and see what their opinions are. I have known about that website for quite awhile but spaced it out. Thanks guys.

Sean