'99 F250 PSD: Cold start problems getting worse

[pac'em out]

Hey everyone,
My '99 (89K miles, superchips tuner) has trouble starting unless its been plugged in. I've been reading alot of the posts and can't figure out what to do. When starting, it cranks with plenty of power, and sounds like it almost fires then spudders out. After cranking 5-6 times it usually fires up with a puff of white smoke. This has been ongoing for the last year and I'm finally ready to do something about it. I've read the tech file on testing the glow plug relay but I don't understand it. Does anyone have more straight forward directions how to test the GPR? Any help is much appreciated! Take care.

Tim

[Dave]

Using a Voltmeter. test across the two big terminals on the relay. have someone turn the key on so that the relay can start. If the voltage is the same across the the two terminals or within about a volt the relay is good. If the drop is more than that or no voltage at all its bad