Well I know how to replace the gps just haven't looked and don't know where they are at or if there is any special steps to do on a psd. My idi was very straight forward! Lol are they under the valve cover? Can I just test with a test light hooked to the postive post and touch the top of unpluged gp? Light means good no light means bad? Also my truck seems like if it sat all day or ovenight it doesent fire right off as soon as the wts light goes off you have to cycle it twice. Its about 40 out. Also will the gps continue to heat if I leave the key in the same position after the wts light turns off. So for example if i turn the key on and the light goes on after 10 seconds and I just wait another 10 seconds before I start will they be heating the whole time even after the light goes out? Would that hurt them? Is it normal for the truck to sound funny when its cold as far as a kha kha kha kha kha noise it is a consistent noise and doesn't sound overly strong but doesn't sound like its going to die or anything?? Also if you try to move it within a few minutes it feels like it has no power. All of the noise and no power issues go away after about 5 minutes of run time sorry for the long posts I have been leaving on the site I just feel unsure of my new truck and have never been around a 7.3 psd but every psd after that and 7.3 idi and it just sounds different at cold start then all others.

GPs are under the butterfly valve covers. You can test them at the vc gasket. Unplug the harnesses at the valve covers. Each harness will have 5 pins. Center pin is injector high side. the pin on either side of it is each an injector low side. Each outside pin is for a glowplug.
The WTS light on the instrument panel is NOT connected to the glowplug circuit. The glowplugs may stay on for up to 2 minutes, so waiting an extra 10 seconds or so before starting is ok. You can actually monitor glowplug on time by watching the volt meter.
After you have checked your GPs and replaced any bad ones you should check the relay. This is done with a DVOM. Check the voltage between the two large terminals of the relay while it is cycling. If you get MORE than 0.3 volts, replace the relay.
The noise and low power when cold is probably the EBPV (exhaust backpressure valve) This is a butterfly valve in the turbo exhaust outlet that closes when the engine is cold, creating back pressure. This makes the cold engine work a bit & warm up quicker. Perfectly normal.