fill the fuel filter up with auto trans fluid, and start the truck. let it idle for 30-45 seconds, then shut it off. leave it sit for at least 12 hours, 24 is better. then fire it up and drive it like you stole it.
the ATF and sitting will clean out the injector pump and injectors. if this does not help, then you may need a new injector pump.
but it usually works.

 

Thank you for the input Tom. In fact, found this information while doing some searching last night. Was going to do this at the end of the day today when I'm done working on the truck. Only problem is, the truck is not inspected and I'm not able to drive it the following day. Also.. I'm going away for a week. Would it be bad for the system to have the ATF sit in the lines for a week instead of 24 hours?

 

nope, not at all.
you can also let it sit for 24 hours and fire it up and let it run for 5-10 minutes, and see if it runs better.
then when you get home ATF it again. i do mine once a year, and push my injectors and pumps to 150- 175k miles before changing them.

 

Thank you for the ATF tip. I will do that after I get this starting issue figured out. Here's where I'm at:

I checked the resistance in ohms on a bunch (but not all) of the glow plugs just to see where I was at. They were spot on the with new ones I purchased (but didn't install).

I've got the glow plugs working and they do start the truck now without plugging the block heater in.

Sometimes, the WTS light does not come on at all. However, when it dose, this happens:

With the key in the on position, the WTS light comes on for about 8 seconds and then goes off. At this point the relay that's on top of glow plug control module clicks about 8-10 times in about 5 seconds worth of time. The glow plug voltage doesn't go to zero, it starts at eight and then jumps with the clicking. The voltage jumps no more than 2 volts and goes from 8 to about 10 volts during the clicking. Then, everything stops. No more noises, no more voltage.

Is it time to replace the controller, or check elsewhere? I've been cleaning contact points for wires as I replace parts. Trying to eliminate those potential issues.

 

nope, that is the controller working properly. the clicking is an "after burn" to keep the glow plugs hot but not glowing after it starts, to help the engine stay running.
with an outside temp of 60 to 80 degrees, around 8 seconds sounds about rite. the colder it is the longer the wait to start light will stay lit.
i have seen 15+ seconds when it was below -10 degrees.
the glow plugs will activate until the block temp is around 110 or 120 degrees. after that, they shut off.

 

Now I just have to figure out why the WTS light sometimes doesn't come on and the glow plugs don't light up at all, randomly.

 

cold engine, or warm/hot?

 

the engine dyeing on deceleration can be a sticking metering valve. atf may unstick it or other fuel additives may help or it may need a IP. remember its a diesel and won't always jump to life, if it starts it's a good day..

 

The No-Start happened on a cold engine. I don't know though... Went out there today and the truck acted like it was brand new. I cycled the glow plugs twice. They acted normal: Cycled on for about 8 seconds each time (Without any extra clicks as I previously described) and it fired up in less than a second.

 

I have a 90 7.3 idi 5 speed extended cab 4x4. As tjc suggested atf in filter over night works wonders. When I have symptoms it stalls on de acceleration and when I push clutch pedal in but all that goes away with the atf trick. It has been my daily driver for the past 6 years and it's great not in best of shape but gets me from a to b.

 

I would check and clean all electrical connections in the glowplugs/controller/relay harness first

 

Roger that. ATF is sitting in there as I type.