Alright, So a while ago my truck wouldn't start cold. So I tested the gpr and it showed good, but I tested it again and it wasn't good. So I replaced it. Truck started and ran fine for oh I'd say 2 months. Now it's doing the same thing. I wouldn't think it's the glow plugs because replacing the gpr worked for a little bit. Is there something in these trucks that eats up the GPR's?
Also, I was in a situation that dictated I HAD to have use the truck last time it wouldn't start so I had to shoot just a litttttttllllleee bit of ether in it. I waited 3 minutes with the key on so as not to shoot the ether in with the glow plugs on. I know this is bad for the truck, but could just one shot have messed things up?
I'm fine with leaving it plugged in for now till I can get some new glowplugs, but are the glowplugs really the problem?

 

that little bit... probably not. check the voltage at the VC plugs and see what it is there compared to at the relay. then if it checks good then look into glowplugs. MOTORCRAFT ONLY, please.

 

I did and everything checked good. I tried to cross the two terminals and it didn't start so I'd assume glowplugs, I just thought it was odd how it went back to working for a few months. Oh well, what can you expect out of an 12 year old truck. And I can get the motorcrafts at damn near cost

 

it could be the plug came of the glow plug. that happened on my 96. but either way. VC's have to come off.