what are the running characteristics of a weak spring? no fuel pressure guage but does it make truck run rough at idle or anything noticable before you lose injectors

 

Not really. You wont notice a single difference in drivability until its WAY too late. It wouldn't be an issue at idle usually because there is no load on the motor and a very low demand for fuel. Fuel pressure usually drops way off when you're on the skinny pedal hard. If your spring is weak it just wont let system build enough pressure. These springs wont hurt anything, anyone can put one in, but I just hate seeing people spending un-needed money on something that doesn't even need fixing.

Fuel pressure gauge should come FIRST.

 

going to do the ford spring. Fuel pressure is fine, but the one time it won't be is when I am out in no wheresville USA.

 

It will take some time for injector damage to occur. The spring isn't going to weaken up all of a sudden, it happens over time. Just keep an eye on fuel pressure gauge, when it starts dropping, order the spring. Simple!

 

I go up North for months at a time. You have what you brought with you. You are not going to make it the 6 or 8 hours to a dealership to get the part you need.

 

And there is no address to have anything shipped to?

Obviously everyones situation is different, if you want the spring go get it! I'm not saying you can't! It certainly wont hurt anything, like I've expressed before, just don't like to see people spending money on parts they don't need. In your case it may be smarter to just get it now.