You can listen to the injector with a stethoscope or even just a wooden dowel rod. Press your knuckle on the end of the rod and then press that little cartilage flap on your ear closed. Put the other end on the injector. You should hear it clicking. If it isn't, or sounds different, that's where you look. As for a rebuild for $1600, that is awful cheap. Recent ones I've been involved with ran from $2800 to $3500.

Don't go throwing money at the truck until you know what it needs. As for the thermometer, invest in one. You can get decent ones for under $50 at Harbor Freight. Besides misfires, you can check thermostats and so on. It will sometimes paay for itself the first time you track a puzzling issue down.

 

im 100 miles from any town / city that has stuff ,,,,,,,,so driving to one for parts aint gunna happen as much as i love harbor freight stuff.....im at min 2 hr drive from one. ill try the tube thing i have a clear tube someplace....
most everything i get is by ups or fedex some by us mail.. have to remember when i go see docs in the big city to swing by harbor freight if there close .....

 

I'm similarly geographically-challenged. Our Canadian HF (princess auto) is happy to do mail order and it comes pretty quick. Actually, most anything I can't get off-the-shelf at my local hardware store or tiny auto parts store, I order online.

 

I'm fortunate that I'm in a big small town. Big enough that anything I might need is nearby but still a small town. Plus, I never throw anything away in case of future need. I'm also chea...er...thrifty and if I don't have it might be able to make do without. (i.e. wooden rod in place of a stethoscope)