When you are on a pump and blood sugar goes high, like over 250 you should give yourself an injection. Check your blood sugar regularly and if it's still high, you might be sick or getting sick or something else going on.
Once you give yourself an injection, change out the infusion site, tubing, reservoir and open a new vial of insulin. Change it all and then check blood sugars until you know you are getting insulin.
My blood sugar goes high quite regularly because I take blood thinners and the canula gets occluded. A few times I dropped the pump and the canula pulled out a little and blood sugar went high. usually though this happens after i changed the infusion set and the blood is in the canula. I just call medtronic and the replace the infusion sets without a problem.