fgrdods

Can anyone share symptoms of a lift pump going out? I have had a few weird occurances. They are intermittent. The first time (This past weekend) I was merging onto the highway and coming up to speed (not thrashing it). TST was on 3/2. At about 45-50 mph, the truck started bucking and shuttering and the RPMs were very erratic. Felt like the truck was trying to run away. (?) Don't know how else to explain it. I had a foot full of brakes and the truck was trying to go. Not a good feeling!!!! When I made it to the shoulder and put it into neutral the RPMs spiked again, so I shut it off. Everything happened sooo fast, but I didn't see any smoke. The truck would turn over and try to start, but would not stay running. NO CODES.... (?)
I sat there for a few minutes and tried again. The truck started up and acted fine the rest of the day. That night, I stopped to get fuel and the truck wouldn't start again. It tried to start, but wouldn't stay running. Like it wasn't getting fuel. I bled the filter and found a connector (I think to the MAP) that was loose. Messed around with all the connectors and the truck started right up and I haven't had a problem until last night.
Last night, I was pulling into a parking lot and it started acting up again. Checked all the connectors and didn't find anything unusual. It started right up and haven't had it happen again, yet... I am getting a fuel pressure gauge, but don't have any data for that yet. I guess a question would be, can the fuel pump act like that intermittently or is it normally all or nothing? I am trying to eliminate the TST and EZ. The EZ is off the truck and the TST will come off tomorrow. Any thoughts??? Thanks.