[astreamk1]

I would start by checking the fuel pump fuse. When the pump on my 90 gave up, it started blowing the fuse. I would replace it, would run for a while, and it would blow and quit again. It is in the main fuse box under the dash.

The pump is not hard to replace (if that is what is bad) . It is under the back seat and can be changed in about 1/2 hour. The pump itself is not cheap though. I am gonna guess your going to pay around $200 depending on where you buy and if you get just the pump or the whole assembly.

 

[astreamk1]

You don't think there is any way they could have monkey'd something up while they were working on it ? Did you check all of you fuses ? I would make sure they didn't accidently short something out and pop a fuse in the fuse box or out under the hood. I am always leary when someone else touches my car. I do not know if the ECU has anything to do with the fuel pump or if it basically just works on pressure ?

If the pump just did up and die, I wouldn't think the garage labor would be very much. I can't imagine it taking an hour for a mechanic who has never even seen a Sentra.

 

[astreamk1]

I looked it up in the FSM last night, and there is a very easy test for figuring out if there is power and ground present at the fuel pump. I do not have a scanner, maybe someone here that does can scan the 2 pages for you if you don't have the FSM. At least you'd know if the problem is in the wiring or the pump itself. I'd definitely check it out before I dropped the money on a new pump. Esp. being you had someone cutting into your wiring.