2000 Sierra 1500

[sanders06]

Hello everyone, I am new here so hang on tight, I will try my best to describe what happened... I drive a 2000 GMC sierra 1500 5.3L, which until 3 days ago was working perfectly... I filled her up with a full tank Thursday evening and managed to drive oh lets say a good 3 blocks, pushed my auto 4 Wheel button so I wouldn't sit there and spin at the stop light, thats when everything went bad... The second I gave it some gas to get going, I immediately lost power and the engine just started to die. In all of my wisdom I decided to just hammer the pedal a little bit and everything kicked back in fine and dandy. I got home and shut it off only to have to leave a few minutes later, went out to start my truck, it fired right up like a champ, but only ran for a few seconds then died. I tried again this time giving it some gas as it started to die out and it just slowly died anyways no matter how much throttle I pushed it at.

This leads me to today, that night I called my pops who was a mechanic for Fords (Sad I know, he drives a GM now) for a solid 22 years.. My initial thoughts were my fuel pump went bad as I had heard reports of them dieing after about 140-150k miles. My dad shot that down, as he put it.. "In all my years of working with vehicles, if a pump failed it just never started, it wouldn't start, run for a bit, then stall". We thought maybe we had some water in the fuel lines so we dropped in a bottle of isoheat and let it sit in the shop (heated to 70) overnight in an attempt to let it maybe thaw a bit if it froze anywhere. Went out to the shop the next day at lunch, truck fired up, ran for a solid 5 minutes, then killed and would not start again no matter what. My dad sprayed some ether in the intake to get it to fire, and the only way it would stay running is if he continued to spray the ether in, which then led him to finally believe the pump either went out or the filter is probably plugged. I went to the nearest carquest and ordered a new pump with overnight delivery and picked up a fuel filter and went ahead and changed it, still didn't start.

Yesterday when the pumped arrived we went out to the shop, took the box of the truck and changed the fuel pump hoping all my problems would be solved and I could stop driving my impala that I am trying to sell. I got in the truck, turned the key over to ON so the pump would kick in for a few seconds... But the pump never kicked in, my dad thought maybe he was just deaf so he held his hand over the pump while I once again turned the key over, and it did not kick in. The next step we went.. we replaced the fuel pump relay and checked EVERY fuse labeled as having anything to do with fuel system and they were all good, truck still would not start, turned over like it wanted to start, but wasn't getting any fuel. Logically I assumed the fuel pump we got was bad, so my dad pulled his truck into the shop, disconnected his lines from his pump and connected my pump to his lines, and the pump worked when he turned his key over. Ohm meter says there is power where my fuel pump relay is so now I am at a lose of what could be wrong as to why there is no fuel being delivered? Any help on the matter will be greatly appreciate as I don't want to tow it to our local dealer and pay an arm and a leg for them to scan it. We did scan the service engine light ourselfs and it pulled a p0102 code, which is low voltage to MAF sensor, pulled the MAF cleaned it off, put it back in, service engine light went off and no codes being displayed now.

One last thing, for giggles we decided to check if maybe it was still in auto 4 wheel and to take it out, but, the kicker is it won't light up ANY of the drive options, nor will it let me switch them.. anyone have any ideas on what happened?

[sanders06]

Tried to edit typos and it nerfed my nicely paragraphed post Sorry guys

[MYZ-71]

try checking the tbc 10amp fuse under hood, just a guess.

[sanders06]

Checked it, it was good

[txab]

Have you checked for full voltage at the fuel tank connection?

[sanders06]

Checking voltage tomorrow, never had time to get out to the shop today. Off the top of you head as I can't reach my dad currently, is it suppose to be a full 12V going back there? Local GM Tech said the same thing, that there is probably no power to the pump.

[cwendel4]

Check your fuel pressure regulator.

 

A fuel pump that is bad would never have let you gun it and get the truck moving. A bad or clogged rulator will not let fuel in to start the truck.

 

Second, when changing the pump, make sure you did the change tot he wiring that is needed. Also, make sure that the fuel gauge works. If it is not and reads empty, the truck will not start because the pump will not run since there is no fuel to pump according to the gauge and to keep it from overheating due to no fuel to cool it.

[doubled1]

Have same truck with similar problem that turned out to be a short in the wiring that was causing the truck to die on the hwy.The wires eventually burned off and truck wouldnt start.New fuel pump and still no go.The mechanic started checking the wiring and said he found problem where the wires had rubbed on the body and shorted.He said it was around the computer but not sure exactly where he meant.I do know that it wasnt the fuel pump.