Question
I have a 98 tahoe lt 5.7 4+4 I bought it 2 yrs ago it has about 108.000 miles on it. Anyways it had a real loud fuel pump on it when I bought it so I drove it for about a yr and decided to change it before it went. So we got one and put it in about 3 or 4 months later it wouldnt start and I noticed I couldnt hear the fuel pump running checked all the fuses but it was low on gas so we firgured it was frozen due to the winter weather so we towed it to my fathers shop it sat for a day but that day was warm so we tryed it before we did anything and it started so we came to think it was frozen fuel line so while we had it there we put a new filter on it witch was full of grud. But we also noticed that the fuel pump would run after you shut the truck off my father never heard of the fuel pump running after the truck was off and I asked around and other people had never heard of that ethier.
When it runs after I shut it off some times it runs for 4 or 5 seconds and some time 10 seconds.But it ran. so about 3 weeks later it wouldnt start again but now I had a full tank of gas same thing couldnt hear the fuel pump run so we tow it back to my fathers and put another fuel pump in it and it runs. But we still hear the fuel pump running after we shut the truck off. I drove it home and it ran real rough for like 10 minutes then I didnt have a promblem untill the next day I started it and it ran like [censored] for anout 2 or 3 minutes then it was fine I drove to work it sat at work over night drove it home ran in the house for about 10 minutes came out and the same thing it wont start. So after that long story about it my questin is have you heard of this problem in theses trucks or motors and should that pump be running after the truck is off we dont know if it has a regulater or where it would be on the truck or if that would have anthing to do with it.the truck fires but wont start. Please help we are out of clues. Thank you

yes it has a fuel pressure regulator,it is inside the upper intake plenum,it was notorious for leaking down and causing a long cranking time to get truck started,you have to have a special setup to check to see if it is leaking,basically you pull the fuel filter and put a tee in line where the filter goe's so you can check both sides to see if it is the fuel pump leaking down are if the fuel pressure regulator is leaking.most likely from your decsription of the problem i would bet it is leaking,because it dumps raw fuel into the upper plenum.

There is a problem of some kind with the wiring harness connection, the ground lead has been faulty for some. Heard today the AC Delco replacement pump comes with a replacement plug. Had another tow truck driver tell me he jumpered the ground lead across that after market harness plug and made his sporadic running issue go away. However, I did not hear him say his pump continued to run after the ignition was off, I do not think mine has done that. Are you sure it isn't your AC lines equalizing out after the shutdown?

From what I heard today from a GM Master mechanic and my issues related in the link below we are crazy if we use other than AC Delco replacement pumps.

I have a 97 GMC Yukon (same as a 97 Tahoe) the pressure regulator valve leaked. On a 97 the upper plenum opening and closing job to get to that $90 valve is about $700 labor and new seals. Half the upper engine hardware is mounted off that plenum. I got about 210K before mine was detected as leaking, but not seriously. However it has to be a potential fire fuel producer, so it needs to get fixed if you have a leaker.

Related issue from me.

look in you fuse panel in the truck my 99 z71 did the same stuff and i did the same you did and it was a blown fuse

note: if you can hear the fuel pump in a chevy it IS going to go out

I blew 4 fuses total. Come to find out a wire insulation between the fuse block and the pump grounded out on the heet metal. Call Rick Radiator 972-723-8467 in Cedar Hill they can describe where they found the wire grounding out.