ive noticed it making a lot of noise when it charges up, its been whining on and off since i bought it. its been hesitating at full throttle for a while now, i chalked that up to plugs and i was going to mess with it later. well i was on my way into town the other day, had the cruise set.... then it felt like i hit a brick wall, like i had run slam out of gas. which i know i hadnt because i had just put in 30 bucks(which isnt **** anymore).it just starts sputtering after that, i take it to the slow lane and it **** all over itself until i got it off the freeway.once on the feeder i punched it, it dropped down into first and wouldnt go anywhere, just bogged down really bad. got to my destination, was there for an hour. go out and start it up, kinda sounded shitty, and it was evident right away that something was wrong when i put it unto gear. i barely made it out of the parking lot. had to manually shift it to get it up to speed, sputtering and farting all the way. i limp it onto the freeway to try and make it home, it barely got up to speed. but once up to speed it faired well all the way home.once there i did a couple 60mph full throttle runs,on the back road, the hesitation was still there, but it didnt just competely bog down. feels really low on power. im changing the fuel filter first, of course. but what do you guys think, fuel pump maybe? any suggestions would be appreciated. off topic side note: im having to drive my beater grand marquis... im so surprised that thing still runs.

 

look guys, ive used the search function, for you sticklers. it wouldnt even come back with a result for fuel pump. so could at least one of you muster up enough consideration to at least suggest something, id appreciate it. replacing the fuel filter tomorrow.

thanks

 

What kind of vehicle?

 

99 silverado stepside, 4.8,automatic

 

mods are: pulleys, old style volant, and dual exhaust, no cats, the sites most hated mufflers.

 

You've got to put a fuel pressure gauge on the schrader valve on the fuel rail. The pressure has to be very close to the spec. The range is 55 to 62lb. If you're below 55 you're due for a pump change especially with your symptoms.

 

You very possibly have a fuel pump going down. When they start squeeling a high pitch whenever you start them, is always a bad sign. GM dosen't really have the noteriaty for having a reliable long lasting pump either. I sell Fuel Pump Modules here at least 2 to 3 a week. They are however more president on the 2500 HD vehicles, but most of those I sell oare offroad work trucks. I rpleaced the the fuel pump module twice in my old 2003 GMC 5.3.

Get you Fuel Pressure Guage (relatively inexpensive) hook it up to your fuel rail and tape the gusge to your windshield where you can see it clearly. Monitor the fuel pressure at start up and as your driving it. You should push 65 lbs of pressure but as low as 55 in in tolerance. But if you drop under that......yep....you should consider buying a new Fuel Pump Module.

 

I dunno....every time I've seen a fuel pump go the engine will either shut off while driving or won't start after sitting for a little while. Definitely get a pressure gauge on there though, that will tell you for sure.

 

belated thanks on your replies, guys. filter replaced, dont think it made a difference. it still is way underpowered. ive got a set of copper plugs in there that i know i need to replace, thats another deal.i dont think the plugs would have caused that sudden loss of power i experienced on the freeway, and it bogging down so badly. i need to get a fuel pressure gauge, and go from there.

 

Indeed do the Fuel Pressure Guage....that's the only way you're going to diagnose this.