so ive been havin a problem with my 01 silvy boggin out on me the past few weeks...during daily driving shell randomly bogg out on me or on the 1-2 at part throttle...also the truck at WOT will either run like a bat out of hell or like a damn turd...n it just randomly goes back n fourth...i was thinkin itd most likely be the fuel filter n i havnt gotten around to that yet...i just did the plugs yesterday afternoon and when shes cold she has a little miss at about 1k-1800 but goes away after shes warm...i think my problem is my plug wires...yesterday while trying to pull the wire i slid off and yanked the wire straight from the boot. i fixed it temporarily since im a full time student and since i have to wait for summit to send me the taylors but shes just running like garbage.. after i installed the new plugs yesterday i took it for a test drive n she legitley cut out on me at 5k...havnt punched it since, im gonna wait till i get the new wires n install the new filter n see what happens. if this doesnt fix it what else can be wrong? it never had a misfire before just a bogg. now it has both

if anyone can help me itd be greatly appreciated. btw the truck is a 4.8, mods in sig, and i just installed E3's. not to mention right now it feels like im running on 6or7cyl

 

Check your fuel pressure, could be your pump goin out. Mine did all that you mentioned right before it took a dump on me.

 

damn this is shitty lol, ive always heard bout gm pumps shittin out at 120k'ish. how do i find out my fuel pressure? autotap type deal? also would it hurt to run a higher volume pump with my mild *** mods for the time being? its goin procharged later on in its life...id rather just replace it with a high volume one so im not doin the work n spendin the money twice ya know? btw fast thanks for the input i really appreciate it...also i thought elec fuel pumps either work or dont?

 

bump, no one can help me out here?

 

There is a 1/4" fitting on your fuel rail with a shrader in it. You will need either a fuel pressure test gauge kit, or you will have to make your own. A refrigeration hose works to go on the fitting, and they have depressors to open the shrader. You will need a 0-100 psi gauge, and fittings to adapt it to the hose. Then tape the gauge to the outside of your windshield, and go for a test drive.

 

what should my pressure be during this test? i just did my fuel filter and the truck runs alot smoother and so much stronger...still got a little hesitation but barely noticeable...wont cut out at high revs either anymore. n thanks for the help mikegyver where ya from in northern il if ya dont mind me askin

 

The pressure should be 62 psi, I'm pretty sure, when the pump runs with the engine off. Turn the key on to "run", the pump should run for two seconds, and the pressure should go up to about 62. When you are cruising, pressure should be about 55 psi. At full throttle, it should go back to about 62.
I'm about as far straight south of Chicago as you are north.

 

thanks for the help n gotcha man. as for the pump i forgot to note this thing whines like a ****...im sure from retards not changin the fuel filter as often as they should causing premature failure...then again this thing has always had a nice whine to it. n hopefully ill get the chance to see where that fuel pressures sittin at startup daily n wot...can i run a high volume pump (future procharging) so i dont have to tear my fuel pump out of the truck again? id rather just do this once instead of twice ya know

 

anyone?

 

I'm an Automotive Engineer from Detroit area... I worked with Fuel Systems and Fuel Pumps 15 years ago. The basic workings are the same today.

Your Fuel Pump is within a cannister. The sender is attached to the cannister. The assembly is called a Fuel Module. The Module is submerged within the fuel tank. Gasoline liquid is a dielectric and does not conduct electricity nor does it burn. When the fuel vapers mix with air, it burns. The module helps reduce sloshing effect within the Fuel tank during turns acceleration and deceleration. The pump fills the module and pressurizes the system. The pressurized system is fuel lines, the fuel rail and the fuel injectors.

Regardless of vehicle make, all fuel pumps are made by a limited number of fuel pump suppliers. Pump elements on the electric motor differ due to the required output. The electric motor in the pump is required to last @ 100,000 mi; the pump motor does not have brush thickness to last forever. 120,000 mi is a good time to be alert.

Pick ups have higher output requirements than most passenger vehicle and in your vehicle's case, it puts out a high pitch whine. That's normal. That's the pump rotating and not a defect.

One sign of a weak pump, there's a reprime stage when you start your vehicle. From OFF, turn the IGN without starting. You should hear that whine. That's a 5 s reprime designed for the pump to pressurize the system. If the pump is weak, you may have long starts. If the vehicle is cold, sometimes a weak pump may require multiple reprimes. Reprime the vehicle a few times before cranking the engine if in a pinch. That is turn the key on 5s then off a couple times. Listen for the whine.

Also, another sign is hesitation in acceleration, higher speeds or loss of power on hills. Sometimes you think your transmission is mis-shifting. Its the pump not keeping up with demand.

Aftermarket parts don't have any of the requirements that Original equipment has. They are always inferior. Going with a higher output aftermarket pump won't help you. The system is designed for a specific output and may conflict with the fuel rail or injectors.

You will either have to remove the box, drop the tank or cut a 18X18 access panel in the bed of the truck. Since I worked in that commodity years ago, I always cut the panel so I can do the repair on the road. I keep a spare module in the vehicle beginning 120k miles. If you are unprepared, when the pump finally goes, you will need to be towed. The repairs will include extra for fuel capture during repair etc... Whether you do it yourself or farm it out, make double sure the vacuum lines and filler tubes are attached securely. Some vehicles will stall when vacuum lines are insecure. The fuel filler needs that 2nd smaller tube in parallel to shut off the nozzle at the filling station. The repairman always seems to miss something.


I hope you can understand my writing. I'm not in an editing mood today to check for grammar, poor composition or completeness.