My Truck Is Bogging And Hesitating Under 2000 Rpm's. It Only Does It Sometimes. I Took It To A Dealership, And They Said It Was A Bad Fuel Pump, So I Put A New One In It And Did A Complete Fuel System Flush. I Dont Know What Else It Could Be. The Truck Is A Stock '00 Model 5.3l With Intake Longubes & Exhaust. Oh Yeah, I Pulled The Plugs Out And They Are Really White, Looks Like It Is Runnin Too Lean. Any Help Or Suggestions?

 

Sounds like you have an air leak in the intake manifold area to me. The white plugs are showing a lean condition. Get a can of starter fluid and spray it around the gaps and joints of the intake. If the RPM speeds up, you found your leak.
One other thing, check the IAS ( idle air solenoid ) circuit. If it is stuck open it will do what you are talking about.
I had the EGR tube from the valve to the intake tract crack and also cause the same symptoms you are seeing. Can't see the tube with the heat wrap around it, once it broke completely in two I found it. It happened after installing some headers, we did not attach the one bolt that holds the valve assembly to the head and vibration cracked it within 4 months. My bad....

 

I saw in another post you have a maf, and throtle body. If you have the bbk throtle body, your gonna need a good gasket for it (not the thin rubber one thats stock), there notorious for leaking, also if you have the granelli maf, ditch it for a stock one.

 

Definately get rid of any aftermarket MAF sensor. Been there - Done that -Nothing but a waste of money. They are too hard to tune correctly without tricking the computer. Also try cleaning the MAF sensor. I get the electronics cleaner aerosol spray at autozone. Works great, really helps. When I drive my truck alot in the rain the moisure in the air soaks into my K & N cold air intake. The oil from the filter get coated around the wire sensors in the MAF. My truck does this all the time. The electronic parts cleaner works every time for me. Good luck!

 

Well I Got The Maf For Free-traded My Stock One, So I Cant Go Back There. Next On My List Was Air Leaks, Would An Intake Gasket Cause This Also? Could It Possibly Be A Fuel Problem? IAS? WHERE THE HELL IS THAT?!

 

IAS (Intake Air Sensor) is located in the MAF sensor

 

Good Luck

 

Sorry I forgot my names. It is the Idle Air Solenoid and is located inside the TB at the very top. Don't push on the black plunger when cleaning, it can mess it up.

 

i found a cracked tube last night. i dont know what it goes to. it is like a 3/8 inch plastic hardline. it comes out of the top of the intake manifold in the front, comes down the driver side, right behind the alternator and makes a 90 degree turn and goes straight back towards the firewall right above the fuel rail. it has a service port on the side about halfway down with a little green tag on it. what the hell does that go to? anyone? could that be one of the problems?

 

A vaccume into the fire wall might go to the HVAC controls, if it has a hole in it fix it and go from there.