jeffs_62

We have a 2002 Suburban 1500 4WD. 5.3 MPFI gas, not flex fuel.

We have had this vehicle for seven years, and use it on a daily basis, and we do all our own maintenance on it,so we know it pretty well.

Maybe a little detailed, but the rules said to be as specific as I can.

Yesterday we had something happen that has us dumbfounded.

We were on our way to the big city about an hour away, and half way there it seemed to fall on it's nose climbing a light grade. back off the throttle, and it picked back up, but wouldn't accelerate more than slightly, if at all. concerned, we pulled over to inspect it.
First thing I did was rev it by hand at the throttle body, and it will only rev to 3000-3500, and starts running rough and falling on sputtering. Next, I looked at the wire to the Throttle Position Sensor, clean it and put it back on, next looked at the vacuum line to the Fuel Pressure Regulator. Neither seemed to have any obvious issues. Clean, sealed, and no leaks. However, truck started revved and acted fine.
For a while.
About fifteen miles later it does the same thing. We ran our pocket scan tool, and got no codes. We decided to head home. 30 miles later it dies.
I again mes with the Fuel Pressure Regulator, and it starts and runs fine for 15 miles before it does it again, and we limp it home.
At this point, I am pretty convinced that I need a new Fuel Pressure Regulator.
To be thorough, I replace the TPS, and FPR. No improvement. After reserching my issue on this site, I came to think possibly fuel filter, and possibly fuel filler cap.
None of this has cured my issue, so I thought I would ask for help, before I get too far into it.

I would appreciate any and all input from you guys/girls.

notagain

Check fuel pressure at the rail while under acceleration had this same problem with a 4.3 put new fuel pump in and been running perfect for over a year now knock on wood.

On my 99 suburban acted a little like that it turned out to just be a dirty mass air flow sensor. Good luck

cleveland63b

i wouldnt replace anything until you hook a fuel pressure gauge up, gm fuel pumps are pretty common weak points

jeffs_62

Took it to Pro Tech and put it on their scope. Turned out to be the fuel pump and sending unit. Good news. It's all better. Bad news. These fuel pumps are expensive.

jeffs_62

Thank you for your input.