1998 Silverado Bogs Down

[7sam7]

I love my truck! But it just began having a problem. Here's what it does -

 

1) If it starts at all, it starts hard.

2) Spray a little gum cutter in the air intake and it starts immediately.

3) Idles forever. Smooth.

4) While in park you can rev it up. Over and over. Seems smooth.

5) Most times, it will go when you put it in drive but begins to bog down when you get to around 1500rpm. Spits & Sputters. Will even stall out if you keep throttle pressure.

6) Some times, it will stall out as soon as you put it in drive. Keep it in park and you can rev and run.

 

Note - I just had a new fuel pump installed a month ago.

 

And ideas on the cause?

How can I test them?

 

Thanks for any help you have!

[BigJayDogg3]

What engime does it have?

[7sam7]

What engime does it have?

 

 

350 (5.3) Vortec

4WD

Auto