hesitation or stuttering with load
 

Ive had my 2001 Blazer for about four years, currently its getting about 16.6mpg in city and highway. But if im on the highway and I go to switch lanes, I merge and if I press the gas pedal a little too hard it will not accelerate but stutter and hesitate. I have to release the gas pedal and reapply it slowly. I really have to baby this thing now. My distributor looks good, and Im not having any other symptoms. I dont think its a fuel issue. This is the 4.3L vortex with the spider assembly and I cant think of what else it could be. Any ideas?

Does anyone have the fuel pressure specs for my 2001 4wd blazer 4.3L? Im going to make sure the fuel pressure is good at the fuel rail.

Turn off the radio, a/c and anything else that makes noise. Open the windows and while you're sitting in your driveway, try shifting between drive and reverse. If you hear a "THUNK" from under the truck, you may have a bad universal joint. You might also have one siezing up, but you have to drop it to work it around to make sure of that.

The fuel test is: key on, engine off, psi should be between 55 and 60, let it sit for ten minutes and it should not have bleed down below 50