Engine Hesitation?

Once in a while when im on the highway and try to accelerate my truck slows down and I have to floor it for it even to pick up the speed again, and after a couple of seconds I let go of the gas and press the gas and its good again. For some reason it also wont go past 70 something mph. I know its not the transmission, or fuel pump. What do you think is wrong with it?

I will try it in the morning, but I don't think its had to do with the catalytic converter or fluid pressure. I am going to try it and let you know what happens.

Hi I recently bought a 1993 silverado 4wd from a friend I noticed that sometimes driving at normal speeds anywhere from 25 to 55 that sometimes when I floor it to pass someone the truck starts to go but doesn't have very much power like its hesitating then a few seconds later still having it floored it will jerk and take off and have PLENTY of power. The transmission doesn't slip or anything but it does bang going into second gear. It also hesitates sometimes when taking off from a stop but only if I give it alot of gas it will do the same thing. It will hesitate for a few seconds and then take off with plenty of power. The last thing is when im going very slow 5-15mph and barley have my foot on the gas it will kinda of jump up and down like its gonna die but if I give it more gas it will go back to normal. Any help would be great thanks!

I have same truck and it does that too. However not so extreme when idling. But it wont shift into overdrive and when accelerating from a stop it is sluggish and wont downshift or hit passing gear when flooring it.

1993 Silverado K1500 5.7L.
Engine runs fine at all RPM's in park. While driving though it stumbles and sputters bad when I put my foot in it. It will shift fine in D4 or manually shifting lever, as long as I don't push the accelerator too hard. Check engine light is on, but it's been on for 6 years or more. I can get up to normal speed, just takes longer. Doesn't seem to be clutch slipping. Gas mileage dropped also when this started.

Code was 32. Didnt' check fuel pressure, but one clue might be in Park I can rev the engine up all the way without running bad.

Cleaned out the EGR valve. Replaced cap and rotor. Engine light went out. Runs great in park. In gear it still cuts out when applying more than light/slow pressure to the pedal. When I get up to speed finally (45), on a warm day, I punched it and XMSN slipped but RPM went higher and smooth instead of cutting out. So it seems the XMSN is slipping. But the cutting out off idle in gear seems more like ignition/fuel/sensor. It's TBI and doesn't have vacuum line on fuel Press Reg or valve port on fuel line, so don't know how to check regulator or fuel pressure.

My truck keeps stumbling. I have had the gas tank change it was rusted and a new fuel pump and filter. I also changed the throttle body. I am leaning towards the new throttle body. When I start moving it starts stumbling and at low speeds it does it. When I put it in park and rev the engine the rpm's go up and then falls low and acts like it is going to die. When I park it and turn the wheel it dies. Any suggestions? I also ran sea foam and that did not work. The motor is brand new and I had the timing check it was right on. Thanks.

Ok I did all that rpms did not go up I can't ad smoke since I don't have a machine I notice that I have a leak in the hose going to the fuel tank. It's the line that goes from the back of the fuel filter into the tank. It is leaking in that rubber fuel line part. It only leaks when the pump is turned on. It is a small leak.

So a while ago I asked a question about my truck (K1500). It was stumbling when I hit the gas and was acting weird had fuel pump and fuel tank replaced also the throttle body replaced almost at the same time. So I was not happy with the throttle body everybody I kept taking it to kept saying it was a fuel issue so I had put a can of pb blaster out my dad thought it was carburetor cleaner and sprayed it with the truck on. It runs so much better no stumbling or anything. Could this be a throttle body problem? After he sprayed it I got an EGR code I just changed it. After he sprayed it the code set. The only problem I have is if I am sitting it acts like it wants to shut off but does not. Thanks

My truck hesitates on acceleration, but gets a little better when it gets to 160*. When first started the idle fluctuates up and down. Items i've replaced, map sensor, idle air control valve, throttle position sensor, egr valve, fuel filter, fuel injectors and connectors, distributor, ignition control modual, timing chain, tempeture sensor, ecm, plugs, wires, cap and rotor.I have no codes to be read. And after 100's of dollars I still have the same problem as when I started.