454 hesitation and stuttering...

[06scooby]

Hey I just got the k3500 back from the tranny shop today and now with that out of the way I can focus on the other few small things in the truck. Boy let me say that tranny shifts with some aggression now! Here's the current issue, i'm getting some hesitation and stuttering under load. Very randomly when I get on the gas going up hill, the motor will cutout for just a split second with a pop sound (kind of like a backfire but nowhere near as loud or violent) and when I'm up on the freeway I get some alternating hesitation and surging especially above 60. the engine is warmed up when this happens. The tranny guy suggested to me to change the fuel filter after driving it which probably won't hurt. also the fuel in the tank has to be over a year old seeing as how the truck sat a lot! Since there was less than a 1/4 tank of gas, on the way back to work earlier I put a good 15 gallons of Chevron Premium with some fuel system cleaner in it and the fuel filter will be changed later. Hopefully this will clean things out a bit. Does this sound like common symptoms of just a clogged fuel filter? or something more major? any ideas?

 

thanks,

 

dp

[95Sierra2500]

It sounds like you're getting a misfire condition, I would suggest cap/rotor/plugs/wires.

[06scooby]

well I changed the fuel filter when I changed the oil and it didn't make a difference at first... there was definitely some power freed up after it was changed but it was still hesitating. I got home (barely) and let it run for a few minutes. I was getting some random clicking on the passenger side bank of cylinders and the engine was surging at idle (what could that be?). I took the air cleaner off and sprayed a good amount of air intake cleaner in the throttle body and revved up the engine. After all that It seemed to smooth out a little bit. so then I thought I would drive around with the window down and listen for that "pop" noise when it stuttered. Now there is no hesitation. I don't know if I just finally worked all the old gas out or what. Now (other than some slight random reduction in power) it runs pretty good. Not sure what but I drove it around for a good 25 minutes flat out flooring it a few times and it seems to be doing much better!!! I'll drive it again tomorrow and see how it does. I'll keep you posted, but any suggestions are still accepted. I think this weekend I'm going to give it a little tune up and check the timing.

 

dp