i've been having this problem with my 5.9L lately. before it was only sluggish in the rain or wet environment. it eventually got bad enough to where it was doing it all the time. my foot would be to the ground, but the truck would just lose power and then i would give it a little gas and it would go like a bat outta hell. does it all the time. almost stalls when i come to a stop as well. well i thought i fixed it a couple days ago by installing a new ignition coil. i've installed all new dist. cap, rotor button, and wires as well. and it ran good for about 2 days, then today, it started again. i'm getting so p**sed off that i'm about ready to get a new truck. someone please help!

 

several guesses.
sluggish throttle and stalling can be caused by TPS. drivers side of throttle body, about $40-50 at local parts store.

clogged cat can prevent the engine from reving up to higher rpm's, but its usually a little more consistent than what you are describing.

more guessing, but have you checked your fuel pressure. need to do that. you could have weak fuel pump or clogged fuel filter (in tank).

might have water in gas. if you haven't already done so, pour a bottle of fuel treatment in the tank. look for one that says it treats for water.

interesting about running good for 2 days after new wires. does it feel like its missing or skipping? wrap your wires in plastic wire loom (or rubber hose) to keep them from touching anything and see if that helps.

what is your local weather ? is it back to raining, like where you had your original problem. if so, get a tube of di-electric grease. remove every electrical connector you can find, and apply a little dab of grease. not much, just a dab, and reconnect it. it will keep water and corrosion out.

 

you know,

a bad battery can cause funky issues like that. it could be the problem as the battery is pulled on harder from a dead stop until you get the alternator going to take over the ignition load.

get your battery tested.

 

Are you saying it only happens when it is wet out? It's a little hard following when it is actually happening.
If it ONLY happens when it is wet out, I'd start looking for a loose connection or wire under the truck, maybe the O2 sensor.

 

well, it USED to happen when it was only wet out. now it's happening all the time regardless. i'm pretty sure i dont have water in my gas and my fuel pump/filter was changed probably about 6 months ago. it doesnt skip or miss at all. it won't idle anymore and when it does decide to idle, it idles like crap. it sucks getting stuck in traffic and having to shift to neutral every two seconds to rev the engine to keep it from stalling. i'm gonna go test my battery out. be back in a bit with an update

 

Sounds like an IAC problem to me.

 

in fighting an idle problem, if you can lay your foot on the gas pedal slightly and keep it running, and there are no other obvious cel's or skipping problems, then i'd replace the TPS and IAC, one at a time. i'd remove IAC first, and check that the port into the TB is clean and not gunked up. if dirty, clean and reinstall. if reasonably clean, then replace it. don't push, pull, or twist on the pintle. it'll break it. reset pcm after any changes.

 

what an IAC? also thought i might throw this out there. could make the difference between whats the problem is and isn't. i get a check engine light sometimes. it decides on it own when it wants to come on. anyway, i checked the lights and it gave me code 21, which is 02 sensor. as far as i know, i dont have an 02 sensor, i have one egr port in the right hand exhaust header. can anyone please ellaborate for me? what im thinking is that since a long while ago i broke a bolt off of the exhaust header and have had no way or time to get it out and replace the bolts or headers, well what im thinking is that the air/fuel ratio is getting f*cked up and thats the reason its running like crap. idk. im at a loss. any other ideas?


oh btw, battery is perfectly healthy.

 

and i have no idea how to reset the pcm, or what the heck it is anyway

 

Yeah ya' do ... do you still have your cat? It's on the front side of that.