so i ordered new spark plugs, i am trying to get to the bottom of weird stuff with my truck. the truck idles rougher, but after a munite or 2 sitting at a light, it starts randomly doing really rough idle, it is not constant, just totally random, like someone hit the truck with a sledge hammer, or the gas didn't burn fully in one cyclinder, and it seems to be realated to some tranny problems i have been having.

i have a post in the tranny section, my second post explaines it what has been happening.
tranny troubles

 

don't everyone answer at once

 

anyone

 

not throwing any codes?

 

Original parts right? My bro ran into a lady that worked for GM. She told him even tho GM says plugs last 100k miles, they're finding more on the order of changing them @ 50k-75k. I just changed his original plugs w/85k mi. I found center electrodes bout gone, excessively large gaps, & generally pig rich, particularly if it's a factory tune. He said his mileage improved now. I would do plugs for that alone. Just my .02. I also read your other post. I'm no mech., but w/ gas so $$$, I pay attn. to stuff like plugs, wires, & o2s, even tire press. Nowadays, that's all a tuneup consists of. Check on scanner or HPT to look for codes. Last thing ya wanna do, is start throwing $ at trans, fuel system, or whatever w/o finding actual problem.

 

I don't really know for sure, but I would check and possibly clean your MAF. I am starting to have some tranny problems and my truck also does some random little shakes when idling (doesn't sound nearly as bad as your "sledgehammer" though, lol), and the transmission place said their book pointed to the MAF for the tranny problems somehow. When they checked it it had oil on it somehow (K&N filter maybe? But it shouldn't have been over-oiled since it was stock). Either way, I could see a MAF causing some idling problems if it isn't reading consistently cause it's dirty. I don't really know though. Just a thought.

 

check for a vacuum leak or check the plug wires..also check your plugs to make sure the are not cracked or dinged anywhere. i had a plug that was cracked and it made my truck run like crap..

 

yeah i am not trowing any codes, and it only does it when sitting for a minute or two, then i just feels like it has no power. I ordered the tr55-IX, should i just leave them gapped at .05? i'll go ahead and clean the maf see if that changes anything. I was riging in my friends 99 454 suburban yesterday and noticed his kind of did the same thing, at least the random rough idle, but not the tranny issue. I just think they are interrelated, if i make a quick stop, i don't have any problems, but if i am sitting at a light or in traffic, i start having issues.