Every so often I don't have a hesitation but a hard 1-2 shift & sometimes a less hard 2-3 shift. Then if I stop or park it it will be OK. I'm guessing a solenoid or something. This truck has 160,000 hard miles on it. I have serviced the tranny & have a B&M superCooler on it.

 

I NEVER imagined this was the problem at all... the p0300 code really threw me off but...

I found my problem by accident today. After changing my coil and resetting the computer, i started the truck and my CEL was on, high as hell idle and wouldn't kick down. I took a look and seen my MAF wasn't plugge din and neither was the other plug on the air ducting. Plugged them both in, truck stalled out. Restarted and it stalled. Unplugged my MAF and it ran just fine. So now im going to get a new maf from AutoParts warehouse since they are cheap as hell compared to anywhere else. 68 or 67 compared to the $200+ from autozone or such.

 

My 03 has the hard shift as well. I was told to replace the 2 shifter modules in the tranny. Need to drop the filter so I am waiting for some $$ to do it

 

So to finalize this post (so it can be closed if needed) the things i did to fix my problem was:

Changed plugs, wire, cap, rotor (due to the p0300 random misfire code)
still got p0300 code
changed my ignition modual
still the code...
Changed oil and filter (it was bout due anyway)
Changed Fuel filter (long over due)
Cleaned MAF sensor 3 times

none of the aboved seemed to fix my problem, so like i said in the last post i found the maf sensor problem by accident. So I then called a buddy and had him bring his blazer (97) to my place and swapped MAF sensors. He just bought it (the maf sensor) not even a month ago. Using his sensor the truck did not hesitate or shift hard, bog down. It ran like brand new. The CEL did not come on (i didn't bother unplugging the battery like the book says to do. The light didn't turn on when i turned the truck on) and nothing was wrong. To further test this though, i am borrowing his maf until mine comes in the mail. So far i drove 75 miles with his and still have no problems, so im putting my money on that it was my maf that went bad.

what i don't understand though is why did it throw the p0300 code??? my old plugs, wires etc.. was still practically new, not even a year old. so i know they couldn't of gone bad yet. But its better to be safe then sorry i suppose. Plus it started with no problems so i know it wasn't anything to do with my ignition. So there you have it.. for those of you still having this problem, id look at your MAF sensor. Fromt his experiance it can easily be overlooked id suppose, especially if youre getting a random misfire code.

So I hope this helps some maybe even all of you having this problem.

If this turns out to be a double post I apologise, but according to the forum someone else posted after I did, yet their post did not show up on my side.

Case closed

 

i dont know why but my shifting has improved since i changed maf sensors. It will still shift semi-hard at first but i think thats cuz its cold and im usually stomping the gas since im pulling out in front of highway traffic. also is your check engine/service engne light on?? if it is, get the code and post it.

Youre shifting problem might just be a sensor or something electrical.

 

Well, I got mine fixed. Not sure which did the job, but when I changed my intake manifold gasket...I cleaned the intake well, the MAF, changed the coil, the plug wires, pulled and re installed the distributor (had no choice)... may have been a combo of it all.