K2500 shifting problem
 

I have a 1994 K2500 that has sit for about 2 1/2 years now transmission won't change until high rpm and I let off throttle also when I try to go into passing gear it acts like it is in neutral. I have replaced filter and new fluid checked pan no metal shavings clean fluid a little brown but no burned smell changed a and b shift solenoids. No check engine light before or after the replacement parts. I went out yesterday pulled transmission fuse as a last resort truck is sluggish but didn't jump out of gear. Not sure where to go from here. Any help greatly appreciated

"transmission won't change until high rpm and I let off throttle"
- a bad tps will definitely cause this type of behavior, but you will usually have a CEL if it's bad. See if the bulb is good and test tps voltage.
IF your 2-4 band is out it will shift from 1st to 3rd skipping 2nd and it will shift ONLY when you take your foot off the gas, otherwise those rpms will keep on climbing.

"when I try to go into passing gear it acts like it is in neutral"
- If your 2-4 band is out, when it kicks down to second (passing gear) it will act this way, I've seen this alot in the 4l80e

I just went through these exact symptoms with a 97 sierra
But mine also broke the sunshell so I had no reverse either.
That tranny was wasted

So when I pull transmission fuse it has no issue starts off in 3rd I think could it possibly be a stuck valve in valve body ? CEL Bulb is good haven't got to tps yet.

If and when you pull the transmission fuse, the transmission should go into what is called "limp home mode".
I have heard stories about guys having these types of problems due to a bad Ignition Switch (you might want to test that just to be safe) but the symptoms you describe just sound too familiar.

My money is still on the 2-4 band being shot.

Try this: put the transmission fuse back in
Drive the truck as you normally would but this time count the shifts.
Be sure give light throttle, don't be heavy on the gas.

Normally it would go
Start off in 1st at 0mph
Shift to 2nd around 15-20mph
Shift to 3rd around 30-35mph
Shift to 4th around 40mph
OD at around 45mph

If you count any less than 5 shifts, you're more than likely shifting straight from 1st to 3rd skipping second.

Here what mine was doing:
Starting off in 1st the truck would literally rev up to about 5k rpms until I let my foot off the gas completely then it would skip second and shift to third. At that point since I didn't have the speed for 3rd the truck would bog and was around 1200 rpms (way too low). After that it wouldn't shift anymore, it would stay in 3rd at any speed even 70+mph

Tell me does your speedometer work?

Speedometer does work but I did notice temp gauge isn't working
A new ignition switch was put in recently due to lost keys.

If you take it to a transmission shop (any of them I believe)
They can hook up a scanner and drive it and that will tell them exactly what is going on as their scanners read live data.

I use Eagle Transmission personally, but last I checked most tranny shops do free diagnostics.

So if you want a for sure answer before tearing the tranny apart or looking into any other possible causes I'd get it diagnosed.

If I drove it personally I could tell you exactly what the problem is.
Believe me I've had just about every kind of transmission problem possible.

I bet you it ends up being that 2-4 band.