This problem is killing me. The car has a 2800 vigilante converter, transgo shift kit and was rebuilt about 35000 miles ago. It has a hypertech power programmer tune (i know it is crappy). I have to let off after I hit 5k or it just bounces off the rev limiter. Sometimes it will shift, but rarely. This happens in any gear. It also feels like it is constantly trying to downshift/bogg at any speed aslo. There is no ses light on. I replaced the fuel filter because I thought it might be clogged and it didn't fix it. I cleaned the maf and it didn't fix it and there were no air leaks after the maf (past problem). i put a new fuel pump in a couple of years ago. I replaced the water pump and opti 2 years ago also, both with gm parts. Today when I drove the car, it was surging at idle and would almost die, after I drove it 40 miles or so. I thought I would see if anyone had any ideas before I took it to the dealer for some sort of diagnoses. This is my weekend car, not my daily driver. Any help would be appreciated. It also has coated long tube headers and accel wires. It doesn't sound like it is missing or anything, but it doesn't feel as strong as it used to either. Thanks in advance!!

 

tranny fluid is normal pink color with no shavings or darkness in the fluid.

 

Had a similar problem, would bounce off the rev in 2nd. Put a tranny cooler in it and it quit. More then likely the trans fluid is just getting hot and losing viscosity. I put the tranny cooler in bout 5 months ago, took it to the track and hot lapped it for a total of four races and sat in the line. On the fourth run it WANTED to bounce but didn't. So just to keep everything safe since my tranny already had to be rebuilt once, I found a transmission pan from a 700R4, same thing as a 4L60E for my purposes, that had cooling tubes and an increased capacity. Fixed everything real good. I'd suggest trying to keep your tranny cool, thats what your problem sounds like.

 

the car has a tranny cooler on it. i had one installed when i had the tranny rebuilt the 1st time.

 

sounds like it may also be a vehicle speed sensor
your cars shift points are bassed on what the vss tells the computer your speed is
so if its going bad it can cause lots of odd ball tranny issues
i would check that out

 

where is that sensor located? on the tranny?

 

If it's wanting to die if you're at idle, I don't think it would be your transmission.

What you could try is starting your and let it run until it starts wanting to die, and let it. Then check your fuel pressure and check for spark.

Even though you replaced the opti-spark, it could still be that.

I had to replace my opti-spark 3 times in less than 5,000 miles (they're "suppose" to last 80,000) so you never know...

 

the idle issue went away on its own. It was some sort of fluke as it isnt doing it anymore. I do agree on the opti. I will be pissed if the opti is going out again!!!

 

I remember i had some sensor or harness unhooked near the pass side of the intake. You might want to check that out.

 

after i gutted my cat, it would bounce off my rev limiter second into third. (eveytime) i was told because of the free flowing exaust the car was reving slightly higher.

i got a hypertech programmer off ebay for cheap, adjusted the rev limiter to 6400 rpm, and havent had a prob...