Chevy blazer loses power

2000 Chev Blazer
4.3
auto
4wd

loses power intermittently then gets better, hit the gas and it will seem like it is stalling out, no power at all, then it will suddenly kick back in and drive fine. Seems to have no pattern.

I have replaced:
Plugs
Cap
Rotor
Coil
CPS
put flush in the tranny
flushed and changed the oil
fuel pump is newish

I am running out of ideas, maybe the dizzy?

seriously, this is killing me

There is a bulletin about a condition similar to this for vehicles with the 4.3 and 4l60e combo.. If there are no DTC's and it happens more when cold.. and the vehicle seems to be missing..You'll need to take it to a dealership and they will open a TAC case.. The only information given about the condition is the technician is supposed to record the trans fluid pressure switch status and readings.. It sounds like a peice of mettalic debris will float across the switch temporarily activating or sending false signals to the pcm causing the vehicle to freak out. I'll dig for more info.

sweetness, any chance that there is a recall on this and I can get out for cheap? Kinda pisses me off cause I asked a service writer about it and he said that there were no bullitins at all.

If this is the case I wonder what a tranny fluid replacement and filter change would do for it.

thanks for looking into it for me, wife is getting a bit antsy about her truck freaking out

No recall... here is the bulletin I found that may match to your problem.. A trans service might help..I would want to take a look at the trans pressure switch.. Look and see if it is all gunked up. The switch is bolted to your valvebody.. I don't remember how many bolts but it is between the filter and valvebody..How often does this happen and are there any DTC's?

PIP3796A: Loss of Power Hesitates on Acceleration - keywords 2.8 3.5 4.2 4.3 4.8 4L60E 4L65E 5.3 5.7 6.0 accelerate cold L35LK5 LL8 LM7 loss LQ4 LQ9 LS1 LS6 LU3 M30 M32 miss misfire neutral no performance power - (Aug 14, 2006)

sweet thanks man

It was throwing trouble codes but we couldnt figure out how to relate them

o2 sensor bank one sensor 2 high inputs
-I usually assume this to not be a problem with the sensor but that the truck is running rich on that bank

random multiple cylinder misfire
-makes the o2 sensor code a definate rich condition and not a sensor problem- car is not burning the gas so the o2 sensor sees it

It does seem to be an initial startup problem as I dont think it has ever done it (at least not terribly) except for shortly after we have jumped into the truck to go somewhere.

I got the switch today, and there is not a lot to it, I will see if it is gunked up, if it is I guess I will replace it, I dont suppose it is something that can be cleaned and reused is it?

FWIW... You might want to fix your driveability problem first... Usually when the sensor 2 circuit is reading rich means your cat is bad.. the sensor 2 o2 ensors only monitor the effectiveness of the cat..
I beleive you have whats refered to in the dealer world as spider injection.. Those are famous for problems as well. Which may be causing the misfire.. You should chase those issues first..The misfire code could easily be you problem..How many miles on the rig?
The bulletin I refered to earlier pertains to the described performance if no DTC's are present..

aight, ill look into these as well