'99 blazer loss of rpm's and horse pwr

I've got a 99 LS blazer that has about 72,000 miles on it, my problem is that I lose rmps when I hit the accelerator and the rmp's go down, but I will gradually gain speed. When I first got it it had more than enough power, but now its lacking. Does anyone have any ideas? Thank you.

A simple tune-up must be checked first. Have the Air & Fuel filters been replaced recently?

If those are OK, I would check fuel pressure.

I'm having the same trouble with my 99 Blazer 4.3L. So far I've replaced the transfer case control motor, spark plugs & wires, fuel filter, air filter, and O2 sensor. I'm taking it back to my mechanic today. It only hesitates (like it's not getting enough fuel) between 15 and 25 mph. My rpms drop and rise. Once I hit 25 mph, it runs great.

I've gotten a tune up, the spark plugs, distributor, fuel filter, air filter, all that and it still feels sluggish and the rpms run low. It will actually jump in rmps when you hit the gas, then it drops again slowly increasing in speed. Sound funny?

I had a similar issue a while ago in my '00 4.3L ZR2. You might try replacing the MAF sensor and reset the computer.

Matt

I took my 99 Blazer back to my mechanic yesterday. He checked the code P1875 on ALLDATA, which related to the transmission. Seems to be a very common code on this particular make/model. So he took it for a test drive (novel idea -- isn't this the way mechanics used to determine a problem before computers). Returned 15 minutes later saying it's definitely the tranny. It's slipping between 1st & 2nd gear (15-25 mph). Yikes. Back to the Chevy dealer's garage with checkbook in hand. Hope this isn't the same problem you're experiencing.

I had my transmission checked out, the mechanic drove it around for a while. He said nothing was wrong with it, it didn't even need a flush. I think that it might be the computer itself.

does your exhaust smell liek rotton eggs?

Put your hand over the exhaust tailpipe, how much is coming out?

My exhaust doesn't smell, but it does sound different than when I got it. Do you think I might have an exhaust leak that is causing the losses I'm experiencing?

Does it sound like it is growling a bit?

Chances are you have a completely plugged Catalytic convertor.

Time to get it changed bro.

So you really think it could be that easy? Hey I'll try that, how much for all new pipes you think? (Nice ones, not from the dealer ship)

Well, I am not 100% sure, but a clogged cat does have those symptoms.

Go to the dealership and have them do a back pressure test between the engine and the cat.

Any pressure at all and your cat is shot.

Also, you can never get any better than the stock exhausts on the blazer.

The metal lasts forever.

had the same problem on my 2000 blazer and guess what almost every part/ sensor was changed and nothing fixed it untill ...see the end , also i went to a transmission shop and they said the transmission was fine and the truck drove fine, i didnt agree i felt the truck HAD A PROBLEM loss of power almost felt like my automatic transmission was starting out in 2nd gear from a dead stop, of course every mechanic and the transmission mechanic that drove my truck where older men like 55 or so and they barely simulated how i really drive in nyc manhattan traffic when they test drove the truck. but i never gave up i went to my 2nd transmission place and still they said no codes scan nothing is wrong they said maybe its the driver i wass pissed i know how to drive and i knew this truck had a problem so on my 3rd visit to a different transmission shop a younger guy around 35 drives the truck and tells me i got a problem this truck should have more power they were the words i was longing to hear.. he did a simple stall test when you put the gear in drive and hold the brake down and give it gas floor the gas pedal and watch your rpm's he said to me i have a bad tourque converter i said they were no codes he said forget that a simple stall test can be very effective he was right problem solved !
remedy replaced tourque converter
truck drives better than new and has awesome power now email me if you have any questions

Hey, SO how much and how long did it take to do this torque converter replacement?

the bill was 800.00 total for the converter fluid etc. it took the trans shop 1 day...

Hey, SO how much and how long did it take to do this torque converter replacement?

Get a backpressure check before you start to rip apart your motor.

All they do is remove the O2 sensor before the cat and attach a pressure gauge.