No Power

I have a 2001 Chevy Lumina, I hate this car. When I purchased the car everything was fine. Now I can't drive over 55 and even that is getting to be tricky. I will be driving and all of a sudden, even though I am doing 55 and have gone through all of the gears the car will start to buck and I lose power. Sometimes if I just ride out the bucking all of a sudden it will act like it shifts but not really and I gain power again for a moment. Then the car motor starts to surge. I have to pull over to the side of the road, turn the car off, count slowly to 10 start the car, wait for all of the lights to go off on the dash, then pull back out into traffic with the car chugging and backfiring. It is a pain in the rear and I have had about 90 different diagnosis given to me from the tranny to the fuel pump to the radiator, and the air intake filters. I have flushed the cooling system, checked the tranny fluid, it is fine a bit dark but no metal and not burned. I have had the fuel injector filters changed and have had the garage clean the injector. I have had one of the air intake filters changed but from what I was told the other one is beneath the engine?. Help please as I am ready to take it to a rural road and shoot the stupid thing and take my chances walking back and forth to town.

OK...I see your frustration.

I can tell by your post that you are not particularly car savvy, and you seem to be talking to some real dinks posing as mechanics....

This would drive anyone off the edge.

First off, which motor, and how many miles?

Is the check engine light on? If so, was it read for codes? If so, what were they? If not, this needs to be done first.

Just based on what I can gather from your description, it sounds like the car is able to cruise under very light load at speed, but even a slight increase in throttle input puts it into a spell of surging and bucking?

How does it do from a stop, under heavy throttle? Is it only apparent when trying to cruise in top gear? So when it backshifts to a lower gear momentarily it can pick up revs, but falls on its face again once it returns to overdrive?

Just from the description, if it were my car and I had no code info to help, I'd replace the fuel filter first. This is located under the car, back by the fuel tank. It sounds like they already did this.

Next step would be to drive it with a fuel pressure gauge in place, and watch fuel pressure as the problem occurs. If pressure remains constant during the trouble, you can forget fuel pump/pump relay/pressure regulator issues, and focus elsewhere...but my guess is this is where the problem lies...

I doubt the tranny is involved...there is an issue called torque convertor shudder that can affect these cars, but not the way you describe...it's more of a bucking while cruising that goes away when you drop down and accelerate...it sounds like yours sags and bucks the harder you step down on it, until it backshifts, yes?

Anyway, your problem really sounds like fuel starvation under load, as far as I can tell. Verify this, and you'll at least have a direction to proceed in. Throwing parts at it until you get it right is going to prove much more expensive in the long run than biting the bullet and paying for a proper diagnosis....

I have had the fuel filter changed twice thinking this may be the problem.

As for when does it do this, I can be pulling out of the driveway and it will not get a good drink and start to buck and carry on. I have to baby it down the street and about three quarters of the way it then decides to drive and I have no problems until I hit the highway. Then I have to pull out slowly and accelerate slowly taking my foot off of the accelerator pedal at certain shifting points to get it to shift and not bog down on me. If it is particularly cold outside I'm doomed until I get the stupid thing warmed up, even if I start it to warm up.

Yes the check engine light is on, so I took it to Auto Zone and had them put it on the machine for codes and they said all I needed was to have the air intake filter changed so I did and it was no help. The car has 123,309 on it and the motor is a 3.1 liter YGMXV03.4041 YGMXR0133918. It is also a 2000 not a 2001.

I would suggest at this point you post the exact cel code for a proper diagnosis here.

A few years back my '96 acted similar.
Ended up being a plugged catylic converter.
It would idle OK, but could not accellerate and had no power either. A lot of the popping was out of the intake, so I origionally thought fuel too.