why wont i accelerate

[mgrizz03]

whats the deal, my car, which is an earlier sunfire model, (sunbird) is having this really odd problem of exactly this:

i can accelerate fine up to 60 per say but in order to do this, i cannot push hard on the gas pedal...

if i do, it drops down to the one gear below, common in all cars, and revs high, now you would think the car would have a jolt forward as the engine revs quickly, (it used to do this) as the gas pedal is down close to the floor..

but nooooooo, my engine revs really high, and the car stays at the exact speed

so in order to beat this, i must let go of the gas a little, and let the engine take the step back up to the original gear and slowly gas up

i dont know if this helps but this problem is a lot worse when its not warmed up and been sitting say overnight, in temps at about 10-30, over in NY here, as i drive, the problem i described above seems to do a little better...


so heres the info: *1991 pontiac sunbird
*170,000 miles (yes i know this is shockingly high)
*new radiator
*new alternator
*oil changes and tune ups done often
*transmission sounds like its in good condition
*had a mechanic check it out and he said it doesnt
really sound like the transmission



HELLLLLLLP!!!!!!

[mgrizz03]

oh yea, and its a 2.0L 4 cyl engine

[hotrodamd]

check the fuel pressure make sure it meets required fuel pressure range started and with key on but engine off, make sure you change the fuel filter as this is a common problem on power loss, as you mentioned car will pick up speed at its own pace so when you press on accelerator you are actually depending on the fuel pump to match air intake and as you described the car will not accelerate until you depress the gass (or let up) which tells me that you just might have a loss of fuel pressure..




drive fast or be last...............

[b32780]

I had a similar problem. I changed the fuel filter and unfortunately that was not it. What sucked is that it was the fuel pump. BAM!! $250. What a pain in the arse. The gas tank had to come out and all kinds of fun stuff. However, as soon as it was back in and hooked up the bad boy fired right up. I've got a 97 sunfire with 184,000 miles. What a champion.

[hopeless4life]

It sounds like somethin to do with the transmission, check the throttle valve (TV) cable, (if it has one) Check the transmission fluid for particles etc. Change it if necessary. But i think that TV cable might be freezing up in the cold, needs some adjustment or attention with a BFH

[Leslie'sCustom]

I had the same problem with my 97 sunfire , in my case it was the transmission in addition to slipping when it dropped a gear it also did not acclerate as fast as usual staring in first gear sometimes. (i had to get a new tranny)

[Slade901]

It sounds like a partially clogged catalytic converter.

[Sound Gorillaz]

Or head gasket

[crazydriver7686]

check fluid level in transmission

[Sweet pea]

Hi there I have A 2000 sunfire and i too have had that same thing happen turns out i took it to my local garage and they put on some devive. it turned out to be my speed sensor gone he put in a new one 40 bucks later . not bad in price neither

[richtazz]

because the problem is worse when the car has sat or when it's cold out, I would agree with Hotrodamd and have your fuel pressure checked. If it is low, your problem is either the fuel pressure regulator or fuel pump. The car needs more fuel when cold as the engine requires a richer air/fuel mixture.