2001 Grand Am GT

[beavis1221]

Driving on the highway yesterday, went to pass, pushed on the accelerator and the engine went up to about 3500 rpm, but that's it. Car wouldn't get above 75mph.

I can slowly get it well over 80 if I don't mash the accelerator. Also noticed that at about 55 or 60 when passing through 2400 rpm, the rpm's jump up and down about 100 or 200 rpm.

Once you get to cruising speed it runs great.

So I get home last night after driving about 250 miles on the highway, put it in park, and the engine idles from about 300 rpm to 900 rpm. Up, down, up, down. WOuldn't quit until I shut the car off.

Any ideas?

[Gir-_-]

might of blown a gasket

But someone will get to this asap

[xeroinfinity]

Has someone beeen under the hood working on anything?

Sounds like a vacum leak.
Check around the intake and see if anything looks disconnected. With the car runing you should hear a whistling sound if theirs a Vacumm leak.

[89ltd]

also hook up a fuel pressure gauge and check the pressure, I just replaced a friends pump, It still would run but the check valve in the pump itself was toast and it just wouldn't pump.

[Gir-_-]

Originally Posted by xeroinfinity

Has someone beeen under the hood working on anything?

Sounds like a vacum leak.
Check around the intake and see if anything looks disconnected. With the car runing you should hear a whistling sound if theirs a Vacumm leak.

note on that, the big black tube in the intake right before the throttle body ... also maybe the PVC could be unhooked or u need a new one possibly.. not saying you do.... but on the other end of that same PCV hose it might of been disconnected in the back of the engine...

Like Xero said you would probly hear a whistle like sound....

[daman]

When was the last GOOD tune up??

fuel filter getting clogged???

[xeroinfinity]

If thiers no vacum leaks, and your Fuel pressure is between 41-47psi, then check your IAC, it could be dirty/malfuntioning.
The EGR can also get pluged and it'll cause simular symptoms .

Pretty easy to clean the IAC with TB cleaner, just dont turn the tip.

Also hav you evr replaced the fuel filter?
That'll cause it to not want to accelerate properly.

Hope this helps