2001 grand am issues

[Rubberman]

I bought a 2001 grand am with the 2.4l for my daughter who got her license a couple weeks ago.

when I bought it the idle was High. I cleaned the throttle body and that brought it down below 1000rpms. At idling in drive Is rough. Previous owner replaced the throttle position sensor but should i try replacing the air idle control valve?

i will be giving it a tuneup this weekend by replacing the spark plugs, fuel filter , air filter. Maybe that will help the idle.

also on the fuel pump which the previous owner replaced last year is having gas gauge issues where it only shows 1/4 tank of gas. Should replace the whole pump assembly? They already cut an access hole under the seat seat.

 

[melsg5]

Do you have a check engine light on?
I would suspect the IAC or a vacuum leak.
Pull the pump and try to test the float to see if it has full movement and shows the correct reading for full and empty.

 

[Rubberman]

No check engine lights. Are the only vac lines the ones coming from the throttle body? There are 3-4 coming from there.

 

[melsg5]

I do not have a vacuum line diagram

______________________________

 

[Rubberman]

I pulled the pump and noticed some of the contacts tarnished up. Also didn't seem to be rubbing so I cleaned them and I thought I adjusted them to make more contact. Now the gauge reads either Full or Empty. I guess I will need to get a new pump.

I used my Autel and it showed no misfires but it really runs rough at idle with the AC on. Scanner shows it idling at 590-610 rpms but If I give it gas to 650ism rpms then the roughness stops. I haven't replaced the idle air control valve yet but it seems to move when I give it power.

 

[Rubberman]

Replaced the air filter, idle air sensor, throttle position sensor, and it still idles like crap. I’ll be changing the fuel filter and spark plugs next. I do have an O2 sensor(sensor1) code with closed loop and insufficient activity.

also on the fuel trims i get 0 for short term and long term. I have tried 2 different t scanners and both show 0.